mirror of
https://github.com/torvalds/linux
synced 2024-07-21 10:41:44 +00:00
2445 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
a4aebe9365 |
posix-timers: Get rid of [COMPAT_]SYS_NI() uses
Only the posix timer system calls use this (when the posix timer support is disabled, which does not actually happen in any normal case), because they had debug code to print out a warning about missing system calls. Get rid of that special case, and just use the standard COND_SYSCALL interface that creates weak system call stubs that return -ENOSYS for when the system call does not exist. This fixes a kCFI issue with the SYS_NI() hackery: CFI failure at int80_emulation+0x67/0xb0 (target: sys_ni_posix_timers+0x0/0x70; expected type: 0xb02b34d9) WARNING: CPU: 0 PID: 48 at int80_emulation+0x67/0xb0 Reported-by: kernel test robot <oliver.sang@intel.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Sami Tolvanen <samitolvanen@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Anna-Maria Behnsen
|
da65f29dad |
timers: Fix nextevt calculation when no timers are pending
When no timer is queued into an empty timer base, the next_expiry will not be updated. It was originally calculated as base->clk + NEXT_TIMER_MAX_DELTA When the timer base stays empty long enough (> NEXT_TIMER_MAX_DELTA), the next_expiry value of the empty base suggests that there is a timer pending soon. This might be more a kind of a theoretical problem, but the fix doesn't hurt. Use only base->next_expiry value as nextevt when timers are pending. Otherwise nextevt will be jiffies + NEXT_TIMER_MAX_DELTA. As all information is in place, update base->next_expiry value of the empty timer base as well. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-13-anna-maria@linutronix.de |
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Thomas Gleixner
|
bb8caad508 |
timers: Rework idle logic
To improve readability of the code, split base->idle calculation and expires calculation into separate parts. While at it, update the comment about timer base idle marking. Thereby the following subtle change happens if the next event is just one jiffy ahead and the tick was already stopped: Originally base->is_idle remains true in this situation. Now base->is_idle turns to false. This may spare an IPI if a timer is enqueued remotely to an idle CPU that is going to tick on the next jiffy. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-12-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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7a39a5080e |
timers: Use already existing function for forwarding timer base
There is an already existing function for forwarding the timer base. Forwarding the timer base is implemented directly in get_next_timer_interrupt() as well. Remove the code duplication and invoke __forward_timer_base() instead. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-11-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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1e490484aa |
timers: Split out forward timer base functionality
Forwarding timer base is done when the next expiry value is calculated and when a new timer is enqueued. When the next expiry value is calculated the jiffies value is already available and does not need to be reread a second time. Splitting out the forward timer base functionality to make it executable via both contextes - those where jiffies are already known and those, where jiffies need to be read. No functional change. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-10-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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8a2c9c7e78 |
timers: Clarify check in forward_timer_base()
The current check whether a forward of the timer base is required can be
simplified by using an already existing comparison function which is easier
to read. The related comment is outdated and was not updated when the check
changed in commit
|
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Anna-Maria Behnsen
|
b5e6f59888 |
timers: Move store of next event into __next_timer_interrupt()
Both call sites of __next_timer_interrupt() store the return value directly in base->next_expiry. Move the store into __next_timer_interrupt() and to make its purpose more clear, rename the function to next_expiry_recalc(). No functional change. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-8-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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d124c3393e |
timers: Do not IPI for deferrable timers
Deferrable timers do not prevent CPU from going idle and are not taken into account on idle path. Sending an IPI to a remote CPU when a new first deferrable timer was enqueued will wake up the remote CPU but nothing will be done regarding the deferrable timers. Drop IPI completely when a new first deferrable timer was enqueued. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-7-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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b573c73101 |
tracing/timers: Add tracepoint for tracking timer base is_idle flag
When debugging timer code the timer tracepoints are very important. There is no tracepoint when the is_idle flag of the timer base changes. Instead of always adding manually trace_printk(), add tracepoints which can be easily enabled whenever required. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-6-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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dbcdcb62b5 |
tracing/timers: Enhance timer_start tracepoint
For starting a timer, the timer is enqueued into a bucket of the timer wheel. The bucket expiry is the defacto expiry of the timer but it is not equal the timer expiry because of increasing granularity when bucket is in a higher level of the wheel. To be able to figure out in a trace whether a timer expired in time or not, the bucket expiry time is required as well. Add bucket expiry time to the timer_start tracepoint and thereby simplify the arguments. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-5-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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cbf04a2202 |
tick-sched: Warn when next tick seems to be in the past
When the next tick is in the past, the delta between basemono and the next tick gets negativ. But the next tick should never be in the past. The negative effect of a wrong next tick might be a stop of the tick and timers might expire late. To prevent expensive debugging when changing underlying code, add a WARN_ON_ONCE into this code path. To prevent complete misbehaviour, also reset next_tick to basemono in this case. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-4-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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318050671a |
tick/sched: Cleanup confusing variables
tick_nohz_stop_tick() contains the expires (u64 variable) and tick (ktime_t) variable. In the beginning the value of expires is written to tick. Afterwards none of the variables is changed. They are only used for checks. Drop the not required variable tick and use always expires instead. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-3-anna-maria@linutronix.de |
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Anna-Maria Behnsen
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cb665db94f |
tick-sched: Fix function names in comments
When referencing functions in comments, it might be helpful to use full function names (including the prefix) to be able to find it when grepping. Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20231201092654.34614-2-anna-maria@linutronix.de |
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Arnd Bergmann
|
a89299c409 |
time: Make sysfs_get_uname() function visible in header
This function is defined globally in clocksource.c and used conditionally in clockevent.c, which the declaration hidden when clockevent support is disabled. This causes a harmless warning in the definition: kernel/time/clocksource.c:1324:9: warning: no previous prototype for 'sysfs_get_uname' [-Wmissing-prototypes] 1324 | ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt) Move the declaration out of the #ifdef so it is always visible. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231108125843.3806765-5-arnd@kernel.org |
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Linus Torvalds
|
b0014556a2 |
- Do the push of pending hrtimers away from a CPU which is being
offlined earlier in the offlining process in order to prevent a deadlock -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmVaB28ACgkQEsHwGGHe VUr3ZBAAwOLL5vimHB3Y59cTRLPN+zGKhzyVLMLnbkKs4sGJ+9srP4HLX4Q9PoAb kR9Hzq90+48YuyLe+S/R2pvm1x88K33spS+4w4fl3x6EeToqvUlop2GPuMS2yzXY yECdqCLEd3Q6DeI8hN35lv899qyfGSD+6WxezLCT+uwx6AMHljMAsDy2249UtMZv 1bqZnYCtN2zv3MQuV1uli/AVxTDv4vXcumza17inuw0IpEA26Wz2kWruxeyZnUXU /sWZudUdhiErfg428ok3oTL1BOwPzyiIWjhN2MzqlKFmyp463DwV7KoAc3SxYINE 8qbODN93CFdnU6h29+VQoRxO9vcmWL6w7A/Swc9ar/0/Qnt7H9JdzUKtJ4+EaTCY /IpRWcNcX4WI6BKuHHl6kOBvX3YW77PKaIsxj8JDNZTMk6rq6lMGi+tIaVsAki92 3MQZ9+Lkm0baykIZAWz4jajbA98KvJMeJ60qZQI6sWWdpyrncEqG9pH/ulkLY4aZ gT94LiRpdwT0LWrX0J6xPMTNi9NYWjdB/uyo6Drer42SB9J7ol4rAbOxs50srG8i z46VGDtgWz6C5MSkonhQqrpGzc/HF9xCWVVSF1UENT4K+2W55JhJrDZBs5XCPJiz Bj8T3Maz7wcVkA41DA7C5xlVed+ST1ID8/4y5cWImnrmWOdG5Zw= =Tekh -----END PGP SIGNATURE----- Merge tag 'timers_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Borislav Petkov: - Do the push of pending hrtimers away from a CPU which is being offlined earlier in the offlining process in order to prevent a deadlock * tag 'timers_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimers: Push pending hrtimers away from outgoing CPU earlier |
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Thomas Gleixner
|
5c0930ccaa |
hrtimers: Push pending hrtimers away from outgoing CPU earlier
|
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|
Linus Torvalds
|
89ed67ef12 |
Networking changes for 6.7.
Core & protocols
----------------
- Support usec resolution of TCP timestamps, enabled selectively by
a route attribute.
- Defer regular TCP ACK while processing socket backlog, try to send
a cumulative ACK at the end. Increase single TCP flow performance
on a 200Gbit NIC by 20% (100Gbit -> 120Gbit).
- The Fair Queuing (FQ) packet scheduler:
- add built-in 3 band prio / WRR scheduling
- support bypass if the qdisc is mostly idle (5% speed up for TCP RR)
- improve inactive flow reporting
- optimize the layout of structures for better cache locality
- Support TCP Authentication Option (RFC 5925, TCP-AO), a more modern
replacement for the old MD5 option.
- Add more retransmission timeout (RTO) related statistics to TCP_INFO.
- Support sending fragmented skbs over vsock sockets.
- Make sure we send SIGPIPE for vsock sockets if socket was shutdown().
- Add sysctl for ignoring lower limit on lifetime in Router
Advertisement PIO, based on an in-progress IETF draft.
- Add sysctl to control activation of TCP ping-pong mode.
- Add sysctl to make connection timeout in MPTCP configurable.
- Support rcvlowat and notsent_lowat on MPTCP sockets, to help apps
limit the number of wakeups.
- Support netlink GET for MDB (multicast forwarding), allowing user
space to request a single MDB entry instead of dumping the entire
table.
- Support selective FDB flushing in the VXLAN tunnel driver.
- Allow limiting learned FDB entries in bridges, prevent OOM attacks.
- Allow controlling via configfs netconsole targets which were created
via the kernel cmdline at boot, rather than via configfs at runtime.
- Support multiple PTP timestamp event queue readers with different
filters.
- MCTP over I3C.
BPF
---
- Add new veth-like netdevice where BPF program defines the logic
of the xmit routine. It can operate in L3 and L2 mode.
- Support exceptions - allow asserting conditions which should
never be true but are hard for the verifier to infer.
With some extra flexibility around handling of the exit / failure.
https://lwn.net/Articles/938435/
- Add support for local per-cpu kptr, allow allocating and storing
per-cpu objects in maps. Access to those objects operates on
the value for the current CPU. This allows to deprecate local
one-off implementations of per-CPU storage like
BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE maps.
- Extend cgroup BPF sockaddr hooks for UNIX sockets. The use case is
for systemd to re-implement the LogNamespace feature which allows
running multiple instances of systemd-journald to process the logs
of different services.
- Enable open-coded task_vma iteration, after maple tree conversion
made it hard to directly walk VMAs in tracing programs.
- Add open-coded task, css_task and css iterator support.
One of the use cases is customizable OOM victim selection via BPF.
- Allow source address selection with bpf_*_fib_lookup().
- Add ability to pin BPF timer to the current CPU.
- Prevent creation of infinite loops by combining tail calls and
fentry/fexit programs.
- Add missed stats for kprobes to retrieve the number of missed kprobe
executions and subsequent executions of BPF programs.
- Inherit system settings for CPU security mitigations.
- Add BPF v4 CPU instruction support for arm32 and s390x.
Changes to common code
----------------------
- overflow: add DEFINE_FLEX() for on-stack definition of structs
with flexible array members.
- Process doc update with more guidance for reviewers.
Driver API
----------
- Simplify locking in WiFi (cfg80211 and mac80211 layers), use wiphy
mutex in most places and remove a lot of smaller locks.
- Create a common DPLL configuration API. Allow configuring
and querying state of PLL circuits used for clock syntonization,
in network time distribution.
- Unify fragmented and full page allocation APIs in page pool code.
Let drivers be ignorant of PAGE_SIZE.
- Rework PHY state machine to avoid races with calls to phy_stop().
- Notify DSA drivers of MAC address changes on user ports, improve
correctness of offloads which depend on matching port MAC addresses.
- Allow antenna control on injected WiFi frames.
- Reduce the number of variants of napi_schedule().
- Simplify error handling when composing devlink health messages.
Misc
----
- A lot of KCSAN data race "fixes", from Eric.
- A lot of __counted_by() annotations, from Kees.
- A lot of strncpy -> strscpy and printf format fixes.
- Replace master/slave terminology with conduit/user in DSA drivers.
- Handful of KUnit tests for netdev and WiFi core.
Removed
-------
- AppleTalk COPS.
- AppleTalk ipddp.
- TI AR7 CPMAC Ethernet driver.
Drivers
-------
- Ethernet high-speed NICs:
- Intel (100G, ice, idpf):
- add a driver for the Intel E2000 IPUs
- make CRC/FCS stripping configurable
- cross-timestamping for E823 devices
- basic support for E830 devices
- use aux-bus for managing client drivers
- i40e: report firmware versions via devlink
- nVidia/Mellanox:
- support 4-port NICs
- increase max number of channels to 256
- optimize / parallelize SF creation flow
- Broadcom (bnxt):
- enhance NIC temperature reporting
- support PAM4 speeds and lane configuration
- Marvell OcteonTX2:
- PTP pulse-per-second output support
- enable hardware timestamping for VFs
- Solarflare/AMD:
- conntrack NAT offload and offload for tunnels
- Wangxun (ngbe/txgbe):
- expose HW statistics
- Pensando/AMD:
- support PCI level reset
- narrow down the condition under which skbs are linearized
- Netronome/Corigine (nfp):
- support CHACHA20-POLY1305 crypto in IPsec offload
- Ethernet NICs embedded, slower, virtual:
- Synopsys (stmmac):
- add Loongson-1 SoC support
- enable use of HW queues with no offload capabilities
- enable PPS input support on all 5 channels
- increase TX coalesce timer to 5ms
- RealTek USB (r8152): improve efficiency of Rx by using GRO frags
- xen: support SW packet timestamping
- add drivers for implementations based on TI's PRUSS (AM64x EVM)
- nVidia/Mellanox Ethernet datacenter switches:
- avoid poor HW resource use on Spectrum-4 by better block selection
for IPv6 multicast forwarding and ordering of blocks in ACL region
- Ethernet embedded switches:
- Microchip:
- support configuring the drive strength for EMI compliance
- ksz9477: partial ACL support
- ksz9477: HSR offload
- ksz9477: Wake on LAN
- Realtek:
- rtl8366rb: respect device tree config of the CPU port
- Ethernet PHYs:
- support Broadcom BCM5221 PHYs
- TI dp83867: support hardware LED blinking
- CAN:
- add support for Linux-PHY based CAN transceivers
- at91_can: clean up and use rx-offload helpers
- WiFi:
- MediaTek (mt76):
- new sub-driver for mt7925 USB/PCIe devices
- HW wireless <> Ethernet bridging in MT7988 chips
- mt7603/mt7628 stability improvements
- Qualcomm (ath12k):
- WCN7850:
- enable 320 MHz channels in 6 GHz band
- hardware rfkill support
- enable IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS
to make scan faster
- read board data variant name from SMBIOS
- QCN9274: mesh support
- RealTek (rtw89):
- TDMA-based multi-channel concurrency (MCC)
- Silicon Labs (wfx):
- Remain-On-Channel (ROC) support
- Bluetooth:
- ISO: many improvements for broadcast support
- mark BCM4378/BCM4387 as BROKEN_LE_CODED
- add support for QCA2066
- btmtksdio: enable Bluetooth wakeup from suspend
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Support usec resolution of TCP timestamps, enabled selectively by a
route attribute.
- Defer regular TCP ACK while processing socket backlog, try to send
a cumulative ACK at the end. Increase single TCP flow performance
on a 200Gbit NIC by 20% (100Gbit -> 120Gbit).
- The Fair Queuing (FQ) packet scheduler:
- add built-in 3 band prio / WRR scheduling
- support bypass if the qdisc is mostly idle (5% speed up for TCP RR)
- improve inactive flow reporting
- optimize the layout of structures for better cache locality
- Support TCP Authentication Option (RFC 5925, TCP-AO), a more modern
replacement for the old MD5 option.
- Add more retransmission timeout (RTO) related statistics to
TCP_INFO.
- Support sending fragmented skbs over vsock sockets.
- Make sure we send SIGPIPE for vsock sockets if socket was
shutdown().
- Add sysctl for ignoring lower limit on lifetime in Router
Advertisement PIO, based on an in-progress IETF draft.
- Add sysctl to control activation of TCP ping-pong mode.
- Add sysctl to make connection timeout in MPTCP configurable.
- Support rcvlowat and notsent_lowat on MPTCP sockets, to help apps
limit the number of wakeups.
- Support netlink GET for MDB (multicast forwarding), allowing user
space to request a single MDB entry instead of dumping the entire
table.
- Support selective FDB flushing in the VXLAN tunnel driver.
- Allow limiting learned FDB entries in bridges, prevent OOM attacks.
- Allow controlling via configfs netconsole targets which were
created via the kernel cmdline at boot, rather than via configfs at
runtime.
- Support multiple PTP timestamp event queue readers with different
filters.
- MCTP over I3C.
BPF:
- Add new veth-like netdevice where BPF program defines the logic of
the xmit routine. It can operate in L3 and L2 mode.
- Support exceptions - allow asserting conditions which should never
be true but are hard for the verifier to infer. With some extra
flexibility around handling of the exit / failure:
https://lwn.net/Articles/938435/
- Add support for local per-cpu kptr, allow allocating and storing
per-cpu objects in maps. Access to those objects operates on the
value for the current CPU.
This allows to deprecate local one-off implementations of per-CPU
storage like BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE maps.
- Extend cgroup BPF sockaddr hooks for UNIX sockets. The use case is
for systemd to re-implement the LogNamespace feature which allows
running multiple instances of systemd-journald to process the logs
of different services.
- Enable open-coded task_vma iteration, after maple tree conversion
made it hard to directly walk VMAs in tracing programs.
- Add open-coded task, css_task and css iterator support. One of the
use cases is customizable OOM victim selection via BPF.
- Allow source address selection with bpf_*_fib_lookup().
- Add ability to pin BPF timer to the current CPU.
- Prevent creation of infinite loops by combining tail calls and
fentry/fexit programs.
- Add missed stats for kprobes to retrieve the number of missed
kprobe executions and subsequent executions of BPF programs.
- Inherit system settings for CPU security mitigations.
- Add BPF v4 CPU instruction support for arm32 and s390x.
Changes to common code:
- overflow: add DEFINE_FLEX() for on-stack definition of structs with
flexible array members.
- Process doc update with more guidance for reviewers.
Driver API:
- Simplify locking in WiFi (cfg80211 and mac80211 layers), use wiphy
mutex in most places and remove a lot of smaller locks.
- Create a common DPLL configuration API. Allow configuring and
querying state of PLL circuits used for clock syntonization, in
network time distribution.
- Unify fragmented and full page allocation APIs in page pool code.
Let drivers be ignorant of PAGE_SIZE.
- Rework PHY state machine to avoid races with calls to phy_stop().
- Notify DSA drivers of MAC address changes on user ports, improve
correctness of offloads which depend on matching port MAC
addresses.
- Allow antenna control on injected WiFi frames.
- Reduce the number of variants of napi_schedule().
- Simplify error handling when composing devlink health messages.
Misc:
- A lot of KCSAN data race "fixes", from Eric.
- A lot of __counted_by() annotations, from Kees.
- A lot of strncpy -> strscpy and printf format fixes.
- Replace master/slave terminology with conduit/user in DSA drivers.
- Handful of KUnit tests for netdev and WiFi core.
Removed:
- AppleTalk COPS.
- AppleTalk ipddp.
- TI AR7 CPMAC Ethernet driver.
