Commit graph

30959 commits

Author SHA1 Message Date
Russell King
9641c7cc5a [ARM] nommu: uaccess tweaks
MMUless systems have only one address space for all threads, so
both the usual access_ok() checks, and the exception handling do
not make much sense.

Hence, discard the fixup and exception tables at link time, use
memcpy/memset for the user copy/clearing functions, and define
the permission check macros to be constants.

Some of this patch was derived from the equivalent patch by
Hyok S. Choi.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28 17:59:46 +01:00
Russell King
002547b4f8 [ARM] nommu: adjust headers for !MMU ARM systems
Majorily based on Hyok Choi's patches, this fixes up the asm-arm
header files for mmuless systems.  Over and above Hyok's patches:

- nommu.h merged into mmu.h (it's only a structure)
- nommu_context.h is essentially the same as mmu_context.h, but
  without the MM switching code.

so there's no point having separate files.  Also, in memory.h,
there's no point #ifndef'ing PHYS_OFFSET and END_MEM - both
CONFIG_DRAM_BASE and CONFIG_DRAM_SIZE will always be set by the
configuration scripts.

Other files have minor formatting changes, but are essentially
the same.  Hyok's original patches were signed off thusly:

  Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28 17:59:45 +01:00
Russell King
60b6cf6851 [ARM] nommu: we need the TLS register emulation for nommu mode
Since there can be no fixed location for the TLS value with nommu
systems, we must provide TLS register emulation in order to support
TLS binaries on CPUs without the thread register.

Part of a patch from Hyok S. Choi, and cleaned up by rmk.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28 17:59:43 +01:00
Russell King
02fcb97436 [ARM] Remove the __arch_* layer from uaccess.h
Back in the days when we had armo (26-bit) and armv (32-bit) combined,
we had an additional layer to the uaccess macros to ensure correct
typing.  Since we no longer have 26-bit in this tree, we no longer
need this layer, so eliminate it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28 17:53:27 +01:00
Linus Torvalds
a39727f212 Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6:
  [netdrvr] Remove long-unused bits from Becker template drivers
  [netdrvr] natsemi: minor cleanups
  [netdrvr] natsemi: Separate out media initialization code
  [PATCH] WAN: update info page for a bunch of my drivers
  [PATCH] drivers/net/hamradio/dmascc.c: fix section mismatch
  [PATCH] Fix phy id for LXT971A/LXT972A
  [PATCH] DM9000 - minor code cleanups
  [PATCH] DM9000 - do no re-init spin lock
  [PATCH] DM9000 - check for MAC left in by bootloader
  [PATCH] DM9000 - better checks for platform resources
2006-06-27 19:15:50 -07:00
Linus Torvalds
936813a880 Merge git://git.infradead.org/mtd-2.6
* git://git.infradead.org/mtd-2.6:
  [MTD] NAND: Select chip before checking write protect status
  [MTD] CORE mtdchar.c: fix off-by-one error in lseek()
  [MTD] NAND: Fix typo in mtd/nand/ts7250.c
  [JFFS2][XATTR] coexistence between xattr and write buffering support.
  [JFFS2][XATTR] Fix wrong copyright
  [JFFS2][XATTR] Re-define xd->refcnt as atomic_t
  [JFFS2][XATTR] Fix memory leak with jffs2_xattr_ref
  [JFFS2][XATTR] rid unnecessary writing of delete marker.
  [JFFS2][XATTR] Fix ACL bug when updating null xattr by null ACL.
  [JFFS2][XATTR] using 'delete marker' for xdatum/xref deletion
  [MTD] Fix off-by-one error in physmap.c
  [MTD] Remove unused 'nr_banks' variable from ixp2000 map driver
  [MTD NAND] s3c2412 support in s3c2410.c
  [MTD] Initialize 'writesize'
  [MTD] NAND: ndfc fix address offset thinko
  [MTD] NAND: S3C2410 convert prinks to dev_*()s
  [MTD] NAND: Missing fixups
2006-06-27 19:13:56 -07:00
Linus Torvalds
73a0e405dc Merge git://oss.sgi.com:8090/nathans/xfs-2.6
* git://oss.sgi.com:8090/nathans/xfs-2.6:
  [XFS] Fixup whitespace damage in log_write, remove final warning.
  [XFS] Rework code snippets slightly to remove remaining recent-gcc
  [XFS] Fix realtime subvolume expansion, a porting bug b0rked it.  Coverity
  [XFS] Remove a race condition where a linked inode could BUG_ON in
  [XFS] Remove redundant directory checks from inode link operation.
  [XFS] Remove a couple of no-longer-used macros.
  [XFS] Reduce size of xfs_trans_t structure. * remove ->t_forw, ->t_back --
  [XFS] remove unused behaviour lock - shrink XFS vnode as a side effect.
  [XFS] * There is trivial "inode => vnode => inode" conversion, but only
  [XFS] link(2) on directory is banned in VFS.
2006-06-27 19:09:16 -07:00
Linus Torvalds
03529d9f66 Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [PATCH] ata_piix: add ICH6/7/8 to Kconfig
  [PATCH] sata_sil: disable hotplug interrupts on two ATI IXPs
  [PATCH] libata: cosmetic updates
  [PATCH] ata: add some NVIDIA chipset IDs
  [PATCH] libata reduce timeouts
  [PATCH] libata: implement ata_port_max_devices()
  [PATCH] libata: make two functions global
  [PATCH] libata: update ata_do_simple_cmd()
  [PATCH] libata: move ata_do_simple_cmd() below