Drivers:
- Ethernet high-speed NICs:
- Intel (100G, ice, idpf):
- add a driver for the Intel E2000 IPUs
- make CRC/FCS stripping configurable
- cross-timestamping for E823 devices
- basic support for E830 devices
- use aux-bus for managing client drivers
- i40e: report firmware versions via devlink
- nVidia/Mellanox:
- support 4-port NICs
- increase max number of channels to 256
- optimize / parallelize SF creation flow
- Broadcom (bnxt):
- enhance NIC temperature reporting
- support PAM4 speeds and lane configuration
- Marvell OcteonTX2:
- PTP pulse-per-second output support
- enable hardware timestamping for VFs
- Solarflare/AMD:
- conntrack NAT offload and offload for tunnels
- Wangxun (ngbe/txgbe):
- expose HW statistics
- Pensando/AMD:
- support PCI level reset
- narrow down the condition under which skbs are linearized
- Netronome/Corigine (nfp):
- support CHACHA20-POLY1305 crypto in IPsec offload
- Ethernet NICs embedded, slower, virtual:
- Synopsys (stmmac):
- add Loongson-1 SoC support
- enable use of HW queues with no offload capabilities
- enable PPS input support on all 5 channels
- increase TX coalesce timer to 5ms
- RealTek USB (r8152): improve efficiency of Rx by using GRO frags
- xen: support SW packet timestamping
- add drivers for implementations based on TI's PRUSS (AM64x EVM)
- nVidia/Mellanox Ethernet datacenter switches:
- avoid poor HW resource use on Spectrum-4 by better block
selection for IPv6 multicast forwarding and ordering of blocks
in ACL region
- Ethernet embedded switches:
- Microchip:
- support configuring the drive strength for EMI compliance
- ksz9477: partial ACL support
- ksz9477: HSR offload
- ksz9477: Wake on LAN
- Realtek:
- rtl8366rb: respect device tree config of the CPU port
- Ethernet PHYs:
- support Broadcom BCM5221 PHYs
- TI dp83867: support hardware LED blinking
- CAN:
- add support for Linux-PHY based CAN transceivers
- at91_can: clean up and use rx-offload helpers
- WiFi:
- MediaTek (mt76):
- new sub-driver for mt7925 USB/PCIe devices
- HW wireless <> Ethernet bridging in MT7988 chips
- mt7603/mt7628 stability improvements
- Qualcomm (ath12k):
- WCN7850:
- enable 320 MHz channels in 6 GHz band
- hardware rfkill support
- enable IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS to
make scan faster
- read board data variant name from SMBIOS
- QCN9274: mesh support
- RealTek (rtw89):
- TDMA-based multi-channel concurrency (MCC)
- Silicon Labs (wfx):
- Remain-On-Channel (ROC) support
- Bluetooth:
- ISO: many improvements for broadcast support
- mark BCM4378/BCM4387 as BROKEN_LE_CODED
- add support for QCA2066
- btmtksdio: enable Bluetooth wakeup from suspend"
* tag 'net-next-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1816 commits)
net: pcs: xpcs: Add 2500BASE-X case in get state for XPCS drivers
net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos()
net: mana: Use xdp_set_features_flag instead of direct assignment
vxlan: Cleanup IFLA_VXLAN_PORT_RANGE entry in vxlan_get_size()
iavf: delete the iavf client interface
iavf: add a common function for undoing the interrupt scheme
iavf: use unregister_netdev
iavf: rely on netdev's own registered state
iavf: fix the waiting time for initial reset
iavf: in iavf_down, don't queue watchdog_task if comms failed
iavf: simplify mutex_trylock+sleep loops
iavf: fix comments about old bit locks
doc/netlink: Update schema to support cmd-cnt-name and cmd-max-name
tools: ynl: introduce option to process unknown attributes or types
ipvlan: properly track tx_errors
netdevsim: Block until all devices are released
nfp: using napi_build_skb() to replace build_skb()
net: dsa: microchip: ksz9477: Fix spelling mistake "Enery" -> "Energy"
net: dsa: microchip: Ensure Stable PME Pin State for Wake-on-LAN
net: dsa: microchip: Refactor switch shutdown routine for WoL preparation
...
|
||
|
Xabier Marquiegui
|
60c6946675 |
posix-clock: introduce posix_clock_context concept
Add the necessary structure to support custom private-data per posix-clock user. The previous implementation of posix-clock assumed all file open instances need access to the same clock structure on private_data. The need for individual data structures per file open instance has been identified when developing support for multiple timestamp event queue users for ptp_clock. Signed-off-by: Xabier Marquiegui <reibax@gmail.com> Suggested-by: Richard Cochran <richardcochran@gmail.com> Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
||
|
Guenter Roeck
|
8ceea12d18 |
alarmtimer: Use maximum alarm time for suspend
Some userspace applications use timerfd_create() to request wakeups after
a long period of time. For example, a backup application may request a
wakeup once per week. This is perfectly fine as long as the system does
not try to suspend. However, if the system tries to suspend and the
system's RTC does not support the required alarm timeout, the suspend
operation will fail with an error such as
rtc_cmos 00:01: Alarms can be up to one day in the future
PM: dpm_run_callback(): platform_pm_suspend+0x0/0x4a returns -22
alarmtimer alarmtimer.4.auto: platform_pm_suspend+0x0/0x4a returned -22 after 117 usecs
PM: Device alarmtimer.4.auto failed to suspend: error -22
This results in a refusal to suspend the system, causing substantial
battery drain on affected systems.
To fix the problem, use the maximum alarm time offset as reported by RTC
drivers to set the maximum alarm time. While this may result in early
wakeups from suspend, it is still much better than not suspending at all.
Standardize system behavior if the requested alarm timeout is larger than
the alarm timeout supported by the rtc chip. Currently, in this situation,
the RTC driver will do one of the following:
- It may return an error.
- It may limit the alarm timeout to the maximum supported by the rtc chip.
- It may mask the timeout by the maximum alarm timeout supported by the RTC
chip (i.e. a requested timeout of 1 day + 1 minute may result in a 1
minute timeout).
With this in place, if the RTC driver reports the maximum alarm timeout
supported by the RTC chip, the system will always limit the alarm timeout
to the maximum supported by the RTC chip.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/20230915152238.1144706-3-linux@roeck-us.net
|
||
|
Ingo Molnar
|
6c77437735 |
tick/nohz: Update comments some more
Inspired by recent enhancements to comments in kernel/time/tick-sched.c,
go through the entire file and fix/unify its comments:
- Fix over a dozen typos, spelling mistakes & cases of bad grammar.
- Re-phrase sentences that I needed to read three times to understand.
[ I used the following arbitrary rule-of-thumb:
- if I had to read a comment twice, it was usually my fault,
- if I had to read it a third time, it was the comment's fault. ]
- Comma updates:
- Add commas where needed
- Remove commas where not needed
- In cases where a comma is optional, choose one variant and try to
standardize it over similar sentences in the file.
- Standardize on standalone 'NOHZ' spelling in free-flowing comments:
s/nohz/NOHZ
s/no idle tick/NOHZ
Still keep 'dynticks' as a popular synonym.
- Standardize on referring to variable names within free-flowing
comments with the "'var'" nomenclature, and function names as
"function_name()".
- Standardize on '64-bit' and '32-bit':
s/32bit/32-bit
s/64bit/64-bit
- Standardize on 'IRQ work':
s/irq work/IRQ work
- A few other tidyups I probably missed to list.
No change in functionality intended - other than one small change to
a syslog output string.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/ZRVCNeMcSQcXS36N@gmail.com
|
||
|
Frederic Weisbecker
|
4f7f4409af |
tick/nohz: Don't shutdown the lowres tick from itself
In lowres dynticks mode, just like in highres dynticks mode, when there is no tick to program in the future, the tick eventually gets deactivated either: * From the idle loop if in idle mode. * From the IRQ exit if in full dynticks mode. Therefore there is no need to deactivate it from the tick itself. This just just brings more overhead in the idle tick path for no reason. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20230912104406.312185-4-frederic@kernel.org |
||
|
Frederic Weisbecker
|
822deeed3a |
tick/nohz: Update obsolete comments
Some comments are obsolete enough to assume that IRQ exit restarts the tick in idle or RCU is turned on at the same time as the tick, among other details. Update them and add more. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230912104406.312185-3-frederic@kernel.org |
||
|
Frederic Weisbecker
|
dba428a678 |
tick/nohz: Rename the tick handlers to more self-explanatory names
The current names of the tick handlers don't tell much about what different between them. Use names that better reflect their role and resolution. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230912104406.312185-2-frederic@kernel.org |
||
|
Linus Torvalds
|
a6216978de |
Fix false positive "softirq work is pending" messages on -rt
kernels, caused by a buggy factoring-out of existing code. Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmTzC5oRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1hG1Q/+ICGbpxdQOrVg7QTLzgsxttxIyi4Un6lb vPX8NO9/4HIxObR6bd+ji2499TIO6nIhRqGOzEYUe9jzEN27eM/bMo6kCcRkbWra 4V/GZd3j+XdJwIQR442cBdUcByk4X7FlE7KqizJIbvYYyLBXzboBcpOdH012e2O9 UzFjtU+pk5Lhit18jL6/AvjsMhneKb6YUH20Wbb6zjZ1FL28YGKpeOHrh6GSXlKE GVS07pWSAB8TMXdO+8YaKoE7VIOdMaYS/mJJ6u/M8Wo+Kl0wWwmJtjmSYzvD2Uod PGcCiGXr1QpWK66wZNnXjs3rb6bX5umCo8rc5L6rqvWTYvB8Owpl5V94+87yGEov 29lYvWdVJ7dPqP8fSQfYxBKbgfINwOO1STYnIX1Q5mDD9fK2SgOpD9+JFagYnJoI 5n6KoVArVHQXSB4odTn+Qyt0yu0iDubUFRxBTrWijq5ooHOExaxByl0ViyCfp1aS csTcGQSJsvHKhZPejDggjp74IU/ge5lUN4uSFlPVo3jYFwUIIgBG+43QtFiVrplg 3ifpI2qNISQl65PRerZjB5jBmItUGnUl71tnEg/Cli7zvvw/nMeKh98vChtE9S3A 2eQ66rrV9eJAeYaNCV4Uz1UmocD4i2Vec9tZOUUoIga/bDIOVr+bxUr7nvcOneak 98h2ylU4W8o= =zpfn -----END PGP SIGNATURE----- Merge tag 'timers-urgent-2023-09-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Ingo Molnar: "Fix false positive 'softirq work is pending' messages on -rt kernels, caused by a buggy factoring-out of existing code" * tag 'timers-urgent-2023-09-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/rcu: Fix false positive "softirq work is pending" messages |
||
|
Linus Torvalds
|
cd99b9eb4b |
Documentation work keeps chugging along; stuff for 6.6 includes:
- Work from Carlos Bilbao to integrate rustdoc output into the generated
HTML documentation. This took some work to figure out how to do it
without slowing the docs build and without creating people who don't have
Rust installed, but Carlos got there.
- Move the loongarch and mips architecture documentation under
Documentation/arch/.
- Some more maintainer documentation from Jakub
...plus the usual assortment of updates, translations, and fixes.
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Merge tag 'docs-6.6' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"Documentation work keeps chugging along; this includes:
- Work from Carlos Bilbao to integrate rustdoc output into the
generated HTML documentation. This took some work to figure out how
to do it without slowing the docs build and without creating people
who don't have Rust installed, but Carlos got there
- Move the loongarch and mips architecture documentation under
Documentation/arch/
- Some more maintainer documentation from Jakub
... plus the usual assortment of updates, translations, and fixes"
* tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits)
Docu: genericirq.rst: fix irq-example
input: docs: pxrc: remove reference to phoenix-sim
Documentation: serial-console: Fix literal block marker
docs/mm: remove references to hmm_mirror ops and clean typos
docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add()
Documentation: Fix typos
Documentation/ABI: Fix typos
scripts: kernel-doc: fix macro handling in enums
scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN]
Documentation: riscv: Update boot image header since EFI stub is supported
Documentation: riscv: Add early boot document
Documentation: arm: Add bootargs to the table of added DT parameters
docs: kernel-parameters: Refer to the correct bitmap function
doc: update params of memhp_default_state=
docs: Add book to process/kernel-docs.rst
docs: sparse: fix invalid link addresses
docs: vfs: clean up after the iterate() removal
docs: Add a section on surveys to the researcher guidelines
docs: move mips under arch
docs: move loongarch under arch
...
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Paul Gortmaker
|
96c1fa04f0 |
tick/rcu: Fix false positive "softirq work is pending" messages
In commit |
||
|
Linus Torvalds
|
815c24a085 |
linux-kselftest-kunit-6.6-rc1
This kunit update for Linux 6.6.rc1 consists of:
-- Adds support for running Rust documentation tests as KUnit tests
-- Makes init, str, sync, types doctests compilable/testable
-- Adds support for attributes API which include speed, modules
attributes, ability to filter and report attributes.
-- Adds support for marking tests slow using attributes API.
-- Adds attributes API documentation
-- Fixes to wild-memory-access bug in kunit_filter_suites() and
a possible memory leak in kunit_filter_suites()
-- Adds support for counting number of test suites in a module, list
action to kunit test modules, and test filtering on module tests.
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Merge tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull kunit updates from Shuah Khan:
- add support for running Rust documentation tests as KUnit tests
- make init, str, sync, types doctests compilable/testable
- add support for attributes API which include speed, modules
attributes, ability to filter and report attributes
- add support for marking tests slow using attributes API
- add attributes API documentation
- fix a wild-memory-access bug in kunit_filter_suites() and a possible
memory leak in kunit_filter_suites()
- add support for counting number of test suites in a module, list
action to kunit test modules, and test filtering on module tests
* tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
kunit: fix struct kunit_attr header
kunit: replace KUNIT_TRIGGER_STATIC_STUB maro with KUNIT_STATIC_STUB_REDIRECT
kunit: Allow kunit test modules to use test filtering
kunit: Make 'list' action available to kunit test modules
kunit: Report the count of test suites in a module
kunit: fix uninitialized variables bug in attributes filtering
kunit: fix possible memory leak in kunit_filter_suites()
kunit: fix wild-memory-access bug in kunit_filter_suites()
kunit: Add documentation of KUnit test attributes
kunit: add tests for filtering attributes
kunit: time: Mark test as slow using test attributes
kunit: memcpy: Mark tests as slow using test attributes
kunit: tool: Add command line interface to filter and report attributes
kunit: Add ability to filter attributes
kunit: Add module attribute
kunit: Add speed attribute
kunit: Add test attributes API structure
MAINTAINERS: add Rust KUnit files to the KUnit entry
rust: support running Rust documentation tests as KUnit ones
rust: types: make doctests compilable/testable
...
|
||
|
Rae Moar
|
a547c4ce10 |
kunit: time: Mark test as slow using test attributes
Mark the time KUnit test, time64_to_tm_test_date_range, as slow using test attributes. This test ran relatively much slower than most other KUnit tests. By marking this test as slow, the test can now be filtered using the KUnit test attribute filtering feature. Example: --filter "speed>slow". This will run only the tests that have speeds faster than slow. The slow attribute will also be outputted in KTAP. Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Rae Moar <rmoar@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> |
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|
Paul E. McKenney
|
e40806e9bc |
clocksource: Handle negative skews in "skew is too large" messages
The nanosecond-to-millisecond skew computation uses unsigned arithmetic,
which produces user-unfriendly large positive numbers for negative skews.
Therefore, use signed arithmetic for this computation in order to preserve
the negativity.
Reported-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Reported-by: Feng Tang <feng.tang@intel.com>
Fixes:
|
||
|
Randy Dunlap
|
67b3f564cb |
time: add kernel-doc in time.c
Add kernel-doc for all APIs that do not already have it. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: John Stultz <jstultz@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Acked-by: John Stultz <jstultz@google.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230704052405.5089-3-rdunlap@infradead.org |
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|
Linus Torvalds
|
582c161cf3 |
hardening updates for v6.5-rc1
- Fix KMSAN vs FORTIFY in strlcpy/strlcat (Alexander Potapenko) - Convert strreplace() to return string start (Andy Shevchenko) - Flexible array conversions (Arnd Bergmann, Wyes Karny, Kees Cook) - Add missing function prototypes seen with W=1 (Arnd Bergmann) - Fix strscpy() kerndoc typo (Arne Welzel) - Replace strlcpy() with strscpy() across many subsystems which were either Acked by respective maintainers or were trivial changes that went ignored for multiple weeks (Azeem Shaikh) - Remove unneeded cc-option test for UBSAN_TRAP (Nick Desaulniers) - Add KUnit tests for strcat()-family - Enable KUnit tests of FORTIFY wrappers under UML - Add more complete FORTIFY protections for strlcat() - Add missed disabling of FORTIFY for all arch purgatories. - Enable -fstrict-flex-arrays=3 globally - Tightening UBSAN_BOUNDS when using GCC - Improve checkpatch to check for strcpy, strncpy, and fake flex arrays - Improve use of const variables in FORTIFY - Add requested struct_size_t() helper for types not pointers - Add __counted_by macro for annotating flexible array size members -----BEGIN PGP SIGNATURE----- iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmSbftQWHGtlZXNjb29r QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJj0MD/9X9jzJzCmsAU+yNldeoAzC84Sk GVU3RBxGcTNysL1gZXynkIgigw7DWc4htMGeSABHHwQRVP65JCH1Kw/VqIkyumbx 9LdX6IklMJb4pRT4PVU3azebV4eNmSjlur2UxMeW54Czm91/6I8RHbJOyAPnOUmo 2oomGdP/hpEHtKR7hgy8Axc6w5ySwQixh2V5sVZG3VbvCS5WKTmTXbs6puuRT5hz iHt7v+7VtEg/Qf1W7J2oxfoghvVBsaRrSLrExWT/oZYh1ZxM7DsCAAoG/IsDgHGA 9LBXiRECgAFThbHVxLvvKZQMXdVk0i8iXLX43XMKC0wTA+NTyH7wlcQQ4RWNMuo8 sfA9Qm9gMArXaf64aymr3Uwn20Zan0391HdlbhOJZAE6v3PPJbleUnM58AzD2d3r 5Lz6AIFBxDImy+3f9iDWgacCT5/PkeiXTHzk9QnKhJyKKtRA58XJxj4q2+rPnGJP n4haXqoxD5FJbxdXiGKk31RS0U5HBug7wkOcUrTqDHUbc/QNU2b7dxTKUx+zYtCU uV5emPzpF4H4z+91WpO47n9gkMAfwV0lt9S2dwS8pxsgqctbmIan+Jgip7rsqZ2G OgLXBsb43eEs+6WgO8tVt/ZHYj9ivGMdrcNcsIfikzNs/xweUJ53k2xSEn2xEa5J cwANDmkL6QQK7yfeeg== =s0j1 -----END PGP SIGNATURE----- Merge tag 'hardening-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull hardening updates from Kees Cook: "There are three areas of note: A bunch of strlcpy()->strscpy() conversions ended up living in my tree since they were either Acked by maintainers for me to carry, or got ignored for multiple weeks (and were trivial changes). The compiler option '-fstrict-flex-arrays=3' has been enabled globally, and has been in -next for the entire devel cycle. This changes compiler diagnostics (though mainly just -Warray-bounds which is disabled) and potential UBSAN_BOUNDS and FORTIFY _warning_ coverage. In other words, there are no new restrictions, just potentially new warnings. Any new FORTIFY warnings we've seen have been fixed (usually in their respective subsystem trees). For more details, see commit |
||
|
Linus Torvalds
|
ed3b7923a8 |
Scheduler changes for v6.5:
- Scheduler SMP load-balancer improvements:
- Avoid unnecessary migrations within SMT domains on hybrid systems.
Problem:
On hybrid CPU systems, (processors with a mixture of higher-frequency
SMT cores and lower-frequency non-SMT cores), under the old code
lower-priority CPUs pulled tasks from the higher-priority cores if
more than one SMT sibling was busy - resulting in many unnecessary
task migrations.
Solution:
The new code improves the load balancer to recognize SMT cores with more
than one busy sibling and allows lower-priority CPUs to pull tasks, which
avoids superfluous migrations and lets lower-priority cores inspect all SMT
siblings for the busiest queue.
- Implement the 'runnable boosting' feature in the EAS balancer: consider CPU
contention in frequency, EAS max util & load-balance busiest CPU selection.
This improves CPU utilization for certain workloads, while leaves other key
workloads unchanged.
- Scheduler infrastructure improvements:
- Rewrite the scheduler topology setup code by consolidating it
into the build_sched_topology() helper function and building
it dynamically on the fly.
- Resolve the local_clock() vs. noinstr complications by rewriting
the code: provide separate sched_clock_noinstr() and
local_clock_noinstr() functions to be used in instrumentation code,
and make sure it is all instrumentation-safe.
- Fixes:
- Fix a kthread_park() race with wait_woken()
- Fix misc wait_task_inactive() bugs unearthed by the -rt merge:
- Fix UP PREEMPT bug by unifying the SMP and UP implementations.
- Fix task_struct::saved_state handling.
- Fix various rq clock update bugs, unearthed by turning on the rq clock
debugging code.
- Fix the PSI WINDOW_MIN_US trigger limit, which was easy to trigger by
creating enough cgroups, by removing the warnign and restricting
window size triggers to PSI file write-permission or CAP_SYS_RESOURCE.
- Propagate SMT flags in the topology when removing degenerate domain
- Fix grub_reclaim() calculation bug in the deadline scheduler code
- Avoid resetting the min update period when it is unnecessary, in
psi_trigger_destroy().
- Don't balance a task to its current running CPU in load_balance(),
which was possible on certain NUMA topologies with overlapping
groups.
- Fix the sched-debug printing of rq->nr_uninterruptible
- Cleanups:
- Address various -Wmissing-prototype warnings, as a preparation
to (maybe) enable this warning in the future.
- Remove unused code
- Mark more functions __init
- Fix shadow-variable warnings
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Scheduler SMP load-balancer improvements:
- Avoid unnecessary migrations within SMT domains on hybrid systems.
Problem:
On hybrid CPU systems, (processors with a mixture of
higher-frequency SMT cores and lower-frequency non-SMT cores),
under the old code lower-priority CPUs pulled tasks from the
higher-priority cores if more than one SMT sibling was busy -
resulting in many unnecessary task migrations.
Solution:
The new code improves the load balancer to recognize SMT cores
with more than one busy sibling and allows lower-priority CPUs
to pull tasks, which avoids superfluous migrations and lets
lower-priority cores inspect all SMT siblings for the busiest
queue.
- Implement the 'runnable boosting' feature in the EAS balancer:
consider CPU contention in frequency, EAS max util & load-balance
busiest CPU selection.
This improves CPU utilization for certain workloads, while leaves
other key workloads unchanged.
Scheduler infrastructure improvements:
- Rewrite the scheduler topology setup code by consolidating it into
the build_sched_topology() helper function and building it
dynamically on the fly.
- Resolve the local_clock() vs. noinstr complications by rewriting
the code: provide separate sched_clock_noinstr() and
local_clock_noinstr() functions to be used in instrumentation code,
and make sure it is all instrumentation-safe.
Fixes:
- Fix a kthread_park() race with wait_woken()
- Fix misc wait_task_inactive() bugs unearthed by the -rt merge:
- Fix UP PREEMPT bug by unifying the SMP and UP implementations
- Fix task_struct::saved_state handling
- Fix various rq clock update bugs, unearthed by turning on the rq
clock debugging code.
- Fix the PSI WINDOW_MIN_US trigger limit, which was easy to trigger
by creating enough cgroups, by removing the warnign and restricting
window size triggers to PSI file write-permission or
CAP_SYS_RESOURCE.
- Propagate SMT flags in the topology when removing degenerate domain
- Fix grub_reclaim() calculation bug in the deadline scheduler code
- Avoid resetting the min update period when it is unnecessary, in
psi_trigger_destroy().
- Don't balance a task to its current running CPU in load_balance(),
which was possible on certain NUMA topologies with overlapping
groups.
- Fix the sched-debug printing of rq->nr_uninterruptible
Cleanups:
- Address various -Wmissing-prototype warnings, as a preparation to
(maybe) enable this warning in the future.
- Remove unused code
- Mark more functions __init
- Fix shadow-variable warnings"
* tag 'sched-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
sched/core: Avoid multiple calling update_rq_clock() in __cfsb_csd_unthrottle()
sched/core: Avoid double calling update_rq_clock() in __balance_push_cpu_stop()
sched/core: Fixed missing rq clock update before calling set_rq_offline()
sched/deadline: Update GRUB description in the documentation
sched/deadline: Fix bandwidth reclaim equation in GRUB
sched/wait: Fix a kthread_park race with wait_woken()
sched/topology: Mark set_sched_topology() __init
sched/fair: Rename variable cpu_util eff_util
arm64/arch_timer: Fix MMIO byteswap
sched/fair, cpufreq: Introduce 'runnable boosting'
sched/fair: Refactor CPU utilization functions
cpuidle: Use local_clock_noinstr()
sched/clock: Provide local_clock_noinstr()
x86/tsc: Provide sched_clock_noinstr()
clocksource: hyper-v: Provide noinstr sched_clock()
clocksource: hyper-v: Adjust hv_read_tsc_page_tsc() to avoid special casing U64_MAX
x86/vdso: Fix gettimeofday masking
math64: Always inline u128 version of mul_u64_u64_shr()
s390/time: Provide sched_clock_noinstr()
loongarch: Provide noinstr sched_clock_read()
...
|
||
|
Linus Torvalds
|
cd336f6562 |
Time, timekeeping and related device driver updates:
- Core:
- A set of fixes, cleanups and enhancements to the posix timer code:
- Prevent another possible live lock scenario in the exit() path,
which affects POSIX_CPU_TIMERS_TASK_WORK enabled architectures.
- Fix a loop termination issue which was reported syzcaller/KSAN in
the posix timer ID allocation code.
That triggered a deeper look into the posix-timer code which
unearthed more small issues.
- Add missing READ/WRITE_ONCE() annotations
- Fix or remove completely outdated comments
- Document places which are subtle and completely undocumented.
- Add missing hrtimer modes to the trace event decoder
- Small cleanups and enhancements all over the place
- Drivers:
- Rework the Hyper-V clocksource and sched clock setup code
- Remove a deprecated clocksource driver
- Small fixes and enhancements all over the place
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Merge tag 'timers-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"Time, timekeeping and related device driver updates:
Core:
- A set of fixes, cleanups and enhancements to the posix timer code:
- Prevent another possible live lock scenario in the exit() path,
which affects POSIX_CPU_TIMERS_TASK_WORK enabled architectures.
- Fix a loop termination issue which was reported syzcaller/KSAN
in the posix timer ID allocation code.
That triggered a deeper look into the posix-timer code which
unearthed more small issues.
- Add missing READ/WRITE_ONCE() annotations
- Fix or remove completely outdated comments
- Document places which are subtle and completely undocumented.
- Add missing hrtimer modes to the trace event decoder
- Small cleanups and enhancements all over the place
Drivers:
- Rework the Hyper-V clocksource and sched clock setup code
- Remove a deprecated clocksource driver
- Small fixes and enhancements all over the place"
* tag 'timers-core-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
clocksource/drivers/cadence-ttc: Fix memory leak in ttc_timer_probe
dt-bindings: timers: Add Ralink SoCs timer
clocksource/drivers/hyper-v: Rework clocksource and sched clock setup
dt-bindings: timer: brcm,kona-timer: convert to YAML
clocksource/drivers/imx-gpt: Fold <soc/imx/timer.h> into its only user
clk: imx: Drop inclusion of unused header <soc/imx/timer.h>
hrtimer: Add missing sparse annotations to hrtimer locking
clocksource/drivers/imx-gpt: Use only a single name for functions
clocksource/drivers/loongson1: Move PWM timer to clocksource framework
dt-bindings: timer: Add Loongson-1 clocksource
MIPS: Loongson32: Remove deprecated PWM timer clocksource
clocksource/drivers/ingenic-timer: Use pm_sleep_ptr() macro
tracing/timer: Add missing hrtimer modes to decode_hrtimer_mode().
posix-timers: Add sys_ni_posix_timers() prototype
tick/rcu: Fix bogus ratelimit condition
alarmtimer: Remove unnecessary (void *) cast
alarmtimer: Remove unnecessary initialization of variable 'ret'
posix-timers: Refer properly to CONFIG_HIGH_RES_TIMERS
posix-timers: Polish coding style in a few places
posix-timers: Remove pointless comments
...
|
||
|
Ben Dooks
|
ccaa4926c2 |
hrtimer: Add missing sparse annotations to hrtimer locking
Sparse warns about lock imbalance vs. the hrtimer_base lock due to missing sparse annotations: kernel/time/hrtimer.c:175:33: warning: context imbalance in 'lock_hrtimer_base' - wrong count at exit kernel/time/hrtimer.c:1301:28: warning: context imbalance in 'hrtimer_start_range_ns' - unexpected unlock kernel/time/hrtimer.c:1336:28: warning: context imbalance in 'hrtimer_try_to_cancel' - unexpected unlock kernel/time/hrtimer.c:1457:9: warning: context imbalance in '__hrtimer_get_remaining' - unexpected unlock Add the annotations to the relevant functions. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230621075928.394481-1-ben.dooks@codethink.co.uk |
||
|
Wen Yang
|
a7e282c777 |
tick/rcu: Fix bogus ratelimit condition
The ratelimit logic in report_idle_softirq() is broken because the
exit condition is always true:
static int ratelimit;
if (ratelimit < 10)
return false; ---> always returns here
ratelimit++; ---> no chance to run
Make it check for >= 10 instead.
Fixes:
|
||
|
Li zeming
|
fc4b4d96f7 |
alarmtimer: Remove unnecessary (void *) cast
Pointers of type void * do not require a type cast when they are assigned to a real pointer. Signed-off-by: Li zeming <zeming@nfschina.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230609182059.4509-1-zeming@nfschina.com |
||
|
Li zeming
|
986af8dc5a |
alarmtimer: Remove unnecessary initialization of variable 'ret'
ret is assigned before checked, so it does not need to initialize the variable Signed-off-by: Li zeming <zeming@nfschina.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230609182856.4660-1-zeming@nfschina.com |
||
|
Lukas Bulwahn
|
b9a40f24d8 |
posix-timers: Refer properly to CONFIG_HIGH_RES_TIMERS
Commit c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
turns an ifdef CONFIG_HIGH_RES_TIMERS into an conditional on
"IS_ENABLED(CONFIG_HIGHRES_TIMERS)"; note that the new conditional refers
to "HIGHRES_TIMERS" not "HIGH_RES_TIMERS" as before.
Fix this typo introduced in that refactoring.
Fixes: c78f261e5dcb ("posix-timers: Clarify posix_timer_fn() comments")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230609094643.26253-1-lukas.bulwahn@gmail.com
|
||
|
Thomas Gleixner
|
b96ce4931f |
posix-timers: Polish coding style in a few places
Make it consistent with the TIP tree documentation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.888493625@linutronix.de |
||
|
Thomas Gleixner
|
200dbd6d14 |
posix-timers: Remove pointless comments
Documenting the obvious is just consuming space for no value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.832240451@linutronix.de |
||
|
Thomas Gleixner
|
84999b8bdb |
posix-timers: Clarify posix_timer_fn() comments
Make the issues vs. SIG_IGN understandable and remove the 15 years old promise that a proper solution is already on the horizon. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/874jnrdmrq.ffs@tglx |
||
|
Thomas Gleixner
|
02972d7955 |
posix-timers: Clarify posix_timer_rearm() comment
Yet another incomprehensible piece of art. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.724863461@linutronix.de |
||
|
Thomas Gleixner
|
c575689d66 |
posix-timers: Comment SIGEV_THREAD_ID properly
Replace the word salad. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.672220780@linutronix.de |
||
|
Thomas Gleixner
|
52f090b164 |
posix-timers: Add proper comments in do_timer_create()
The comment about timer lifetime at the end of the function is misplaced and uncomprehensible. Make it understandable and put it at the right place. Add a new comment about the visibility of the new timer ID to user space. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.619897296@linutronix.de |
||
|
Thomas Gleixner
|
640fe745d7 |
posix-timers: Document nanosleep() details
The descriptions for common_nsleep() is wrong and common_nsleep_timens() lacks any form of comment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.567072835@linutronix.de |
||
|
Thomas Gleixner
|
3561fcb402 |
posix-timers: Document sys_clock_settime() permissions in place
The documentation of sys_clock_settime() permissions is at a random place and mostly word salad. Remove it and add a concise comment into sys_clock_settime(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.514700292@linutronix.de |
||
|
Thomas Gleixner
|
65cade468d |
posix-timers: Document sys_clock_getoverrun()
Document the syscall in detail and with coherent sentences. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.462051641@linutronix.de |
||
|
Thomas Gleixner
|
a86e928433 |
posix-timers: Document common_clock_get() correctly
Replace another confusing and inaccurate set of comments. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.409169321@linutronix.de |
||
|
Thomas Gleixner
|
01679b5db7 |
posix-timers: Document sys_clock_getres() correctly
The decades old comment about Posix clock resolution is confusing at best. Remove it and add a proper explanation to sys_clock_getres(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.356427330@linutronix.de |
||
|
Thomas Gleixner
|
8cc96ca2c7 |
posix-timers: Split release_posix_timers()
release_posix_timers() is called for cleaning up both hashed and unhashed timers. The cases are differentiated by an argument and the usage is hideous. Seperate the actual free path out and use it for unhashed timers. Provide a function for hashed timers. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.301432503@linutronix.de |
||
|
Thomas Gleixner
|
11fbe6cd41 |
posix-timers: Remove pointless irqsafe from hash_lock
All usage of hash_lock is in thread context. No point in using spin_lock_irqsave()/irqrestore() for a single usage site. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.249063953@linutronix.de |
||
|
Thomas Gleixner
|
72786ff23d |
posix-timers: Set k_itimer:: It_signal to NULL on exit()
Technically it's not required to set k_itimer::it_signal to NULL on exit() because there is no other thread anymore which could lookup the timer concurrently. Set it to NULL for consistency sake and add a comment to that effect. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.196462644@linutronix.de |
||
|
Thomas Gleixner
|
028cf5eaa1 |
posix-timers: Annotate concurrent access to k_itimer:: It_signal
k_itimer::it_signal is read lockless in the RCU protected hash lookup, but it can be written concurrently in the timer_create() and timer_delete() path. Annotate these places with READ_ONCE() and WRITE_ONCE() Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.143596887@linutronix.de |
||
|
Thomas Gleixner
|
ae88967d71 |
posix-timers: Add comments about timer lookup
Document how the timer ID validation in the hash table works. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.091081515@linutronix.de |
||
|
Thomas Gleixner
|
8d44b958a1 |
posix-timers: Cleanup comments about timer ID tracking
Describe the hash table properly and remove the IDR leftover comments. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183313.038444551@linutronix.de |
||
|
Thomas Gleixner
|
7d99090266 |
posix-timers: Clarify timer_wait_running() comment
Explain it better and add the CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y aspect for completeness. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230425183312.985681995@linutronix.de |
||
|
Thomas Gleixner
|
8ce8849dd1 |
posix-timers: Ensure timer ID search-loop limit is valid
posix_timer_add() tries to allocate a posix timer ID by starting from the
cached ID which was stored by the last successful allocation.
This is done in a loop searching the ID space for a free slot one by
one. The loop has to terminate when the search wrapped around to the
starting point.
But that's racy vs. establishing the starting point. That is read out
lockless, which leads to the following problem:
CPU0 CPU1
posix_timer_add()
start = sig->posix_timer_id;
lock(hash_lock);
... posix_timer_add()
if (++sig->posix_timer_id < 0)
start = sig->posix_timer_id;
sig->posix_timer_id = 0;
So CPU1 can observe a negative start value, i.e. -1, and the loop break
never happens because the condition can never be true:
if (sig->posix_timer_id == start)
break;
While this is unlikely to ever turn into an endless loop as the ID space is
huge (INT_MAX), the racy read of the start value caught the attention of
KCSAN and Dmitry unearthed that incorrectness.
Rewrite it so that all id operations are under the hash lock.
Reported-by: syzbot+5c54bd3eb218bb595aa9@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/87bkhzdn6g.ffs@tglx
|
||
|
Thomas Gleixner
|
9d9e522010 |
posix-timers: Prevent RT livelock in itimer_delete()
itimer_delete() has a retry loop when the timer is concurrently expired. On
non-RT kernels this just spin-waits until the timer callback has completed,
except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK
enabled.
In that case and on RT kernels the existing task could live lock when
preempting the task which does the timer delivery.
Replace spin_unlock() with an invocation of timer_wait_running() to handle
it the same way as the other retry loops in the posix timer code.
Fixes:
|
||
|
Thomas Gleixner
|
13bb06f8dd |
tick/common: Align tick period during sched_timer setup
The tick period is aligned very early while the first clock_event_device is
registered. At that point the system runs in periodic mode and switches
later to one-shot mode if possible.
The next wake-up event is programmed based on the aligned value
(tick_next_period) but the delta value, that is used to program the
clock_event_device, is computed based on ktime_get().
With the subtracted offset, the device fires earlier than the exact time
frame. With a large enough offset the system programs the timer for the
next wake-up and the remaining time left is too small to make any boot
progress. The system hangs.
Move the alignment later to the setup of tick_sched timer. At this point
the system switches to oneshot mode and a high resolution clocksource is
available. At this point it is safe to align tick_next_period because
ktime_get() will now return accurate (not jiffies based) time.
[bigeasy: Patch description + testing].
Fixes:
|
||
|
Peter Zijlstra
|
5949a68c73 |
time/sched_clock: Provide sched_clock_noinstr()
With the intent to provide local_clock_noinstr(), a variant of
local_clock() that's safe to be called from noinstr code (with the
assumption that any such code will already be non-preemptible),
prepare for things by providing a noinstr sched_clock_noinstr() function.
Specifically, preempt_enable_*() calls out to schedule(), which upsets
noinstr validation efforts.
As such, pull out the preempt_{dis,en}able_notrace() requirements from
the sched_clock_read() implementations by explicitly providing it in
the sched_clock() function.
This further requires said sched_clock_read() functions to be noinstr
themselves, for ARCH_WANTS_NO_INSTR users. See the next few patches.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V
Link: https://lore.kernel.org/r/20230519102715.302350330@infradead.org
|
||
|
Peter Zijlstra
|
d16317de9b |
seqlock/latch: Provide raw_read_seqcount_latch_retry()
The read side of seqcount_latch consists of:
do {
seq = raw_read_seqcount_latch(&latch->seq);
...
} while (read_seqcount_latch_retry(&latch->seq, seq));
which is asymmetric in the raw_ department, and sure enough,
read_seqcount_latch_retry() includes (explicit) instrumentation where
raw_read_seqcount_latch() does not.
This inconsistency becomes a problem when trying to use it from
noinstr code. As such, fix it by renaming and re-implementing
raw_read_seqcount_latch_retry() without the instrumentation.
Specifically the instrumentation in question is kcsan_atomic_next(0)
in do___read_seqcount_retry(). Loosing this annotation is not a
problem because raw_read_seqcount_latch() does not pass through
kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V
Link: https://lore.kernel.org/r/20230519102715.233598176@infradead.org
|
||
|
Azeem Shaikh
|
76edc27eda |
clocksource: Replace all non-returning strlcpy with strscpy
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Acked-by: John Stultz <jstultz@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230530163546.986188-1-azeemshaikh38@gmail.com |
||
|
Thomas Gleixner
|
f9d36cf445 |
tick/broadcast: Make broadcast device replacement work correctly
When a tick broadcast clockevent device is initialized for one shot mode
then tick_broadcast_setup_oneshot() OR's the periodic broadcast mode
cpumask into the oneshot broadcast cpumask.
This is required when switching from periodic broadcast mode to oneshot
broadcast mode to ensure that CPUs which are waiting for periodic
broadcast are woken up on the next tick.
But it is subtly broken, when an active broadcast device is replaced and
the system is already in oneshot (NOHZ/HIGHRES) mode. Victor observed
this and debugged the issue.
Then the OR of the periodic broadcast CPU mask is wrong as the periodic
cpumask bits are sticky after tick_broadcast_enable() set it for a CPU
unless explicitly cleared via tick_broadcast_disable().
That means that this sets all other CPUs which have tick broadcasting
enabled at that point unconditionally in the oneshot broadcast mask.
If the affected CPUs were already idle and had their bits set in the
oneshot broadcast mask then this does no harm. But for non idle CPUs
which were not set this corrupts their state.
On their next invocation of tick_broadcast_enable() they observe the bit
set, which indicates that the broadcast for the CPU is already set up.
As a consequence they fail to update the broadcast event even if their
earliest expiring timer is before the actually programmed broadcast
event.
If the programmed broadcast event is far in the future, then this can
cause stalls or trigger the hung task detector.
Avoid this by telling tick_broadcast_setup_oneshot() explicitly whether
this is the initial switch over from periodic to oneshot broadcast which
must take the periodic broadcast mask into account. In the case of
initialization of a replacement device this prevents that the broadcast
oneshot mask is modified.
There is a second problem with broadcast device replacement in this
function. The broadcast device is only armed when the previous state of
the device was periodic.
That is correct for the switch from periodic broadcast mode to oneshot
broadcast mode as the underlying broadcast device could operate in
oneshot state already due to lack of periodic state in hardware. In that
case it is already armed to expire at the next tick.
For the replacement case this is wrong as the device is in shutdown
state. That means that any already pending broadcast event will not be
armed.
This went unnoticed because any CPU which goes idle will observe that
the broadcast device has an expiry time of KTIME_MAX and therefore any
CPUs next timer event will be earlier and cause a reprogramming of the
broadcast device. But that does not guarantee that the events of the
CPUs which were already in idle are delivered on time.
Fix this by arming the newly installed device for an immediate event
which will reevaluate the per CPU expiry times and reprogram the
broadcast device accordingly. This is simpler than caching the last
expiry time in yet another place or saving it before the device exchange
and handing it down to the setup function. Replacement of broadcast
devices is not a frequent operation and usually happens once somewhere
late in the boot process.
Fixes:
|
||
|
Linus Torvalds
|
7d8d20191c |
Timekeeping and clocksource/event driver updates the second batch:
- A trivial documentation fix in the timekeeping core
- A really boring set of small fixes, enhancements and cleanups in the
drivers code. No new clocksource/clockevent drivers for a change.
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Merge tag 'timers-core-2023-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more timer updates from Thomas Gleixner:
"Timekeeping and clocksource/event driver updates the second batch:
- A trivial documentation fix in the timekeeping core
- A really boring set of small fixes, enhancements and cleanups in
the drivers code. No new clocksource/clockevent drivers for a
change"
* tag 'timers-core-2023-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Fix references to nonexistent ktime_get_fast_ns()
dt-bindings: timer: rockchip: Add rk3588 compatible
dt-bindings: timer: rockchip: Drop superfluous rk3288 compatible
clocksource/drivers/ti: Use of_property_read_bool() for boolean properties
clocksource/drivers/timer-ti-dm: Fix finding alwon timer
clocksource/drivers/davinci: Fix memory leak in davinci_timer_register when init fails
clocksource/drivers/stm32-lp: Drop of_match_ptr for ID table
clocksource/drivers/timer-ti-dm: Convert to platform remove callback returning void
clocksource/drivers/timer-tegra186: Convert to platform remove callback returning void
clocksource/drivers/timer-ti-dm: Improve error message in .remove
clocksource/drivers/timer-stm32-lp: Mark driver as non-removable
clocksource/drivers/sh_mtu2: Mark driver as non-removable
clocksource/drivers/timer-ti-dm: Use of_address_to_resource()
clocksource/drivers/timer-imx-gpt: Remove non-DT function
clocksource/drivers/timer-mediatek: Split out CPUXGPT timers
clocksource/drivers/exynos_mct: Explicitly return 0 for shared timer
|
||
|
Linus Torvalds
|
556eb8b791 |
Driver core changes for 6.4-rc1
Here is the large set of driver core changes for 6.4-rc1. Once again, a busy development cycle, with lots of changes happening in the driver core in the quest to be able to move "struct bus" and "struct class" into read-only memory, a task now complete with these changes. This will make the future rust interactions with the driver core more "provably correct" as well as providing more obvious lifetime rules for all busses and classes in the kernel. The changes required for this did touch many individual classes and busses as many callbacks were changed to take const * parameters instead. All of these changes have been submitted to the various subsystem maintainers, giving them plenty of time to review, and most of them actually did so. Other than those changes, included in here are a small set of other things: - kobject logging improvements - cacheinfo improvements and updates - obligatory fw_devlink updates and fixes - documentation updates - device property cleanups and const * changes - firwmare loader dependency fixes. All of these have been in linux-next for a while with no reported problems. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZEp7Sw8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ykitQCfamUHpxGcKOAGuLXMotXNakTEsxgAoIquENm5 LEGadNS38k5fs+73UaxV =7K4B -----END PGP SIGNATURE----- Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the large set of driver core changes for 6.4-rc1. Once again, a busy development cycle, with lots of changes happening in the driver core in the quest to be able to move "struct bus" and "struct class" into read-only memory, a task now complete with these changes. This will make the future rust interactions with the driver core more "provably correct" as well as providing more obvious lifetime rules for all busses and classes in the kernel. The changes required for this did touch many individual classes and busses as many callbacks were changed to take const * parameters instead. All of these changes have been submitted to the various subsystem maintainers, giving them plenty of time to review, and most of them actually did so. Other than those changes, included in here are a small set of other things: - kobject logging improvements - cacheinfo improvements and updates - obligatory fw_devlink updates and fixes - documentation updates - device property cleanups and const * changes - firwmare loader dependency fixes. All of these have been in linux-next for a while with no reported problems" * tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits) device property: make device_property functions take const device * driver core: update comments in device_rename() driver core: Don't require dynamic_debug for initcall_debug probe timing firmware_loader: rework crypto dependencies firmware_loader: Strip off \n from customized path zram: fix up permission for the hot_add sysfs file cacheinfo: Add use_arch[|_cache]_info field/function arch_topology: Remove early cacheinfo error message if -ENOENT cacheinfo: Check cache properties are present in DT cacheinfo: Check sib_leaf in cache_leaves_are_shared() cacheinfo: Allow early level detection when DT/ACPI info is missing/broken cacheinfo: Add arm64 early level initializer implementation cacheinfo: Add arch specific early level initializer tty: make tty_class a static const structure driver core: class: remove struct class_interface * from callbacks driver core: class: mark the struct class in struct class_interface constant driver core: class: make class_register() take a const * driver core: class: mark class_release() as taking a const * driver core: remove incorrect comment for device_create* MIPS: vpe-cmp: remove module owner pointer from struct class usage. ... |
||
|
Geert Uytterhoeven
|
158009f1b4 |
timekeeping: Fix references to nonexistent ktime_get_fast_ns()
There was never a function named ktime_get_fast_ns().
Presumably these should refer to ktime_get_mono_fast_ns() instead.
Fixes:
|
||
|
Linus Torvalds
|
e7989789c6 |
Timers and timekeeping updates:
- Improve the VDSO build time checks to cover all dynamic relocations
VDSO does not allow dynamic relcations, but the build time check is
incomplete and fragile.
It's based on architectures specifying the relocation types to search
for and does not handle R_*_NONE relocation entries correctly.
R_*_NONE relocations are injected by some GNU ld variants if they fail
to determine the exact .rel[a]/dyn_size to cover trailing zeros.
R_*_NONE relocations must be ignored by dynamic loaders, so they
should be ignored in the build time check too.
Remove the architecture specific relocation types to check for and
validate strictly that no other relocations than R_*_NONE end up
in the VSDO .so file.
- Prefer signal delivery to the current thread for
CLOCK_PROCESS_CPUTIME_ID based posix-timers
Such timers prefer to deliver the signal to the main thread of a
process even if the context in which the timer expires is the current
task. This has the downside that it might wake up an idle thread.
As there is no requirement or guarantee that the signal has to be
delivered to the main thread, avoid this by preferring the current
task if it is part of the thread group which shares sighand.
This not only avoids waking idle threads, it also distributes the
signal delivery in case of multiple timers firing in the context
of different threads close to each other better.
- Align the tick period properly (again)
For a long time the tick was starting at CLOCK_MONOTONIC zero, which
allowed users space applications to either align with the tick or to
place a periodic computation so that it does not interfere with the
tick. The alignement of the tick period was more by chance than by
intention as the tick is set up before a high resolution clocksource is
installed, i.e. timekeeping is still tick based and the tick period
advances from there.
The early enablement of sched_clock() broke this alignement as the time
accumulated by sched_clock() is taken into account when timekeeping is
initialized. So the base value now(CLOCK_MONOTONIC) is not longer a
multiple of tick periods, which breaks applications which relied on
that behaviour.
Cure this by aligning the tick starting point to the next multiple of
tick periods, i.e 1000ms/CONFIG_HZ.
- A set of NOHZ fixes and enhancements
- Cure the concurrent writer race for idle and IO sleeptime statistics
The statitic values which are exposed via /proc/stat are updated from
the CPU local idle exit and remotely by cpufreq, but that happens
without any form of serialization. As a consequence sleeptimes can be
accounted twice or worse.
Prevent this by restricting the accumulation writeback to the CPU
local idle exit and let the remote access compute the accumulated
value.
- Protect idle/iowait sleep time with a sequence count
Reading idle/iowait sleep time, e.g. from /proc/stat, can race with
idle exit updates. As a consequence the readout may result in random
and potentially going backwards values.
Protect this by a sequence count, which fixes the idle time
statistics issue, but cannot fix the iowait time problem because
iowait time accounting races with remote wake ups decrementing the
remote runqueues nr_iowait counter. The latter is impossible to fix,
so the only way to deal with that is to document it properly and to
remove the assertion in the selftest which triggers occasionally due
to that.
- Restructure struct tick_sched for better cache layout
- Some small cleanups and a better cache layout for struct tick_sched
- Implement the missing timer_wait_running() callback for POSIX CPU timers
For unknown reason the introduction of the timer_wait_running() callback
missed to fixup posix CPU timers, which went unnoticed for almost four
years.
While initially only targeted to prevent livelocks between a timer
deletion and the timer expiry function on PREEMPT_RT enabled kernels, it
turned out that fixing this for mainline is not as trivial as just
implementing a stub similar to the hrtimer/timer callbacks.
The reason is that for CONFIG_POSIX_CPU_TIMERS_TASK_WORK enabled systems
there is a livelock issue independent of RT.
CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y moves the expiry of POSIX CPU timers
out from hard interrupt context to task work, which is handled before
returning to user space or to a VM. The expiry mechanism moves the
expired timers to a stack local list head with sighand lock held. Once
sighand is dropped the task can be preempted and a task which wants to
delete a timer will spin-wait until the expiry task is scheduled back
in. In the worst case this will end up in a livelock when the preempting
task and the expiry task are pinned on the same CPU.
The timer wheel has a timer_wait_running() mechanism for RT, which uses
a per CPU timer-base expiry lock which is held by the expiry code and the
task waiting for the timer function to complete blocks on that lock.
This does not work in the same way for posix CPU timers as there is no
timer base and expiry for process wide timers can run on any task
belonging to that process, but the concept of waiting on an expiry lock
can be used too in a slightly different way.
Add a per task mutex to struct posix_cputimers_work, let the expiry task
hold it accross the expiry function and let the deleting task which
waits for the expiry to complete block on the mutex.
In the non-contended case this results in an extra mutex_lock()/unlock()
pair on both sides.
This avoids spin-waiting on a task which is scheduled out, prevents the
livelock and cures the problem for RT and !RT systems.
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Merge tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timers and timekeeping updates from Thomas Gleixner:
- Improve the VDSO build time checks to cover all dynamic relocations
VDSO does not allow dynamic relocations, but the build time check is
incomplete and fragile.
It's based on architectures specifying the relocation types to search
for and does not handle R_*_NONE relocation entries correctly.
R_*_NONE relocations are injected by some GNU ld variants if they
fail to determine the exact .rel[a]/dyn_size to cover trailing zeros.
R_*_NONE relocations must be ignored by dynamic loaders, so they
should be ignored in the build time check too.
Remove the architecture specific relocation types to check for and
validate strictly that no other relocations than R_*_NONE end up in
the VSDO .so file.
- Prefer signal delivery to the current thread for
CLOCK_PROCESS_CPUTIME_ID based posix-timers
Such timers prefer to deliver the signal to the main thread of a
process even if the context in which the timer expires is the current
task. This has the downside that it might wake up an idle thread.
As there is no requirement or guarantee that the signal has to be
delivered to the main thread, avoid this by preferring the current
task if it is part of the thread group which shares sighand.
This not only avoids waking idle threads, it also distributes the
signal delivery in case of multiple timers firing in the context of
different threads close to each other better.
- Align the tick period properly (again)
For a long time the tick was starting at CLOCK_MONOTONIC zero, which
allowed users space applications to either align with the tick or to
place a periodic computation so that it does not interfere with the
tick. The alignement of the tick period was more by chance than by
intention as the tick is set up before a high resolution clocksource
is installed, i.e. timekeeping is still tick based and the tick
period advances from there.
The early enablement of sched_clock() broke this alignement as the
time accumulated by sched_clock() is taken into account when
timekeeping is initialized. So the base value now(CLOCK_MONOTONIC) is
not longer a multiple of tick periods, which breaks applications
which relied on that behaviour.
Cure this by aligning the tick starting point to the next multiple of
tick periods, i.e 1000ms/CONFIG_HZ.
- A set of NOHZ fixes and enhancements:
* Cure the concurrent writer race for idle and IO sleeptime
statistics
The statitic values which are exposed via /proc/stat are updated
from the CPU local idle exit and remotely by cpufreq, but that
happens without any form of serialization. As a consequence
sleeptimes can be accounted twice or worse.
Prevent this by restricting the accumulation writeback to the CPU
local idle exit and let the remote access compute the accumulated
value.
* Protect idle/iowait sleep time with a sequence count
Reading idle/iowait sleep time, e.g. from /proc/stat, can race
with idle exit updates. As a consequence the readout may result
in random and potentially going backwards values.
Protect this by a sequence count, which fixes the idle time
statistics issue, but cannot fix the iowait time problem because
iowait time accounting races with remote wake ups decrementing
the remote runqueues nr_iowait counter. The latter is impossible
to fix, so the only way to deal with that is to document it
properly and to remove the assertion in the selftest which
triggers occasionally due to that.
* Restructure struct tick_sched for better cache layout
* Some small cleanups and a better cache layout for struct
tick_sched
- Implement the missing timer_wait_running() callback for POSIX CPU
timers
For unknown reason the introduction of the timer_wait_running()
callback missed to fixup posix CPU timers, which went unnoticed for
almost four years.
While initially only targeted to prevent livelocks between a timer
deletion and the timer expiry function on PREEMPT_RT enabled kernels,
it turned out that fixing this for mainline is not as trivial as just
implementing a stub similar to the hrtimer/timer callbacks.
The reason is that for CONFIG_POSIX_CPU_TIMERS_TASK_WORK enabled
systems there is a livelock issue independent of RT.
CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y moves the expiry of POSIX CPU
timers out from hard interrupt context to task work, which is handled
before returning to user space or to a VM. The expiry mechanism moves
the expired timers to a stack local list head with sighand lock held.
Once sighand is dropped the task can be preempted and a task which
wants to delete a timer will spin-wait until the expiry task is
scheduled back in. In the worst case this will end up in a livelock
when the preempting task and the expiry task are pinned on the same
CPU.
The timer wheel has a timer_wait_running() mechanism for RT, which
uses a per CPU timer-base expiry lock which is held by the expiry
code and the task waiting for the timer function to complete blocks
on that lock.
This does not work in the same way for posix CPU timers as there is
no timer base and expiry for process wide timers can run on any task
belonging to that process, but the concept of waiting on an expiry
lock can be used too in a slightly different way.
Add a per task mutex to struct posix_cputimers_work, let the expiry
task hold it accross the expiry function and let the deleting task
which waits for the expiry to complete block on the mutex.
In the non-contended case this results in an extra
mutex_lock()/unlock() pair on both sides.
This avoids spin-waiting on a task which is scheduled out, prevents
the livelock and cures the problem for RT and !RT systems
* tag 'timers-core-2023-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-cpu-timers: Implement the missing timer_wait_running callback
selftests/proc: Assert clock_gettime(CLOCK_BOOTTIME) VS /proc/uptime monotonicity
selftests/proc: Remove idle time monotonicity assertions
MAINTAINERS: Remove stale email address
timers/nohz: Remove middle-function __tick_nohz_idle_stop_tick()
timers/nohz: Add a comment about broken iowait counter update race
timers/nohz: Protect idle/iowait sleep time under seqcount
timers/nohz: Only ever update sleeptime from idle exit
timers/nohz: Restructure and reshuffle struct tick_sched
tick/common: Align tick period with the HZ tick.
selftests/timers/posix_timers: Test delivery of signals across threads
posix-timers: Prefer delivery of signals to the current thread
vdso: Improve cmd_vdso_check to check all dynamic relocations
|
||
|
Thomas Gleixner
|
f7abf14f00 |
posix-cpu-timers: Implement the missing timer_wait_running callback
For some unknown reason the introduction of the timer_wait_running callback
missed to fixup posix CPU timers, which went unnoticed for almost four years.
Marco reported recently that the WARN_ON() in timer_wait_running()
triggers with a posix CPU timer test case.
Posix CPU timers have two execution models for expiring timers depending on
CONFIG_POSIX_CPU_TIMERS_TASK_WORK:
1) If not enabled, the expiry happens in hard interrupt context so
spin waiting on the remote CPU is reasonably time bound.
Implement an empty stub function for that case.
2) If enabled, the expiry happens in task work before returning to user
space or guest mode. The expired timers are marked as firing and moved
from the timer queue to a local list head with sighand lock held. Once
the timers are moved, sighand lock is dropped and the expiry happens in
fully preemptible context. That means the expiring task can be scheduled
out, migrated, interrupted etc. So spin waiting on it is more than
suboptimal.
The timer wheel has a timer_wait_running() mechanism for RT, which uses
a per CPU timer-base expiry lock which is held by the expiry code and the
task waiting for the timer function to complete blocks on that lock.
This does not work in the same way for posix CPU timers as there is no
timer base and expiry for process wide timers can run on any task
belonging to that process, but the concept of waiting on an expiry lock
can be used too in a slightly different way:
- Add a mutex to struct posix_cputimers_work. This struct is per task
and used to schedule the expiry task work from the timer interrupt.
- Add a task_struct pointer to struct cpu_timer which is used to store
a the task which runs the expiry. That's filled in when the task
moves the expired timers to the local expiry list. That's not
affecting the size of the k_itimer union as there are bigger union
members already
- Let the task take the expiry mutex around the expiry function
- Let the waiter acquire a task reference with rcu_read_lock() held and
block on the expiry mutex
This avoids spin-waiting on a task which might not even be on a CPU and
works nicely for RT too.
Fixes:
|
||
|
Frederic Weisbecker
|
289dafed38 |
timers/nohz: Remove middle-function __tick_nohz_idle_stop_tick()
There is no need for the __tick_nohz_idle_stop_tick() function between tick_nohz_idle_stop_tick() and its implementation. Remove that unnecessary step. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230222144649.624380-6-frederic@kernel.org |
||
|
Frederic Weisbecker
|
ead70b7523 |
timers/nohz: Add a comment about broken iowait counter update race
The per-cpu iowait task counter is incremented locally upon sleeping.
But since the task can be woken to (and by) another CPU, the counter may
then be decremented remotely. This is the source of a race involving
readers VS writer of idle/iowait sleeptime.
The following scenario shows an example where a /proc/stat reader
observes a pending sleep time as IO whereas that pending sleep time
later eventually gets accounted as non-IO.
CPU 0 CPU 1 CPU 2
----- ----- ------
//io_schedule() TASK A
current->in_iowait = 1
rq(0)->nr_iowait++
//switch to idle
// READ /proc/stat
// See nr_iowait_cpu(0) == 1
return ts->iowait_sleeptime +
ktime_sub(ktime_get(), ts->idle_entrytime)
//try_to_wake_up(TASK A)
rq(0)->nr_iowait--
//idle exit
// See nr_iowait_cpu(0) == 0
ts->idle_sleeptime += ktime_sub(ktime_get(), ts->idle_entrytime)
As a result subsequent reads on /proc/stat may expose backward progress.
This is unfortunately hardly fixable. Just add a comment about that
condition.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230222144649.624380-5-frederic@kernel.org
|
||
|
Frederic Weisbecker
|
620a30fa0b |
timers/nohz: Protect idle/iowait sleep time under seqcount
Reading idle/IO sleep time (eg: from /proc/stat) can race with idle exit updates because the state machine handling the stats is not atomic and requires a coherent read batch. As a result reading the sleep time may report irrelevant or backward values. Fix this with protecting the simple state machine within a seqcount. This is expected to be cheap enough not to add measurable performance impact on the idle path. Note this only fixes reader VS writer condition partitially. A race remains that involves remote updates of the CPU iowait task counter. It can hardly be fixed. Reported-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230222144649.624380-4-frederic@kernel.org |
||
|
Frederic Weisbecker
|
07b65a800b |
timers/nohz: Only ever update sleeptime from idle exit
The idle and IO sleeptime statistics appearing in /proc/stat can be currently updated from two sites: locally on idle exit and remotely by cpufreq. However there is no synchronization mechanism protecting concurrent updates. It is therefore possible to account the sleeptime twice, among all the other possible broken scenarios. To prevent from breaking the sleeptime accounting source, restrict the sleeptime updates to the local idle exit site. If there is a delta to add since the last update, IO/Idle sleep time readers will now only compute the delta without actually writing it back to the internal idle statistic fields. This fixes a writer VS writer race. Note there are still two known reader VS writer races to handle. A subsequent patch will fix one. Reported-by: Yu Liao <liaoyu15@huawei.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230222144649.624380-3-frederic@kernel.org |
||
|
Frederic Weisbecker
|
605da849d5 |
timers/nohz: Restructure and reshuffle struct tick_sched
Restructure and group fields by access in order to optimize cache layout. While at it, also add missing kernel doc for two fields: @last_jiffies and @idle_expires. Reported-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20230222144649.624380-2-frederic@kernel.org |
||
|
Sebastian Andrzej Siewior
|
e9523a0d81 |
tick/common: Align tick period with the HZ tick.
With HIGHRES enabled tick_sched_timer() is programmed every jiffy to
expire the timer_list timers. This timer is programmed accurate in
respect to CLOCK_MONOTONIC so that 0 seconds and nanoseconds is the
first tick and the next one is 1000/CONFIG_HZ ms later. For HZ=250 it is
every 4 ms and so based on the current time the next tick can be
computed.
This accuracy broke since the commit mentioned below because the jiffy
based clocksource is initialized with higher accuracy in
read_persistent_wall_and_boot_offset(). This higher accuracy is
inherited during the setup in tick_setup_device(). The timer still fires
every 4ms with HZ=250 but timer is no longer aligned with
CLOCK_MONOTONIC with 0 as it origin but has an offset in the us/ns part
of the timestamp. The offset differs with every boot and makes it
impossible for user land to align with the tick.
Align the tick period with CLOCK_MONOTONIC ensuring that it is always a
multiple of 1000/CONFIG_HZ ms.
Fixes:
|
||
|
Zqiang
|
db7b464df9 |
rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
This commit adds checks for the TICK_DEP_MASK_RCU_EXP bit, thus enabling
RCU expedited grace periods to actually force-enable scheduling-clock
interrupts on holdout CPUs.
Fixes:
|
||
|
Joel Fernandes (Google)
|
58d7668242 |
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
For CONFIG_NO_HZ_FULL systems, the tick_do_timer_cpu cannot be offlined.
However, cpu_is_hotpluggable() still returns true for those CPUs. This causes
torture tests that do offlining to end up trying to offline this CPU causing
test failures. Such failure happens on all architectures.
Fix the repeated error messages thrown by this (even if the hotplug errors are
harmless) by asking the opinion of the nohz subsystem on whether the CPU can be
hotplugged.
[ Apply Frederic Weisbecker feedback on refactoring tick_nohz_cpu_down(). ]
For drivers/base/ portion:
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Zhouyi Zhou <zhouzhouyi@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: rcu <rcu@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes:
|
||
|
Greg Kroah-Hartman
|
2243acd50a |
driver core: class: remove struct class_interface * from callbacks
The add_dev and remove_dev callbacks in struct class_interface currently pass in a pointer back to the class_interface structure that is calling them, but none of the callback implementations actually use this pointer as it is pointless (the structure is known, the driver passed it in in the first place if it is really needed again.) So clean this up and just remove the pointer from the callbacks and fix up all callback functions. Cc: Jean Delvare <jdelvare@suse.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com> Cc: Jon Mason <jdmason@kudzu.us> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Allen Hubbe <allenbh@gmail.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alex.bou9@gmail.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: John Stultz <jstultz@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Wang Weiyang <wangweiyang2@huawei.com> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: Jakob Koschel <jakobkoschel@gmail.com> Cc: Cai Xinchen <caixinchen1@huawei.com> Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Logan Gunthorpe <logang@deltatee.com> Link: https://lore.kernel.org/r/2023040250-pushover-platter-509c@gregkh Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Linus Torvalds
|
560b803067 |
Updates for timekeeping, timers and clockevent/source drivers:
Core:
- Yet another round of improvements to make the clocksource watchdog
more robust:
- Relax the clocksource-watchdog skew criteria to match the NTP
criteria.
- Temporarily skip the watchdog when high memory latencies are
detected which can lead to false-positives.
- Provide an option to enable TSC skew detection even on systems
where TSC is marked as reliable.
Sigh!
- Initialize the restart block in the nanosleep syscalls to be directed
to the no restart function instead of doing a partial setup on entry.
This prevents an erroneous restart_syscall() invocation from
corrupting user space data. While such a situation is clearly a user
space bug, preventing this is a correctness issue and caters to the
least suprise principle.
- Ignore the hrtimer slack for realtime tasks in schedule_hrtimeout()
to align it with the nanosleep semantics.
Drivers:
- The obligatory new driver bindings for Mediatek, Rockchip and RISC-V
variants.
- Add support for the C3STOP misfeature to the RISC-V timer to handle
the case where the timer stops in deeper idle state.
- Set up a static key in the RISC-V timer correctly before first use.
- The usual small improvements and fixes all over the place
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Merge tag 'timers-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"Updates for timekeeping, timers and clockevent/source drivers:
Core:
- Yet another round of improvements to make the clocksource watchdog
more robust:
- Relax the clocksource-watchdog skew criteria to match the NTP
criteria.
- Temporarily skip the watchdog when high memory latencies are
detected which can lead to false-positives.
- Provide an option to enable TSC skew detection even on systems
where TSC is marked as reliable.
Sigh!
- Initialize the restart block in the nanosleep syscalls to be
directed to the no restart function instead of doing a partial
setup on entry.
This prevents an erroneous restart_syscall() invocation from
corrupting user space data. While such a situation is clearly a
user space bug, preventing this is a correctness issue and caters
to the least suprise principle.
- Ignore the hrtimer slack for realtime tasks in schedule_hrtimeout()
to align it with the nanosleep semantics.
Drivers:
- The obligatory new driver bindings for Mediatek, Rockchip and
RISC-V variants.
- Add support for the C3STOP misfeature to the RISC-V timer to handle
the case where the timer stops in deeper idle state.
- Set up a static key in the RISC-V timer correctly before first use.
- The usual small improvements and fixes all over the place"
* tag 'timers-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
clocksource/drivers/timer-sun4i: Add CLOCK_EVT_FEAT_DYNIRQ
clocksource/drivers/em_sti: Mark driver as non-removable
clocksource/drivers/sh_tmu: Mark driver as non-removable
clocksource/drivers/riscv: Patch riscv_clock_next_event() jump before first use
clocksource/drivers/timer-microchip-pit64b: Add delay timer
clocksource/drivers/timer-microchip-pit64b: Select driver only on ARM
dt-bindings: timer: sifive,clint: add comaptibles for T-Head's C9xx
dt-bindings: timer: mediatek,mtk-timer: add MT8365
clocksource/drivers/riscv: Get rid of clocksource_arch_init() callback
clocksource/drivers/sh_cmt: Mark driver as non-removable
clocksource/drivers/timer-microchip-pit64b: Drop obsolete dependency on COMPILE_TEST
clocksource/drivers/riscv: Increase the clock source rating
clocksource/drivers/timer-riscv: Set CLOCK_EVT_FEAT_C3STOP based on DT
dt-bindings: timer: Add bindings for the RISC-V timer device
RISC-V: time: initialize hrtimer based broadcast clock event device
dt-bindings: timer: rk-timer: Add rktimer for rv1126
time/debug: Fix memory leak with using debugfs_lookup()
clocksource: Enable TSC watchdog checking of HPET and PMTMR only when requested
posix-timers: Use atomic64_try_cmpxchg() in __update_gt_cputime()
clocksource: Verify HPET and PMTMR when TSC unverified
...
|
||
|
Linus Torvalds
|
1f2d9ffc7a |
Scheduler updates in this cycle are:
- Improve the scalability of the CFS bandwidth unthrottling logic
with large number of CPUs.
- Fix & rework various cpuidle routines, simplify interaction with
the generic scheduler code. Add __cpuidle methods as noinstr to
objtool's noinstr detection and fix boatloads of cpuidle bugs & quirks.
- Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS,
to query previously issued registrations.
- Limit scheduler slice duration to the sysctl_sched_latency period,
to improve scheduling granularity with a large number of SCHED_IDLE
tasks.
- Debuggability enhancement on sys_exit(): warn about disabled IRQs,
but also enable them to prevent a cascade of followup problems and
repeat warnings.
- Fix the rescheduling logic in prio_changed_dl().
- Micro-optimize cpufreq and sched-util methods.
- Micro-optimize ttwu_runnable()
- Micro-optimize the idle-scanning in update_numa_stats(),
select_idle_capacity() and steal_cookie_task().
- Update the RSEQ code & self-tests
- Constify various scheduler methods
- Remove unused methods
- Refine __init tags
- Documentation updates
- ... Misc other cleanups, fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Improve the scalability of the CFS bandwidth unthrottling logic with
large number of CPUs.
- Fix & rework various cpuidle routines, simplify interaction with the
generic scheduler code. Add __cpuidle methods as noinstr to objtool's
noinstr detection and fix boatloads of cpuidle bugs & quirks.
- Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS, to query
previously issued registrations.
- Limit scheduler slice duration to the sysctl_sched_latency period, to
improve scheduling granularity with a large number of SCHED_IDLE
tasks.
- Debuggability enhancement on sys_exit(): warn about disabled IRQs,
but also enable them to prevent a cascade of followup problems and
repeat warnings.
- Fix the rescheduling logic in prio_changed_dl().
- Micro-optimize cpufreq and sched-util methods.
- Micro-optimize ttwu_runnable()
- Micro-optimize the idle-scanning in update_numa_stats(),
select_idle_capacity() and steal_cookie_task().
- Update the RSEQ code & self-tests
- Constify various scheduler methods
- Remove unused methods
- Refine __init tags
- Documentation updates
- Misc other cleanups, fixes
* tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits)
sched/rt: pick_next_rt_entity(): check list_entry
sched/deadline: Add more reschedule cases to prio_changed_dl()
sched/fair: sanitize vruntime of entity being placed
sched/fair: Remove capacity inversion detection
sched/fair: unlink misfit task from cpu overutilized
objtool: mem*() are not uaccess safe
cpuidle: Fix poll_idle() noinstr annotation
sched/clock: Make local_clock() noinstr
sched/clock/x86: Mark sched_clock() noinstr
x86/pvclock: Improve atomic update of last_value in pvclock_clocksource_read()
x86/atomics: Always inline arch_atomic64*()
cpuidle: tracing, preempt: Squash _rcuidle tracing
cpuidle: tracing: Warn about !rcu_is_watching()
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
cpuidle: drivers: firmware: psci: Dont instrument suspend code
KVM: selftests: Fix build of rseq test
exit: Detect and fix irq disabled state in oops
cpuidle, arm64: Fix the ARM64 cpuidle logic
cpuidle: mvebu: Fix duplicate flags assignment
sched/fair: Limit sched slice duration
...
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Thomas Gleixner
|
d125d1349a |
alarmtimer: Prevent starvation by small intervals and SIG_IGN
syzbot reported a RCU stall which is caused by setting up an alarmtimer with a very small interval and ignoring the signal. The reproducer arms the alarm timer with a relative expiry of 8ns and an interval of 9ns. Not a problem per se, but that's an issue when the signal is ignored because then the timer is immediately rearmed because there is no way to delay that rearming to the signal delivery path. See posix_timer_fn() and commit |
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Thomas Gleixner
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ab407a1919 |
Clocksource watchdog commits for v6.3
This pull request contains the following:
o Improvements to clocksource-watchdog console messages.
o Loosening of the clocksource-watchdog skew criteria to match
those of NTP (500 parts per million, relaxed from 400 parts
per million). If it is good enough for NTP, it is good enough
for the clocksource watchdog.
o Suspend clocksource-watchdog checking temporarily when high
memory latencies are detected. This avoids the false-positive
clock-skew events that have been seen on production systems
running memory-intensive workloads.
o On systems where the TSC is deemed trustworthy, use it as the
watchdog timesource, but only when specifically requested using
the tsc=watchdog kernel boot parameter. This permits clock-skew
events to be detected, but avoids forcing workloads to use the
slow HPET and ACPI PM timers. These last two timers are slow
enough to cause systems to be needlessly marked bad on the one
hand, and real skew does sometimes happen on production systems
running production workloads on the other. And sometimes it is
the fault of the TSC, or at least of the firmware that told the
kernel to program the TSC with the wrong frequency.
o Add a tsc=revalidate kernel boot parameter to allow the kernel
to diagnose cases where the TSC hardware works fine, but was told
by firmware to tick at the wrong frequency. Such cases are rare,
but they really have happened on production systems.
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Merge tag 'clocksource.2023.02.06b' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into timers/core
Pull clocksource watchdog changes from Paul McKenney:
o Improvements to clocksource-watchdog console messages.
o Loosening of the clocksource-watchdog skew criteria to match
those of NTP (500 parts per million, relaxed from 400 parts
per million). If it is good enough for NTP, it is good enough
for the clocksource watchdog.
o Suspend clocksource-watchdog checking temporarily when high
memory latencies are detected. This avoids the false-positive
clock-skew events that have been seen on production systems
running memory-intensive workloads.
o On systems where the TSC is deemed trustworthy, use it as the
watchdog timesource, but only when specifically requested using
the tsc=watchdog kernel boot parameter. This permits clock-skew
events to be detected, but avoids forcing workloads to use the
slow HPET and ACPI PM timers. These last two timers are slow
enough to cause systems to be needlessly marked bad on the one
hand, and real skew does sometimes happen on production systems
running production workloads on the other. And sometimes it is
the fault of the TSC, or at least of the firmware that told the
kernel to program the TSC with the wrong frequency.
o Add a tsc=revalidate kernel boot parameter to allow the kernel
to diagnose cases where the TSC hardware works fine, but was told
by firmware to tick at the wrong frequency. Such cases are rare,
but they really have happened on production systems.
Link: https://lore.kernel.org/r/20230210193640.GA3325193@paulmck-ThinkPad-P17-Gen-1
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Greg Kroah-Hartman
|
5b268d8aba |
time/debug: Fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230202151214.2306822-1-gregkh@linuxfoundation.org |
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Uros Bizjak
|
915d4ad383 |
posix-timers: Use atomic64_try_cmpxchg() in __update_gt_cputime()
Use atomic64_try_cmpxchg() instead of atomic64_cmpxchg() in __update_gt_cputime(). The x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg() (and related move instruction in front of cmpxchg()). Also, atomic64_try_cmpxchg() implicitly assigns old *ptr value to "old" when cmpxchg() fails. There is no need to re-read the value in the loop. No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230116165337.5810-1-ubizjak@gmail.com |
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Ingo Molnar
|
57a30218fa |
Linux 6.2-rc6
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Davidlohr Bueso
|
0c52310f26 |
hrtimer: Ignore slack time for RT tasks in schedule_hrtimeout_range()
While in theory the timer can be triggered before expires + delta, for the cases of RT tasks they really have no business giving any lenience for extra slack time, so override any passed value by the user and always use zero for schedule_hrtimeout_range() calls. Furthermore, this is similar to what the nanosleep(2) family already does with current->timer_slack_ns. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230123173206.6764-3-dave@stgolabs.net |
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Davidlohr Bueso
|
c14fd3dcac |
hrtimer: Rely on rt_task() for DL tasks too
Checking dl_task() is redundant as rt_task() returns true for deadline tasks too. Signed-off-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230123173206.6764-2-dave@stgolabs.net |
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Feng Tang
|
b7082cdfc4 |
clocksource: Suspend the watchdog temporarily when high read latency detected
Bugs have been reported on 8 sockets x86 machines in which the TSC was wrongly disabled when the system is under heavy workload. [ 818.380354] clocksource: timekeeping watchdog on CPU336: hpet wd-wd read-back delay of 1203520ns [ 818.436160] clocksource: wd-tsc-wd read-back delay of 181880ns, clock-skew test skipped! [ 819.402962] clocksource: timekeeping watchdog on CPU338: hpet wd-wd read-back delay of 324000ns [ 819.448036] clocksource: wd-tsc-wd read-back delay of 337240ns, clock-skew test skipped! [ 819.880863] clocksource: timekeeping watchdog on CPU339: hpet read-back delay of 150280ns, attempt 3, marking unstable [ 819.936243] tsc: Marking TSC unstable due to clocksource watchdog [ 820.068173] TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'. [ 820.092382] sched_clock: Marking unstable (818769414384, 1195404998) [ 820.643627] clocksource: Checking clocksource tsc synchronization from CPU 267 to CPUs 0,4,25,70,126,430,557,564. [ 821.067990] clocksource: Switched to clocksource hpet This can be reproduced by running memory intensive 'stream' tests, or some of the stress-ng subcases such as 'ioport'. The reason for these issues is the when system is under heavy load, the read latency of the clocksources can be very high. Even lightweight TSC reads can show high latencies, and latencies are much worse for external clocksources such as HPET or the APIC PM timer. These latencies can result in false-positive clocksource-unstable determinations. These issues were initially reported by a customer running on a production system, and this problem was reproduced on several generations of Xeon servers, especially when running the stress-ng test. These Xeon servers were not production systems, but they did have the latest steppings and firmware. Given that the clocksource watchdog is a continual diagnostic check with frequency of twice a second, there is no need to rush it when the system is under heavy load. Therefore, when high clocksource read latencies are detected, suspend the watchdog timer for 5 minutes. Signed-off-by: Feng Tang <feng.tang@intel.com> Acked-by: Waiman Long <longman@redhat.com> Cc: John Stultz <jstultz@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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Peter Zijlstra
|
e3ee5e66f7 |
time/tick-broadcast: Remove RCU_NONIDLE() usage
No callers left that have already disabled RCU. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.927904612@infradead.org |
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Peter Zijlstra
|
a01353cf18 |
cpuidle: Fix ct_idle_*() usage
The whole disable-RCU, enable-IRQS dance is very intricate since changing IRQ state is traced, which depends on RCU. Add two helpers for the cpuidle case that mirror the entry code: ct_cpuidle_enter() ct_cpuidle_exit() And fix all the cases where the enter/exit dance was buggy. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.130014793@infradead.org |
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Jann Horn
|
9f76d59173 |
timers: Prevent union confusion from unexpected restart_syscall()
The nanosleep syscalls use the restart_block mechanism, with a quirk: The `type` and `rmtp`/`compat_rmtp` fields are set up unconditionally on syscall entry, while the rest of the restart_block is only set up in the unlikely case that the syscall is actually interrupted by a signal (or pseudo-signal) that doesn't have a signal handler. If the restart_block was set up by a previous syscall (futex(..., FUTEX_WAIT, ...) or poll()) and hasn't been invalidated somehow since then, this will clobber some of the union fields used by futex_wait_restart() and do_restart_poll(). If userspace afterwards wrongly calls the restart_syscall syscall, futex_wait_restart()/do_restart_poll() will read struct fields that have been clobbered. This doesn't actually lead to anything particularly interesting because none of the union fields contain trusted kernel data, and futex(..., FUTEX_WAIT, ...) and poll() aren't syscalls where it makes much sense to apply seccomp filters to their arguments. So the current consequences are just of the "if userspace does bad stuff, it can damage itself, and that's not a problem" flavor. But still, it seems like a hazard for future developers, so invalidate the restart_block when partly setting it up in the nanosleep syscalls. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230105134403.754986-1-jannh@google.com |
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Paul E. McKenney
|
dd02926994 |
clocksource: Improve "skew is too large" messages
When clocksource_watchdog() detects excessive clocksource skew compared to the watchdog clocksource, it marks the clocksource under test as unstable and prints several lines worth of message. But that message is unclear to anyone unfamiliar with the code: clocksource: timekeeping watchdog on CPU2: Marking clocksource 'wdtest-ktime' as unstable because the skew is too large: clocksource: 'kvm-clock' wd_nsec: 400744390 wd_now: 612625c2c wd_last: 5fa7f7c66 mask: ffffffffffffffff clocksource: 'wdtest-ktime' cs_nsec: 600744034 cs_now: 173081397a292d4f cs_last: 17308139565a8ced mask: ffffffffffffffff clocksource: 'kvm-clock' (not 'wdtest-ktime') is current clocksource. Therefore, add the following line near the end of that message: Clocksource 'wdtest-ktime' skewed 199999644 ns (199 ms) over watchdog 'kvm-clock' interval of 400744390 ns (400 ms) This new line clearly indicates the amount of skew between the two clocksources, along with the duration of the time interval over which the skew occurred, both in nanoseconds and milliseconds. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: John Stultz <jstultz@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Feng Tang <feng.tang@intel.com> |
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Paul E. McKenney
|
f092eb34b3 |
clocksource: Improve read-back-delay message
When cs_watchdog_read() is unable to get a qualifying clocksource read within the limit set by max_cswd_read_retries, it prints a message and marks the clocksource under test as unstable. But that message is unclear to anyone unfamiliar with the code: clocksource: timekeeping watchdog on CPU13: wd-tsc-wd read-back delay 1000614ns, attempt 3, marking unstable Therefore, add some context so that the message appears as follows: clocksource: timekeeping watchdog on CPU13: wd-tsc-wd excessive read-back delay of 1000614ns vs. limit of 125000ns, wd-wd read-back delay only 27ns, attempt 3, marking tsc unstable Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: John Stultz <jstultz@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Feng Tang <feng.tang@intel.com> |
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Paul E. McKenney
|
c37e85c135 |
clocksource: Loosen clocksource watchdog constraints
Currently, MAX_SKEW_USEC is set to 100 microseconds, which has worked reasonably well. However, NTP is willing to tolerate 500 microseconds of skew per second, and a clocksource that is good enough for NTP should be good enough for the clocksource watchdog. The watchdog's skew is controlled by MAX_SKEW_USEC and the CLOCKSOURCE_WATCHDOG_MAX_SKEW_US Kconfig option. However, these values are doubled before being associated with a clocksource's ->uncertainty_margin, and the ->uncertainty_margin values of the pair of clocksource's being compared are summed before checking against the skew. Therefore, set both MAX_SKEW_USEC and the default for the CLOCKSOURCE_WATCHDOG_MAX_SKEW_US Kconfig option to 125 microseconds of skew per second, resulting in 500 microseconds of skew per second in the clocksource watchdog's skew comparison. Suggested-by Rik van Riel <riel@surriel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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Yunying Sun
|
beaa1ffe55 |
clocksource: Print clocksource name when clocksource is tested unstable
Some "TSC fall back to HPET" messages appear on systems having more than 2 NUMA nodes: clocksource: timekeeping watchdog on CPU168: hpet read-back delay of 4296200ns, attempt 4, marking unstable The "hpet" here is misleading the clocksource watchdog is really doing repeated reads of "hpet" in order to check for unrelated delays. Therefore, print the name of the clocksource under test, prefixed by "wd-" and suffixed by "-wd", for example, "wd-tsc-wd". Signed-off-by: Yunying Sun <yunying.sun@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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Randy Dunlap
|
f3cb80804b |
time: Fix various kernel-doc problems
Clean up kernel-doc complaints about function names and non-kernel-doc comments in kernel/time/. Fixes these warnings: kernel/time/time.c:479: warning: expecting prototype for set_normalized_timespec(). Prototype was for set_normalized_timespec64() instead kernel/time/time.c:553: warning: expecting prototype for msecs_to_jiffies(). Prototype was for __msecs_to_jiffies() instead kernel/time/timekeeping.c:1595: warning: contents before sections kernel/time/timekeeping.c:1705: warning: This comment starts with '/**', but isn't a kernel-doc comment. * We have three kinds of time sources to use for sleep time kernel/time/timekeeping.c:1726: warning: This comment starts with '/**', but isn't a kernel-doc comment. * 1) can be determined whether to use or not only when doing kernel/time/tick-oneshot.c:21: warning: missing initial short description on line: * tick_program_event kernel/time/tick-oneshot.c:107: warning: expecting prototype for tick_check_oneshot_mode(). Prototype was for tick_oneshot_mode_active() instead Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230103032849.12723-1-rdunlap@infradead.org |
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|
Linus Torvalds
|
268325bda5 |
Random number generator updates for Linux 6.2-rc1.
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Merge tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
- Replace prandom_u32_max() and various open-coded variants of it,
there is now a new family of functions that uses fast rejection
sampling to choose properly uniformly random numbers within an
interval:
get_random_u32_below(ceil) - [0, ceil)
get_random_u32_above(floor) - (floor, U32_MAX]
get_random_u32_inclusive(floor, ceil) - [floor, ceil]
Coccinelle was used to convert all current users of
prandom_u32_max(), as well as many open-coded patterns, resulting in
improvements throughout the tree.
I'll have a "late" 6.1-rc1 pull for you that removes the now unused
prandom_u32_max() function, just in case any other trees add a new
use case of it that needs to converted. According to linux-next,
there may be two trivial cases of prandom_u32_max() reintroductions
that are fixable with a 's/.../.../'. So I'll have for you a final
conversion patch doing that alongside the removal patch during the
second week.
This is a treewide change that touches many files throughout.
- More consistent use of get_random_canary().
- Updates to comments, documentation, tests, headers, and
simplification in configuration.
- The arch_get_random*_early() abstraction was only used by arm64 and
wasn't entirely useful, so this has been replaced by code that works
in all relevant contexts.
- The kernel will use and manage random seeds in non-volatile EFI
variables, refreshing a variable with a fresh seed when the RNG is
initialized. The RNG GUID namespace is then hidden from efivarfs to
prevent accidental leakage.
These changes are split into random.c infrastructure code used in the
EFI subsystem, in this pull request, and related support inside of
EFISTUB, in Ard's EFI tree. These are co-dependent for full
functionality, but the order of merging doesn't matter.
- Part of the infrastructure added for the EFI support is also used for
an improvement to the way vsprintf initializes its siphash key,
replacing an sleep loop wart.
- The hardware RNG framework now always calls its correct random.c
input function, add_hwgenerator_randomness(), rather than sometimes
going through helpers better suited for other cases.
- The add_latent_entropy() function has long been called from the fork
handler, but is a no-op when the latent entropy gcc plugin isn't
used, which is fine for the purposes of latent entropy.
But it was missing out on the cycle counter that was also being mixed
in beside the latent entropy variable. So now, if the latent entropy
gcc plugin isn't enabled, add_latent_entropy() will expand to a call
to add_device_randomness(NULL, 0), which adds a cycle counter,
without the absent latent entropy variable.
- The RNG is now reseeded from a delayed worker, rather than on demand
when used. Always running from a worker allows it to make use of the
CPU RNG on platforms like S390x, whose instructions are too slow to
do so from interrupts. It also has the effect of adding in new inputs
more frequently with more regularity, amounting to a long term
transcript of random values. Plus, it helps a bit with the upcoming
vDSO implementation (which isn't yet ready for 6.2).
- The jitter entropy algorithm now tries to execute on many different
CPUs, round-robining, in hopes of hitting even more memory latencies
and other unpredictable effects. It also will mix in a cycle counter
when the entropy timer fires, in addition to being mixed in from the
main loop, to account more explicitly for fluctuations in that timer
firing. And the state it touches is now kept within the same cache
line, so that it's assured that the different execution contexts will
cause latencies.
* tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits)
random: include <linux/once.h> in the right header
random: align entropy_timer_state to cache line
random: mix in cycle counter when jitter timer fires
random: spread out jitter callback to different CPUs
random: remove extraneous period and add a missing one in comments
efi: random: refresh non-volatile random seed when RNG is initialized
vsprintf: initialize siphash key using notifier
random: add back async readiness notifier
random: reseed in delayed work rather than on-demand
random: always mix cycle counter in add_latent_entropy()
hw_random: use add_hwgenerator_randomness() for early entropy
random: modernize documentation comment on get_random_bytes()
random: adjust comment to account for removed function
random: remove early archrandom abstraction
random: use random.trust_{bootloader,cpu} command line option only
stackprotector: actually use get_random_canary()
stackprotector: move get_random_canary() into stackprotector.h
treewide: use get_random_u32_inclusive() when possible
treewide: use get_random_u32_{above,below}() instead of manual loop
treewide: use get_random_u32_below() instead of deprecated function
...
|
||
|
Lukas Bulwahn
|
ebe1173283 |
clockevents: Repair kernel-doc for clockevent_delta2ns()
Since the introduction of clockevents, i.e., commit
|
||
|
Jann Horn
|
d6c494e8ee |
vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy
find_timens_vvar_page() is not architecture-specific, as can be seen from how all five per-architecture versions of it are the same. (arm64, powerpc and riscv are exactly the same; x86 and s390 have two characters difference inside a comment, less blank lines, and mark the !CONFIG_TIME_NS version as inline.) Refactor the five copies into a central copy in kernel/time/namespace.c. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20221130115320.2918447-1-jannh@google.com |
||
|
Thomas Gleixner
|
f571faf6e4 |
timers: Provide timer_shutdown[_sync]()
Tearing down timers which have circular dependencies to other functionality, e.g. workqueues, where the timer can schedule work and work can arm timers, is not trivial. In those cases it is desired to shutdown the timer in a way which prevents rearming of the timer. The mechanism to do so is to set timer->function to NULL and use this as an indicator for the timer arming functions to ignore the (re)arm request. Expose new interfaces for this: timer_shutdown_sync() and timer_shutdown(). timer_shutdown_sync() has the same functionality as timer_delete_sync() plus the NULL-ification of the timer function. timer_shutdown() has the same functionality as timer_delete() plus the NULL-ification of the timer function. In both cases the rearming of the timer is prevented by silently discarding rearm attempts due to timer->function being NULL. Co-developed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/20221123201625.314230270@linutronix.de |
||
|
Thomas Gleixner
|
0cc04e8045 |
timers: Add shutdown mechanism to the internal functions
Tearing down timers which have circular dependencies to other functionality, e.g. workqueues, where the timer can schedule work and work can arm timers, is not trivial. In those cases it is desired to shutdown the timer in a way which prevents rearming of the timer. The mechanism to do so is to set timer->function to NULL and use this as an indicator for the timer arming functions to ignore the (re)arm request. Add a shutdown argument to the relevant internal functions which makes the actual deactivation code set timer->function to NULL which in turn prevents rearming of the timer. Co-developed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/20221123201625.253883224@linutronix.de |
||
|
Thomas Gleixner
|
8553b5f277 |
timers: Split [try_to_]del_timer[_sync]() to prepare for shutdown mode
Tearing down timers which have circular dependencies to other functionality, e.g. workqueues, where the timer can schedule work and work can arm timers, is not trivial. In those cases it is desired to shutdown the timer in a way which prevents rearming of the timer. The mechanism to do so is to set timer->function to NULL and use this as an indicator for the timer arming functions to ignore the (re)arm request. Split the inner workings of try_do_del_timer_sync(), del_timer_sync() and del_timer() into helper functions to prepare for implementing the shutdown functionality. No functional change. Co-developed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/20221123201625.195147423@linutronix.de |
||
|
Thomas Gleixner
|
d02e382cef |
timers: Silently ignore timers with a NULL function
Tearing down timers which have circular dependencies to other functionality, e.g. workqueues, where the timer can schedule work and work can arm timers, is not trivial. In those cases it is desired to shutdown the timer in a way which prevents rearming of the timer. The mechanism to do so is to set timer->function to NULL and use this as an indicator for the timer arming functions to ignore the (re)arm request. In preparation for that replace the warnings in the relevant code paths with checks for timer->function == NULL. If the pointer is NULL, then discard the rearm request silently. Add debug_assert_init() instead of the WARN_ON_ONCE(!timer->function) checks so that debug objects can warn about non-initialized timers. The warning of debug objects does not warn if timer->function == NULL. It warns when timer was not initialized using timer_setup[_on_stack]() or via DEFINE_TIMER(). If developers fail to enable debug objects and then waste lots of time to figure out why their non-initialized timer is not firing, they deserve it. Same for initializing a timer with a NULL function. Co-developed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/87wn7kdann.ffs@tglx |
||
|
Thomas Gleixner
|
bb663f0f3c |
timers: Rename del_timer() to timer_delete()
The timer related functions do not have a strict timer_ prefixed namespace which is really annoying. Rename del_timer() to timer_delete() and provide del_timer() as a wrapper. Document that del_timer() is not for new code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201625.015535022@linutronix.de |
||
|
Thomas Gleixner
|
9b13df3fb6 |
timers: Rename del_timer_sync() to timer_delete_sync()
The timer related functions do not have a strict timer_ prefixed namespace which is really annoying. Rename del_timer_sync() to timer_delete_sync() and provide del_timer_sync() as a wrapper. Document that del_timer_sync() is not for new code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201624.954785441@linutronix.de |
||
|
Thomas Gleixner
|
168f6b6ffb |
timers: Use del_timer_sync() even on UP
del_timer_sync() is assumed to be pointless on uniprocessor systems and can be mapped to del_timer() because in theory del_timer() can never be invoked while the timer callback function is executed. This is not entirely true because del_timer() can be invoked from interrupt context and therefore hit in the middle of a running timer callback. Contrary to that del_timer_sync() is not allowed to be invoked from interrupt context unless the affected timer is marked with TIMER_IRQSAFE. del_timer_sync() has proper checks in place to detect such a situation. Give up on the UP optimization and make del_timer_sync() unconditionally available. Co-developed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/20221123201624.888306160@linutronix.de |
||
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Thomas Gleixner
|
14f043f134 |
timers: Update kernel-doc for various functions
The kernel-doc of timer related functions is partially uncomprehensible word salad. Rewrite it to make it useful. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201624.828703870@linutronix.de |
||
|
Thomas Gleixner
|
82ed6f7ef5 |
timers: Replace BUG_ON()s
The timer code still has a few BUG_ON()s left which are crashing the kernel in situations where it still can recover or simply refuse to take an action. Remove the one in the hotplug callback which checks for the CPU being offline. If that happens then the whole hotplug machinery will explode in colourful ways. Replace the rest with WARN_ON_ONCE() and conditional returns where appropriate. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201624.769128888@linutronix.de |
||
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Thomas Gleixner
|
9a5a305686 |
timers: Get rid of del_singleshot_timer_sync()
del_singleshot_timer_sync() used to be an optimization for deleting timers which are not rearmed from the timer callback function. This optimization turned out to be broken and got mapped to del_timer_sync() about 17 years ago. Get rid of the undocumented indirection and use del_timer_sync() directly. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201624.706987932@linutronix.de |
||
|
Jason A. Donenfeld
|
8032bf1233 |
treewide: use get_random_u32_below() instead of deprecated function
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
||
|
ye xingchen
|
8be3f96ced |
timers: Replace in_irq() with in_hardirq()
Replace the obsolete and ambiguous macro in_irq() with new macro in_hardirq(). Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/r/20221012012629.334966-1-ye.xingchen@zte.com.cn |
||
|
Jason A. Donenfeld
|
81895a65ec |
treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
||
|
Linus Torvalds
|
30c999937f |
Scheduler changes for v6.1:
- Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
- Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
- Freezer:
- Rewrite the core freezer to behave better wrt thawing and be simpler
in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
all the fallout.
- Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
- Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Debuggability:
- Change most occurances of BUG_ON() to WARN_ON_ONCE()
- Reorganize & fix TASK_ state comparisons, turn it into a bitmap
- Update/fix misc scheduler debugging facilities
Load-balancing & regular scheduling:
- Improve the behavior of the scheduler in presence of lot of
SCHED_IDLE tasks - in particular they should not impact other
scheduling classes.
- Optimize task load tracking, cleanups & fixes
- Clean up & simplify misc load-balancing code
Freezer:
- Rewrite the core freezer to behave better wrt thawing and be
simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
fixing/adjusting all the fallout.
Deadline scheduler:
- Fix the DL capacity-aware code
- Factor out dl_task_is_earliest_deadline() &
replenish_dl_new_period()
- Relax/optimize locking in task_non_contending()
Cleanups:
- Factor out the update_current_exec_runtime() helper
- Various cleanups, simplifications"
* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
sched: Fix more TASK_state comparisons
sched: Fix TASK_state comparisons
sched/fair: Move call to list_last_entry() in detach_tasks
sched/fair: Cleanup loop_max and loop_break
sched/fair: Make sure to try to detach at least one movable task
sched: Show PF_flag holes
freezer,sched: Rewrite core freezer logic
sched: Widen TAKS_state literals
sched/wait: Add wait_event_state()
sched/completion: Add wait_for_completion_state()
sched: Add TASK_ANY for wait_task_inactive()
sched: Change wait_task_inactive()s match_state
freezer,umh: Clean up freezer/initrd interaction
freezer: Have {,un}lock_system_sleep() save/restore flags
sched: Rename task_running() to task_on_cpu()
sched/fair: Cleanup for SIS_PROP
sched/fair: Default to false in test_idle_cores()
sched/fair: Remove useless check in select_idle_core()
sched/fair: Avoid double search on same cpu
sched/fair: Remove redundant check in select_idle_smt()
...
|
||
|
Peter Zijlstra
|
f5d39b0208 |
freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.
By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.
As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).
Specifically; the current scheme works a little like:
freezer_do_not_count();
schedule();
freezer_count();
And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.
However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.
That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.
This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.
As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:
TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN
The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).
The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.
With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
|
||
|
Youngmin Nam
|
46dae32fe6 |
time: Correct the prototype of ns_to_kernel_old_timeval and ns_to_timespec64
In ns_to_kernel_old_timeval() definition, the function argument is defined
with const identifier in kernel/time/time.c, but the prototype in
include/linux/time32.h looks different.
- The function is defined in kernel/time/time.c as below:
struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec)
- The function is decalared in include/linux/time32.h as below:
extern struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec);
Because the variable of arithmethic types isn't modified in the calling scope,
there's no need to mark arguments as const, which was already mentioned during
review (Link[1) of the original patch.
Likewise remove the "const" keyword in both definition and declaration of
ns_to_timespec64() as requested by Arnd (Link[2]).
Fixes:
|
||
|
Jiri Slaby
|
221f9d9cdf |
posix-timers: Make do_clock_gettime() static
do_clock_gettime() is used only in posix-stubs.c, so make it static. It avoids a compiler warning too: time/posix-stubs.c:73:5: warning: no previous prototype for ‘do_clock_gettime’ [-Wmissing-prototypes] Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220719085620.30567-1-jslaby@suse.cz |
||
|
Linus Torvalds
|
f86d1fbbe7 |
Networking changes for 6.0.
Core
----
- Refactor the forward memory allocation to better cope with memory
pressure with many open sockets, moving from a per socket cache to
a per-CPU one
- Replace rwlocks with RCU for better fairness in ping, raw sockets
and IP multicast router.
- Network-side support for IO uring zero-copy send.
- A few skb drop reason improvements, including codegen the source file
with string mapping instead of using macro magic.
- Rename reference tracking helpers to a more consistent
netdev_* schema.
- Adapt u64_stats_t type to address load/store tearing issues.
- Refine debug helper usage to reduce the log noise caused by bots.
BPF
---
- Improve socket map performance, avoiding skb cloning on read
operation.
- Add support for 64 bits enum, to match types exposed by kernel.
- Introduce support for sleepable uprobes program.
- Introduce support for enum textual representation in libbpf.
- New helpers to implement synproxy with eBPF/XDP.
- Improve loop performances, inlining indirect calls when
possible.
- Removed all the deprecated libbpf APIs.
- Implement new eBPF-based LSM flavor.
- Add type match support, which allow accurate queries to the
eBPF used types.
- A few TCP congetsion control framework usability improvements.
- Add new infrastructure to manipulate CT entries via eBPF programs.
- Allow for livepatch (KLP) and BPF trampolines to attach to the same
kernel function.
Protocols
---------
- Introduce per network namespace lookup tables for unix sockets,
increasing scalability and reducing contention.
- Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support.
- Add support to forciby close TIME_WAIT TCP sockets via user-space
tools.
- Significant performance improvement for the TLS 1.3 receive path,
both for zero-copy and not-zero-copy.
- Support for changing the initial MTPCP subflow priority/backup
status
- Introduce virtually contingus buffers for sockets over RDMA,
to cope better with memory pressure.
- Extend CAN ethtool support with timestamping capabilities
- Refactor CAN build infrastructure to allow building only the needed
features.
Driver API
----------
- Remove devlink mutex to allow parallel commands on multiple links.
- Add support for pause stats in distributed switch.
- Implement devlink helpers to query and flash line cards.
- New helper for phy mode to register conversion.
New hardware / drivers
----------------------
- Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro.
- Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch.
- Ethernet DSA driver for the Microchip LAN937x switch.
- Ethernet PHY driver for the Aquantia AQR113C EPHY.
- CAN driver for the OBD-II ELM327 interface.
- CAN driver for RZ/N1 SJA1000 CAN controller.
- Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device.
Drivers
-------
- Intel Ethernet NICs:
- i40e: add support for vlan pruning
- i40e: add support for XDP framented packets
- ice: improved vlan offload support
- ice: add support for PPPoE offload
- Mellanox Ethernet (mlx5)
- refactor packet steering offload for performance and scalability
- extend support for TC offload
- refactor devlink code to clean-up the locking schema
- support stacked vlans for bridge offloads
- use TLS objects pool to improve connection rate
- Netronome Ethernet NICs (nfp):
- extend support for IPv6 fields mangling offload
- add support for vepa mode in HW bridge
- better support for virtio data path acceleration (VDPA)
- enable TSO by default
- Microsoft vNIC driver (mana)
- add support for XDP redirect
- Others Ethernet drivers:
- bonding: add per-port priority support
- microchip lan743x: extend phy support
- Fungible funeth: support UDP segmentation offload and XDP xmit
- Solarflare EF100: add support for virtual function representors
- MediaTek SoC: add XDP support
- Mellanox Ethernet/IB switch (mlxsw):
- dropped support for unreleased H/W (XM router).
- improved stats accuracy
- unified bridge model coversion improving scalability
(parts 1-6)
- support for PTP in Spectrum-2 asics
- Broadcom PHYs
- add PTP support for BCM54210E
- add support for the BCM53128 internal PHY
- Marvell Ethernet switches (prestera):
- implement support for multicast forwarding offload
- Embedded Ethernet switches:
- refactor OcteonTx MAC filter for better scalability
- improve TC H/W offload for the Felix driver
- refactor the Microchip ksz8 and ksz9477 drivers to share
the probe code (parts 1, 2), add support for phylink
mac configuration
- Other WiFi:
- Microchip wilc1000: diable WEP support and enable WPA3
- Atheros ath10k: encapsulation offload support
Old code removal:
- Neterion vxge ethernet driver: this is untouched since more than
10 years.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking changes from Paolo Abeni:
"Core:
- Refactor the forward memory allocation to better cope with memory
pressure with many open sockets, moving from a per socket cache to
a per-CPU one
- Replace rwlocks with RCU for better fairness in ping, raw sockets
and IP multicast router.
- Network-side support for IO uring zero-copy send.
- A few skb drop reason improvements, including codegen the source
file with string mapping instead of using macro magic.
- Rename reference tracking helpers to a more consistent netdev_*
schema.
- Adapt u64_stats_t type to address load/store tearing issues.
- Refine debug helper usage to reduce the log noise caused by bots.
BPF:
- Improve socket map performance, avoiding skb cloning on read
operation.
- Add support for 64 bits enum, to match types exposed by kernel.
- Introduce support for sleepable uprobes program.
- Introduce support for enum textual representation in libbpf.
- New helpers to implement synproxy with eBPF/XDP.
- Improve loop performances, inlining indirect calls when possible.
- Removed all the deprecated libbpf APIs.
- Implement new eBPF-based LSM flavor.
- Add type match support, which allow accurate queries to the eBPF
used types.
- A few TCP congetsion control framework usability improvements.
- Add new infrastructure to manipulate CT entries via eBPF programs.
- Allow for livepatch (KLP) and BPF trampolines to attach to the same
kernel function.
Protocols:
- Introduce per network namespace lookup tables for unix sockets,
increasing scalability and reducing contention.
- Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support.
- Add support to forciby close TIME_WAIT TCP sockets via user-space
tools.
- Significant performance improvement for the TLS 1.3 receive path,
both for zero-copy and not-zero-copy.
- Support for changing the initial MTPCP subflow priority/backup
status
- Introduce virtually contingus buffers for sockets over RDMA, to
cope better with memory pressure.
- Extend CAN ethtool support with timestamping capabilities
- Refactor CAN build infrastructure to allow building only the needed
features.
Driver API:
- Remove devlink mutex to allow parallel commands on multiple links.
- Add support for pause stats in distributed switch.
- Implement devlink helpers to query and flash line cards.
- New helper for phy mode to register conversion.
New hardware / drivers:
- Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro.
- Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch.
- Ethernet DSA driver for the Microchip LAN937x switch.
- Ethernet PHY driver for the Aquantia AQR113C EPHY.
- CAN driver for the OBD-II ELM327 interface.
- CAN driver for RZ/N1 SJA1000 CAN controller.
- Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device.
Drivers:
- Intel Ethernet NICs:
- i40e: add support for vlan pruning
- i40e: add support for XDP framented packets
- ice: improved vlan offload support
- ice: add support for PPPoE offload
- Mellanox Ethernet (mlx5)
- refactor packet steering offload for performance and scalability
- extend support for TC offload
- refactor devlink code to clean-up the locking schema
- support stacked vlans for bridge offloads
- use TLS objects pool to improve connection rate
- Netronome Ethernet NICs (nfp):
- extend support for IPv6 fields mangling offload
- add support for vepa mode in HW bridge
- better support for virtio data path acceleration (VDPA)
- enable TSO by default
- Microsoft vNIC driver (mana)
- add support for XDP redirect
- Others Ethernet drivers:
- bonding: add per-port priority support
- microchip lan743x: extend phy support
- Fungible funeth: support UDP segmentation offload and XDP xmit
- Solarflare EF100: add support for virtual function representors
- MediaTek SoC: add XDP support
- Mellanox Ethernet/IB switch (mlxsw):
- dropped support for unreleased H/W (XM router).
- improved stats accuracy
- unified bridge model coversion improving scalability (parts 1-6)
- support for PTP in Spectrum-2 asics
- Broadcom PHYs
- add PTP support for BCM54210E
- add support for the BCM53128 internal PHY
- Marvell Ethernet switches (prestera):
- implement support for multicast forwarding offload
- Embedded Ethernet switches:
- refactor OcteonTx MAC filter for better scalability
- improve TC H/W offload for the Felix driver
- refactor the Microchip ksz8 and ksz9477 drivers to share the
probe code (parts 1, 2), add support for phylink mac
configuration
- Other WiFi:
- Microchip wilc1000: diable WEP support and enable WPA3
- Atheros ath10k: encapsulation offload support
Old code removal:
- Neterion vxge ethernet driver: this is untouched since more than 10 years"
* tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1890 commits)
doc: sfp-phylink: Fix a broken reference
wireguard: selftests: support UML
wireguard: allowedips: don't corrupt stack when detecting overflow
wireguard: selftests: update config fragments
wireguard: ratelimiter: use hrtimer in selftest
net/mlx5e: xsk: Discard unaligned XSK frames on striding RQ
net: usb: ax88179_178a: Bind only to vendor-specific interface
selftests: net: fix IOAM test skip return code
net: usb: make USB_RTL8153_ECM non user configurable
net: marvell: prestera: remove reduntant code
octeontx2-pf: Reduce minimum mtu size to 60
net: devlink: Fix missing mutex_unlock() call
net/tls: Remove redundant workqueue flush before destroy
net: txgbe: Fix an error handling path in txgbe_probe()
net: dsa: Fix spelling mistakes and cleanup code
Documentation: devlink: add add devlink-selftests to the table of contents
dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock
net: ionic: fix error check for vlan flags in ionic_set_nic_features()
net: ice: fix error NETIF_F_HW_VLAN_CTAG_FILTER check in ice_vsi_sync_fltr()
nfp: flower: add support for tunnel offload without key ID
...
|
||
|
Linus Torvalds
|
7d9d077c78 |
RCU pull request for v5.20 (or whatever)
This pull request contains the following branches: doc.2022.06.21a: Documentation updates. fixes.2022.07.19a: Miscellaneous fixes. nocb.2022.07.19a: Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms. poll.2022.07.21a: Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods. rcu-tasks.2022.06.21a: Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead. torture.2022.06.21a: Torture-test updates. ctxt.2022.07.05a: Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmLgMcgTHHBhdWxtY2tA a2VybmVsLm9yZwAKCRCevxLzctn7jArXD/0fjbCwqpRjHVTzjMY8jN4zDkqZZD6m g8Fx27hZ4ToNFwRptyHwNezrNj14skjAJEXfdjaVw32W62ivXvf0HINvSzsTLCSq k2kWyBdXLc9CwY5p5W4smnpn5VoAScjg5PoPL59INoZ/Zziji323C7Zepl/1DYJt 0T6bPCQjo1ZQoDUCyVpSjDmAqxnderWG0MeJVt74GkLqmnYLANg0GH8c7mH4+9LL kVGlLp5nlPgNJ4FEoFdMwNU8T/ETmaVld/m2dkiawjkXjJzB2XKtBigU91DDmXz5 7DIdV4ABrxiy4kGNqtIe/jFgnKyVD7xiDpyfjd6KTeDr/rDS8u2ZH7+1iHsyz3g0 Np/tS3vcd0KR+gI/d0eXxPbgm5sKlCmKw/nU2eArpW/+4LmVXBUfHTG9Jg+LJmBc JrUh6aEdIZJZHgv/nOQBNig7GJW43IG50rjuJxAuzcxiZNEG5lUSS23ysaA9CPCL PxRWKSxIEfK3kdmvVO5IIbKTQmIBGWlcWMTcYictFSVfBgcCXpPAksGvqA5JiUkc egW+xLFo/7K+E158vSKsVqlWZcEeUbsNJ88QOlpqnRgH++I2Yv/LhK41XfJfpH+Y ALxVaDd+mAq6v+qSHNVq9wT3ozXIPy/zK1hDlMIqx40h2YvaEsH4je+521oSoN9r vX60+QNxvUBLwA== =vUNm -----END PGP SIGNATURE----- Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms - Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods - Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead - Torture-test updates - Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y * tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits) rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings rcu: Diagnose extended sync_rcu_do_polled_gp() loops rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings rcutorture: Test polled expedited grace-period primitives rcu: Add polled expedited grace-period primitives rcutorture: Verify that polled GP API sees synchronous grace periods rcu: Make Tiny RCU grace periods visible to polled APIs rcu: Make polled grace-period API account for expedited grace periods rcu: Switch polled grace-period APIs to ->gp_seq_polled rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty rcu/nocb: Add option to opt rcuo kthreads out of RT priority rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread() rcu/nocb: Add an option to offload all CPUs on boot rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order rcu/nocb: Add/del rdp to iterate from rcuog itself rcu/tree: Add comment to describe GP-done condition in fqs loop rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs() rcu/kvfree: Remove useless monitor_todo flag rcu: Cleanup RCU urgency state for offline CPU ... |
||
|
Jason A. Donenfeld
|
151c8e499f |
wireguard: ratelimiter: use hrtimer in selftest
Using msleep() is problematic because it's compared against
ratelimiter.c's ktime_get_coarse_boottime_ns(), which means on systems
with slow jiffies (such as UML's forced HZ=100), the result is
inaccurate. So switch to using schedule_hrtimeout().
However, hrtimer gives us access only to the traditional posix timers,
and none of the _COARSE variants. So now, rather than being too
imprecise like jiffies, it's too precise.
One solution would be to give it a large "range" value, but this will
still fire early on a loaded system. A better solution is to align the
timeout to the actual coarse timer, and then round up to the nearest
tick, plus change.
So add the timeout to the current coarse time, and then
schedule_hrtimer() until the absolute computed time.
This should hopefully reduce flakes in CI as well. Note that we keep the
retry loop in case the entire function is running behind, because the
test could still be scheduled out, by either the kernel or by the
hypervisor's kernel, in which case restarting the test and hoping to not
be scheduled out still helps.
Fixes:
|
||
|
Jason A. Donenfeld
|
b8ac29b401 |
timekeeping: contribute wall clock to rng on time change
The rng's random_init() function contributes the real time to the rng at
boot time, so that events can at least start in relation to something
particular in the real world. But this clock might not yet be set that
point in boot, so nothing is contributed. In addition, the relation
between minor clock changes from, say, NTP, and the cycle counter is
potentially useful entropic data.
This commit addresses this by mixing in a time stamp on calls to
settimeofday and adjtimex. No entropy is credited in doing so, so it
doesn't make initialization faster, but it is still useful input to
have.
Fixes:
|
||
|
Oleg Nesterov
|
d5b36a4dbd |
fix race between exit_itimers() and /proc/pid/timers
As Chris explains, the comment above exit_itimers() is not correct, we can race with proc_timers_seq_ops. Change exit_itimers() to clear signal->posix_timers with ->siglock held. Cc: <stable@vger.kernel.org> Reported-by: chris@accessvector.net Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Frederic Weisbecker
|
e67198cc05 |
context_tracking: Take idle eqs entrypoints over RCU
The RCU dynticks counter is going to be merged into the context tracking subsystem. Start with moving the idle extended quiescent states entrypoints to context tracking. For now those are dumb redirections to existing RCU calls. [ paulmck: Apply kernel test robot feedback. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> |
||
|
Frederic Weisbecker
|
24a9c54182 |
context_tracking: Split user tracking Kconfig
Context tracking is going to be used not only to track user transitions but also idle/IRQs/NMIs. The user tracking part will then become a separate feature. Prepare Kconfig for that. [ frederic: Apply Max Filippov feedback. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> |
||
|
Frederic Weisbecker
|
2a0aafce96 |
context_tracking: Rename context_tracking_cpu_set() to ct_cpu_track_user()
context_tracking_cpu_set() is called in order to tell a CPU to track user/kernel transitions. Since context tracking is going to expand in to also track transitions from/to idle/IRQ/NMIs, the scope of this function name becomes too broad and needs to be made more specific. Also shorten the prefix to align with the new namespace. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> |
||
|
Masahiro Yamada
|
2390095113 |
tick/nohz: unexport __init-annotated tick_nohz_full_setup()
EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it had been broken for a decade. Commit |
||
|
Linus Torvalds
|
67850b7bdc |
While looking at the ptrace problems with PREEMPT_RT and the problems
of Peter Zijlstra was encountering with ptrace in his freezer rewrite I identified some cleanups to ptrace_stop that make sense on their own and move make resolving the other problems much simpler. The biggest issue is the habbit of the ptrace code to change task->__state from the tracer to suppress TASK_WAKEKILL from waking up the tracee. No other code in the kernel does that and it is straight forward to update signal_wake_up and friends to make that unnecessary. Peter's task freezer sets frozen tasks to a new state TASK_FROZEN and then it stores them by calling "wake_up_state(t, TASK_FROZEN)" relying on the fact that all stopped states except the special stop states can tolerate spurious wake up and recover their state. The state of stopped and traced tasked is changed to be stored in task->jobctl as well as in task->__state. This makes it possible for the freezer to recover tasks in these special states, as well as serving as a general cleanup. With a little more work in that direction I believe TASK_STOPPED can learn to tolerate spurious wake ups and become an ordinary stop state. The TASK_TRACED state has to remain a special state as the registers for a process are only reliably available when the process is stopped in the scheduler. Fundamentally ptrace needs acess to the saved register values of a task. There are bunch of semi-random ptrace related cleanups that were found while looking at these issues. One cleanup that deserves to be called out is from commit |
||
|
Linus Torvalds
|
ac2ab99072 |
Random number generator updates for Linux 5.19-rc1.
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Merge tag 'random-5.19-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
"These updates continue to refine the work began in 5.17 and 5.18 of
modernizing the RNG's crypto and streamlining and documenting its
code.
New for 5.19, the updates aim to improve entropy collection methods
and make some initial decisions regarding the "premature next" problem
and our threat model. The cloc utility now reports that random.c is
931 lines of code and 466 lines of comments, not that basic metrics
like that mean all that much, but at the very least it tells you that
this is very much a manageable driver now.
Here's a summary of the various updates:
- The random_get_entropy() function now always returns something at
least minimally useful. This is the primary entropy source in most
collectors, which in the best case expands to something like RDTSC,
but prior to this change, in the worst case it would just return 0,
contributing nothing. For 5.19, additional architectures are wired
up, and architectures that are entirely missing a cycle counter now
have a generic fallback path, which uses the highest resolution
clock available from the timekeeping subsystem.
Some of those clocks can actually be quite good, despite the CPU
not having a cycle counter of its own, and going off-core for a
stamp is generally thought to increase jitter, something positive
from the perspective of entropy gathering. Done very early on in
the development cycle, this has been sitting in next getting some
testing for a while now and has relevant acks from the archs, so it
should be pretty well tested and fine, but is nonetheless the thing
I'll be keeping my eye on most closely.
- Of particular note with the random_get_entropy() improvements is
MIPS, which, on CPUs that lack the c0 count register, will now
combine the high-speed but short-cycle c0 random register with the
lower-speed but long-cycle generic fallback path.
- With random_get_entropy() now always returning something useful,
the interrupt handler now collects entropy in a consistent
construction.
- Rather than comparing two samples of random_get_entropy() for the
jitter dance, the algorithm now tests many samples, and uses the
amount of differing ones to determine whether or not jitter entropy
is usable and how laborious it must be. The problem with comparing
only two samples was that if the cycle counter was extremely slow,
but just so happened to be on the cusp of a change, the slowness
wouldn't be detected. Taking many samples fixes that to some
degree.
This, combined with the other improvements to random_get_entropy(),
should make future unification of /dev/random and /dev/urandom
maybe more possible. At the very least, were we to attempt it again
today (we're not), it wouldn't break any of Guenter's test rigs
that broke when we tried it with 5.18. So, not today, but perhaps
down the road, that's something we can revisit.
- We attempt to reseed the RNG immediately upon waking up from system
suspend or hibernation, making use of the various timestamps about
suspend time and such available, as well as the usual inputs such
as RDRAND when available.
- Batched randomness now falls back to ordinary randomness before the
RNG is initialized. This provides more consistent guarantees to the
types of random numbers being returned by the various accessors.
- The "pre-init injection" code is now gone for good. I suspect you
in particular will be happy to read that, as I recall you
expressing your distaste for it a few months ago. Instead, to avoid
a "premature first" issue, while still allowing for maximal amount
of entropy availability during system boot, the first 128 bits of
estimated entropy are used immediately as it arrives, with the next
128 bits being buffered. And, as before, after the RNG has been
fully initialized, it winds up reseeding anyway a few seconds later
in most cases. This resulted in a pretty big simplification of the
initialization code and let us remove various ad-hoc mechanisms
like the ugly crng_pre_init_inject().
- The RNG no longer pretends to handle the "premature next" security
model, something that various academics and other RNG designs have
tried to care about in the past. After an interesting mailing list
thread, these issues are thought to be a) mainly academic and not
practical at all, and b) actively harming the real security of the
RNG by delaying new entropy additions after a potential compromise,
making a potentially bad situation even worse. As well, in the
first place, our RNG never even properly handled the premature next
issue, so removing an incomplete solution to a fake problem was
particularly nice.
This allowed for numerous other simplifications in the code, which
is a lot cleaner as a consequence. If you didn't see it before,
https://lore.kernel.org/lkml/YmlMGx6+uigkGiZ0@zx2c4.com/ may be a
thread worth skimming through.
- While the interrupt handler received a separate code path years ago
that avoids locks by using per-cpu data structures and a faster
mixing algorithm, in order to reduce interrupt latency, input and
disk events that are triggered in hardirq handlers were still
hitting locks and more expensive algorithms. Those are now
redirected to use the faster per-cpu data structures.
- Rather than having the fake-crypto almost-siphash-based random32
implementation be used right and left, and in many places where
cryptographically secure randomness is desirable, the batched
entropy code is now fast enough to replace that.
- As usual, numerous code quality and documentation cleanups. For
example, the initialization state machine now uses enum symbolic
constants instead of just hard coding numbers everywhere.
- Since the RNG initializes once, and then is always initialized
thereafter, a pretty heavy amount of code used during that
initialization is never used again. It is now completely cordoned
off using static branches and it winds up in the .text.unlikely
section so that it doesn't reduce cache compactness after the RNG
is ready.
- A variety of functions meant for waiting on the RNG to be
initialized were only used by vsprintf, and in not a particularly
optimal way. Replacing that usage with a more ordinary setup made
it possible to remove those functions.
- A cleanup of how we warn userspace about the use of uninitialized
/dev/urandom and uninitialized get_random_bytes() usage.
Interestingly, with the change you merged for 5.18 that attempts to
use jitter (but does not block if it can't), the majority of users
should never see those warnings for /dev/urandom at all now, and
the one for in-kernel usage is mainly a debug thing.
- The file_operations struct for /dev/[u]random now implements
.read_iter and .write_iter instead of .read and .write, allowing it
to also implement .splice_read and .splice_write, which makes
splice(2) work again after it was broken here (and in many other
places in the tree) during the set_fs() removal. This was a bit of
a last minute arrival from Jens that hasn't had as much time to
bake, so I'll be keeping my eye on this as well, but it seems
fairly ordinary. Unfortunately, read_iter() is around 3% slower
than read() in my tests, which I'm not thrilled about. But Jens and
Al, spurred by this observation, seem to be making progress in
removing the bottlenecks on the iter paths in the VFS layer in
general, which should remove the performance gap for all drivers.
- Assorted other bug fixes, cleanups, and optimizations.
- A small SipHash cleanup"
* tag 'random-5.19-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (49 commits)
random: check for signals after page of pool writes
random: wire up fops->splice_{read,write}_iter()
random: convert to using fops->write_iter()
random: convert to using fops->read_iter()
random: unify batched entropy implementations
random: move randomize_page() into mm where it belongs
random: remove mostly unused async readiness notifier
random: remove get_random_bytes_arch() and add rng_has_arch_random()
random: move initialization functions out of hot pages
random: make consistent use of buf and len
random: use proper return types on get_random_{int,long}_wait()
random: remove extern from functions in header
random: use static branch for crng_ready()
random: credit architectural init the exact amount
random: handle latent entropy and command line from random_init()
random: use proper jiffies comparison macro
random: remove ratelimiting for in-kernel unseeded randomness
random: move initialization out of reseeding hot path
random: avoid initializing twice in credit race
random: use symbolic constants for crng_init states
...
|
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|
Linus Torvalds
|
6e01f86fb2 |
Updates for timers and timekeeping core code:
- Expose CLOCK_TAI to instrumentation to aid with TSN debugging.
- Ensure that the clockevent is stopped when there is no timer armed to
avoid pointless wakeups.
- Make the sched clock frequency handling and rounding consistent.
- Provide a better debugobject hint for delayed works. The timer callback
is always the same, which makes it difficult to identify the underlying
work. Use the work function as a hint instead.
- Move the timer specific sysctl code into the timer subsystem.
- The usual set of improvements and cleanups
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Merge tag 'timers-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer and timekeeping updates from Thomas Gleixner:
- Expose CLOCK_TAI to instrumentation to aid with TSN debugging.
- Ensure that the clockevent is stopped when there is no timer armed to
avoid pointless wakeups.
- Make the sched clock frequency handling and rounding consistent.
- Provide a better debugobject hint for delayed works. The timer
callback is always the same, which makes it difficult to identify the
underlying work. Use the work function as a hint instead.
- Move the timer specific sysctl code into the timer subsystem.
- The usual set of improvements and cleanups
* tag 'timers-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Provide a better debugobjects hint for delayed works
time/sched_clock: Fix formatting of frequency reporting code
time/sched_clock: Use Hz as the unit for clock rate reporting below 4kHz
time/sched_clock: Round the frequency reported to nearest rather than down
timekeeping: Consolidate fast timekeeper
timekeeping: Annotate ktime_get_boot_fast_ns() with data_race()
timers/nohz: Switch to ONESHOT_STOPPED in the low-res handler when the tick is stopped
timekeeping: Introduce fast accessor to clock tai
tracing/timer: Add missing argument documentation of trace points
clocksource: Replace cpumask_weight() with cpumask_empty()
timers: Move timer sysctl into the timer code
clockevents: Use dedicated list iterator variable
timers: Simplify calc_index()
timers: Initialize base::next_expiry_recalc in timers_prepare_cpu()
|
||
|
Jason A. Donenfeld
|
d4150779e6 |
random32: use real rng for non-deterministic randomness
random32.c has two random number generators in it: one that is meant to be used deterministically, with some predefined seed, and one that does the same exact thing as random.c, except does it poorly. The first one has some use cases. The second one no longer does and can be replaced with calls to random.c's proper random number generator. The relatively recent siphash-based bad random32.c code was added in response to concerns that the prior random32.c was too deterministic. Out of fears that random.c was (at the time) too slow, this code was anonymously contributed. Then out of that emerged a kind of shadow entropy gathering system, with its own tentacles throughout various net code, added willy nilly. Stop👏making👏bespoke👏random👏number👏generators👏. Fortunately, recent advances in random.c mean that we can stop playing with this sketchiness, and just use get_random_u32(), which is now fast enough. In micro benchmarks using RDPMC, I'm seeing the same median cycle count between the two functions, with the mean being _slightly_ higher due to batches refilling (which we can optimize further need be). However, when doing *real* benchmarks of the net functions that actually use these random numbers, the mean cycles actually *decreased* slightly (with the median still staying the same), likely because the additional prandom code means icache misses and complexity, whereas random.c is generally already being used by something else nearby. The biggest benefit of this is that there are many users of prandom who probably should be using cryptographically secure random numbers. This makes all of those accidental cases become secure by just flipping a switch. Later on, we can do a tree-wide cleanup to remove the static inline wrapper functions that this commit adds. There are also some low-ish hanging fruits for making this even faster in the future: a get_random_u16() function for use in the networking stack will give a 2x performance boost there, using SIMD for ChaCha20 will let us compute 4 or 8 or 16 blocks of output in parallel, instead of just one, giving us large buffers for cheap, and introducing a get_random_*_bh() function that assumes irqs are already disabled will shave off a few cycles for ordinary calls. These are things we can chip away at down the road. Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
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Stephen Boyd
|
317f29c14d |
timers: Provide a better debugobjects hint for delayed works
With debugobjects enabled the timer hint for freeing of active timers embedded inside delayed works is always the same, i.e. the hint is delayed_work_timer_fn, even though the function the delayed work is going to run can be wildly different depending on what work was queued. Enabling workqueue debugobjects doesn't help either because the delayed work isn't considered active until it is actually queued to run on a workqueue. If the work is freed while the timer is pending the work isn't considered active so there is no information from workqueue debugobjects. Special case delayed works in the timer debugobjects hint logic so that the delayed work function is returned instead of the delayed_work_timer_fn. This will help to understand which delayed work was pending that got freed. Apply the same treatment for kthread_delayed_work because it follows the same pattern. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220511201951.42408-1-swboyd@chromium.org |
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Jason A. Donenfeld
|
1366992e16 |
timekeeping: Add raw clock fallback for random_get_entropy()
The addition of random_get_entropy_fallback() provides access to whichever time source has the highest frequency, which is useful for gathering entropy on platforms without available cycle counters. It's not necessarily as good as being able to quickly access a cycle counter that the CPU has, but it's still something, even when it falls back to being jiffies-based. In the event that a given arch does not define get_cycles(), falling back to the get_cycles() default implementation that returns 0 is really not the best we can do. Instead, at least calling random_get_entropy_fallback() would be preferable, because that always needs to return _something_, even falling back to jiffies eventually. It's not as though random_get_entropy_fallback() is super high precision or guaranteed to be entropic, but basically anything that's not zero all the time is better than returning zero all the time. Finally, since random_get_entropy_fallback() is used during extremely early boot when randomizing freelists in mm_init(), it can be called before timekeeping has been initialized. In that case there really is nothing we can do; jiffies hasn't even started ticking yet. So just give up and return 0. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Theodore Ts'o <tytso@mit.edu> |
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|
Eric W. Biederman
|
e71ba12407 |
signal: Replace __group_send_sig_info with send_signal_locked
The function __group_send_sig_info is just a light wrapper around send_signal_locked with one parameter fixed to a constant value. As the wrapper adds no real value update the code to directly call the wrapped function. Tested-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20220505182645.497868-2-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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Maciej W. Rozycki
|
f4b62e1e11 |
time/sched_clock: Fix formatting of frequency reporting code
Use flat rather than nested indentation for chained else/if clauses as
per coding-style.rst:
if (x == y) {
..
} else if (x > y) {
...
} else {
....
}
This also improves readability.
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240148220.9383@angie.orcam.me.uk
|
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|
Maciej W. Rozycki
|
cc1b923a4e |
time/sched_clock: Use Hz as the unit for clock rate reporting below 4kHz
The kernel uses kHz as the unit for clock rates reported between 1MHz (inclusive) and 4MHz (exclusive), e.g.: sched_clock: 64 bits at 1000kHz, resolution 1000ns, wraps every 2199023255500ns This reduces the amount of data lost due to rounding, but hasn't been replicated for the kHz range when support was added for proper reporting of sub-kHz clock rates. Take the same approach for rates between 1kHz (inclusive) and 4kHz (exclusive), which makes it consistent. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240106380.9383@angie.orcam.me.uk |
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Maciej W. Rozycki
|
92067440f1 |
time/sched_clock: Round the frequency reported to nearest rather than down
The frequency reported for clock sources are rounded down, which gives misleading figures, e.g.: I/O ASIC clock frequency 24999480Hz sched_clock: 32 bits at 24MHz, resolution 40ns, wraps every 85901132779ns MIPS counter frequency 59998512Hz sched_clock: 32 bits at 59MHz, resolution 16ns, wraps every 35792281591ns Rounding to nearest is more adequate: I/O ASIC clock frequency 24999664Hz sched_clock: 32 bits at 25MHz, resolution 40ns, wraps every 85900499947ns MIPS counter frequency 59999728Hz sched_clock: 32 bits at 60MHz, resolution 16ns, wraps every 35791556599ns Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <jstultz@google.com> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204240055590.9383@angie.orcam.me.uk |
||
|
Thomas Gleixner
|
90be8d6c1f |
timekeeping: Consolidate fast timekeeper
Provide a inline function which replaces the copy & pasta. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220415091921.072296632@linutronix.de |
||
|
Thomas Gleixner
|
eff4849f92 |
timekeeping: Annotate ktime_get_boot_fast_ns() with data_race()
Accessing timekeeper::offset_boot in ktime_get_boot_fast_ns() is an intended data race as the reader side cannot synchronize with a writer and there is no space in struct tk_read_base of the NMI safe timekeeper. Mark it so. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220415091920.956045162@linutronix.de |
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Kurt Kanzenbach
|
2c33d775ef |
timekeeping: Mark NMI safe time accessors as notrace
Mark the CLOCK_MONOTONIC fast time accessors as notrace. These functions are used in tracing to retrieve timestamps, so they should not recurse. Fixes: |
||
|
Nicholas Piggin
|
62c1256d54 |
timers/nohz: Switch to ONESHOT_STOPPED in the low-res handler when the tick is stopped
When tick_nohz_stop_tick() stops the tick and high resolution timers are disabled, then the clock event device is not put into ONESHOT_STOPPED mode. This can lead to spurious timer interrupts with some clock event device drivers that don't shut down entirely after firing. Eliminate these by putting the device into ONESHOT_STOPPED mode at points where it is not being reprogrammed. When there are no timers active, then tick_program_event() with KTIME_MAX can be used to stop the device. When there is a timer active, the device can be stopped at the next tick (any new timer added by timers will reprogram the tick). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220422141446.915024-1-npiggin@gmail.com |
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Thomas Gleixner
|
ce8abf340e |
Provide the NMI safe accessor to clock TAI for the tracing tree.
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||
|
Kurt Kanzenbach
|
3dc6ffae2d |
timekeeping: Introduce fast accessor to clock tai
Introduce fast/NMI safe accessor to clock tai for tracing. The Linux kernel tracing infrastructure has support for using different clocks to generate timestamps for trace events. Especially in TSN networks it's useful to have TAI as trace clock, because the application scheduling is done in accordance to the network time, which is based on TAI. With a tai trace_clock in place, it becomes very convenient to correlate network activity with Linux kernel application traces. Use the same implementation as ktime_get_boot_fast_ns() does by reading the monotonic time and adding the TAI offset. The same limitations as for the fast boot implementation apply. The TAI offset may change at run time e.g., by setting the time or using adjtimex() with an offset. However, these kind of offset changes are rare events. Nevertheless, the user has to be aware and deal with it in post processing. An alternative approach would be to use the same implementation as ktime_get_real_fast_ns() does. However, this requires to add an additional u64 member to the tk_read_base struct. This struct together with a seqcount is designed to fit into a single cache line on 64 bit architectures. Adding a new member would violate this constraint. Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20220414091805.89667-2-kurt@linutronix.de |
||
|
Yury Norov
|
8afbcaf869 |
clocksource: Replace cpumask_weight() with cpumask_empty()
clocksource_verify_percpu() calls cpumask_weight() to check if any bit of a given cpumask is set. This can be done more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220210224933.379149-24-yury.norov@gmail.com |
||
|
tangmeng
|
efaa0227f6 |
timers: Move timer sysctl into the timer code
This is part of the effort to reduce kernel/sysctl.c to only contain the core logic. Signed-off-by: tangmeng <tangmeng@uniontech.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220215065019.7520-1-tangmeng@uniontech.com |
||
|
Jakob Koschel
|
2966a9918d |
clockevents: Use dedicated list iterator variable
To move the list iterator variable into the list_for_each_entry_*() macro in the future it should be avoided to use the list iterator variable after the loop body. To *never* use the list iterator variable after the loop it was concluded to use a separate iterator variable. Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ Link: https://lore.kernel.org/r/20220331215707.883957-1-jakobkoschel@gmail.com |
||
|
Jiapeng Chong
|
9c95bc25ad |
tick/sched: Fix non-kernel-doc comment
Fixes the following W=1 kernel build warning: kernel/time/tick-sched.c:1563: warning: This comment starts with '/**', but isn't a kernel-doc comment. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220214084739.63228-1-jiapeng.chong@linux.alibaba.com |
||
|
Paul Gortmaker
|
40e97e4296 |
tick/nohz: Use WARN_ON_ONCE() to prevent console saturation
While running some testing on code that happened to allow the variable
tick_nohz_full_running to get set but with no "possible" NOHZ cores to
back up that setting, this warning triggered:
if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
WARN_ON(tick_nohz_full_running);
The console was overwhemled with an endless stream of one WARN per tick
per core and there was no way to even see what was going on w/o using a
serial console to capture it and then trace it back to this.
Change it to WARN_ON_ONCE().
Fixes:
|
||
|
Thomas Gleixner
|
a2026e44ef |
timers: Simplify calc_index()
The level granularity round up of calc_index() does: (x + (1 << n)) >> n which is obviously equivalent to (x >> n) + 1 but compilers can't figure that out despite the fact that the input range is known to not cause an overflow. It's neither intuitive to read. Just write out the obvious. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/87h778j46c.ffs@tglx |
||
|
Anna-Maria Behnsen
|
2731aa7d65 |
timers: Initialize base::next_expiry_recalc in timers_prepare_cpu()
When base::next_expiry_recalc is not initialized to false during cpu bringup in HOTPLUG_CPU and is accidently true and no timer is queued in the meantime, the loop through the wheel to find __next_timer_interrupt() might be done for nothing. Therefore initialize base::next_expiry_recalc to false in timers_prepare_cpu(). Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20220405191732.7438-2-anna-maria@linutronix.de |
||
|
Anna-Maria Behnsen
|
c54bc0fc84 |
timers: Fix warning condition in __run_timers()
When the timer base is empty, base::next_expiry is set to base::clk +
NEXT_TIMER_MAX_DELTA and base::next_expiry_recalc is false. When no timer
is queued until jiffies reaches base::next_expiry value, the warning for
not finding any expired timer and base::next_expiry_recalc is false in
__run_timers() triggers.
To prevent triggering the warning in this valid scenario
base::timers_pending needs to be added to the warning condition.
Fixes:
|
||
|
Linus Torvalds
|
1930a6e739 |
ptrace: Cleanups for v5.18
This set of changes removes tracehook.h, moves modification of all of
the ptrace fields inside of siglock to remove races, adds a missing
permission check to ptrace.c
The removal of tracehook.h is quite significant as it has been a major
source of confusion in recent years. Much of that confusion was
around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled
making the semantics clearer).
For people who don't know tracehook.h is a vestiage of an attempt to
implement uprobes like functionality that was never fully merged, and
was later superseeded by uprobes when uprobes was merged. For many
years now we have been removing what tracehook functionaly a little
bit at a time. To the point where now anything left in tracehook.h is
some weird strange thing that is difficult to understand.
Eric W. Biederman (15):
ptrace: Move ptrace_report_syscall into ptrace.h
ptrace/arm: Rename tracehook_report_syscall report_syscall
ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
ptrace: Remove arch_syscall_{enter,exit}_tracehook
ptrace: Remove tracehook_signal_handler
task_work: Remove unnecessary include from posix_timers.h
task_work: Introduce task_work_pending
task_work: Call tracehook_notify_signal from get_signal on all architectures
task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
resume_user_mode: Move to resume_user_mode.h
tracehook: Remove tracehook.h
ptrace: Move setting/clearing ptrace_message into ptrace_stop
ptrace: Return the signal to continue with from ptrace_stop
Jann Horn (1):
ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
Yang Li (1):
ptrace: Remove duplicated include in ptrace.c
MAINTAINERS | 1 -
arch/Kconfig | 5 +-
arch/alpha/kernel/ptrace.c | 5 +-
arch/alpha/kernel/signal.c | 4 +-
arch/arc/kernel/ptrace.c | 5 +-
arch/arc/kernel/signal.c | 4 +-
arch/arm/kernel/ptrace.c | 12 +-
arch/arm/kernel/signal.c | 4 +-
arch/arm64/kernel/ptrace.c | 14 +--
arch/arm64/kernel/signal.c | 4 +-
arch/csky/kernel/ptrace.c | 5 +-
arch/csky/kernel/signal.c | 4 +-
arch/h8300/kernel/ptrace.c | 5 +-
arch/h8300/kernel/signal.c | 4 +-
arch/hexagon/kernel/process.c | 4 +-
arch/hexagon/kernel/signal.c | 1 -
arch/hexagon/kernel/traps.c | 6 +-
arch/ia64/kernel/process.c | 4 +-
arch/ia64/kernel/ptrace.c | 6 +-
arch/ia64/kernel/signal.c | 1 -
arch/m68k/kernel/ptrace.c | 5 +-
arch/m68k/kernel/signal.c | 4 +-
arch/microblaze/kernel/ptrace.c | 5 +-
arch/microblaze/kernel/signal.c | 4 +-
arch/mips/kernel/ptrace.c | 5 +-
arch/mips/kernel/signal.c | 4 +-
arch/nds32/include/asm/syscall.h | 2 +-
arch/nds32/kernel/ptrace.c | 5 +-
arch/nds32/kernel/signal.c | 4 +-
arch/nios2/kernel/ptrace.c | 5 +-
arch/nios2/kernel/signal.c | 4 +-
arch/openrisc/kernel/ptrace.c | 5 +-
arch/openrisc/kernel/signal.c | 4 +-
arch/parisc/kernel/ptrace.c | 7 +-
arch/parisc/kernel/signal.c | 4 +-
arch/powerpc/kernel/ptrace/ptrace.c | 8 +-
arch/powerpc/kernel/signal.c | 4 +-
arch/riscv/kernel/ptrace.c | 5 +-
arch/riscv/kernel/signal.c | 4 +-
arch/s390/include/asm/entry-common.h | 1 -
arch/s390/kernel/ptrace.c | 1 -
arch/s390/kernel/signal.c | 5 +-
arch/sh/kernel/ptrace_32.c | 5 +-
arch/sh/kernel/signal_32.c | 4 +-
arch/sparc/kernel/ptrace_32.c | 5 +-
arch/sparc/kernel/ptrace_64.c | 5 +-
arch/sparc/kernel/signal32.c | 1 -
arch/sparc/kernel/signal_32.c | 4 +-
arch/sparc/kernel/signal_64.c | 4 +-
arch/um/kernel/process.c | 4 +-
arch/um/kernel/ptrace.c | 5 +-
arch/x86/kernel/ptrace.c | 1 -
arch/x86/kernel/signal.c | 5 +-
arch/x86/mm/tlb.c | 1 +
arch/xtensa/kernel/ptrace.c | 5 +-
arch/xtensa/kernel/signal.c | 4 +-
block/blk-cgroup.c | 2 +-
fs/coredump.c | 1 -
fs/exec.c | 1 -
fs/io-wq.c | 6 +-
fs/io_uring.c | 11 +-
fs/proc/array.c | 1 -
fs/proc/base.c | 1 -
include/asm-generic/syscall.h | 2 +-
include/linux/entry-common.h | 47 +-------
include/linux/entry-kvm.h | 2 +-
include/linux/posix-timers.h | 1 -
include/linux/ptrace.h | 81 ++++++++++++-
include/linux/resume_user_mode.h | 64 ++++++++++
include/linux/sched/signal.h | 17 +++
include/linux/task_work.h | 5 +
include/linux/tracehook.h | 226 -----------------------------------
include/uapi/linux/ptrace.h | 2 +-
kernel/entry/common.c | 19 +--
kernel/entry/kvm.c | 9 +-
kernel/exit.c | 3 +-
kernel/livepatch/transition.c | 1 -
kernel/ptrace.c | 47 +++++---
kernel/seccomp.c | 1 -
kernel/signal.c | 62 +++++-----
kernel/task_work.c | 4 +-
kernel/time/posix-cpu-timers.c | 1 +
mm/memcontrol.c | 2 +-
security/apparmor/domain.c | 1 -
security/selinux/hooks.c | 1 -
85 files changed, 372 insertions(+), 495 deletions(-)
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ptrace cleanups from Eric Biederman:
"This set of changes removes tracehook.h, moves modification of all of
the ptrace fields inside of siglock to remove races, adds a missing
permission check to ptrace.c
The removal of tracehook.h is quite significant as it has been a major
source of confusion in recent years. Much of that confusion was around
task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the
semantics clearer).
For people who don't know tracehook.h is a vestiage of an attempt to
implement uprobes like functionality that was never fully merged, and
was later superseeded by uprobes when uprobes was merged. For many
years now we have been removing what tracehook functionaly a little
bit at a time. To the point where anything left in tracehook.h was
some weird strange thing that was difficult to understand"
* tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ptrace: Remove duplicated include in ptrace.c
ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE
ptrace: Return the signal to continue with from ptrace_stop
ptrace: Move setting/clearing ptrace_message into ptrace_stop
tracehook: Remove tracehook.h
resume_user_mode: Move to resume_user_mode.h
resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume
signal: Move set_notify_signal and clear_notify_signal into sched/signal.h
task_work: Decouple TIF_NOTIFY_SIGNAL and task_work
task_work: Call tracehook_notify_signal from get_signal on all architectures
task_work: Introduce task_work_pending
task_work: Remove unnecessary include from posix_timers.h
ptrace: Remove tracehook_signal_handler
ptrace: Remove arch_syscall_{enter,exit}_tracehook
ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h
ptrace/arm: Rename tracehook_report_syscall report_syscall
ptrace: Move ptrace_report_syscall into ptrace.h
|
||
|
Linus Torvalds
|
cd4699c5fd |
prlimit and set/getpriority tasklist_lock optimizations
The tasklist_lock popped up as a scalability bottleneck on some testing workloads. The readlocks in do_prlimit and set/getpriority are not necessary in all cases. Based on a cycles profile, it looked like ~87% of the time was spent in the kernel, ~42% of which was just trying to get *some* spinlock (queued_spin_lock_slowpath, not necessarily the tasklist_lock). The big offenders (with rough percentages in cycles of the overall trace): - do_wait 11% - setpriority 8% (this patchset) - kill 8% - do_exit 5% - clone 3% - prlimit64 2% (this patchset) - getrlimit 1% (this patchset) I can't easily test this patchset on the original workload for various reasons. Instead, I used the microbenchmark below to at least verify there was some improvement. This patchset had a 28% speedup (12% from baseline to set/getprio, then another 14% for prlimit). One interesting thing is that my libc's getrlimit() was calling prlimit64, so hoisting the read_lock(tasklist_lock) into sys_prlimit64 had no effect - it essentially optimized the older syscalls only. I didn't do that in this patchset, but figured I'd mention it since it was an option from the previous patch's discussion. v3: https://lkml.kernel.org/r/20220106172041.522167-1-brho@google.com v2: https://lore.kernel.org/lkml/20220105212828.197013-1-brho@google.com/ - update_rlimit_cpu on the group_leader instead of for_each_thread. - update_rlimit_cpu still returns 0 or -ESRCH, even though we don't care about the error here. it felt safer that way in case someone uses that function again. v1: https://lore.kernel.org/lkml/20211213220401.1039578-1-brho@google.com/ int main(int argc, char **argv) { pid_t child; struct rlimit rlim[1]; fork(); fork(); fork(); fork(); fork(); fork(); for (int i = 0; i < 5000; i++) { child = fork(); if (child < 0) exit(1); if (child > 0) { usleep(1000); kill(child, SIGTERM); waitpid(child, NULL, 0); } else { for (;;) { setpriority(PRIO_PROCESS, 0, getpriority(PRIO_PROCESS, 0)); getrlimit(RLIMIT_CPU, rlim); } } } return 0; } Barret Rhoden (3): setpriority: only grab the tasklist_lock for PRIO_PGRP prlimit: make do_prlimit() static prlimit: do not grab the tasklist_lock include/linux/posix-timers.h | 2 +- include/linux/resource.h | 2 - kernel/sys.c | 127 +++++++++++++++++---------------- kernel/time/posix-cpu-timers.c | 12 +++- 4 files changed, 76 insertions(+), 67 deletions(-) I have dropped the first change in this series as an almost identical change was merged as commit |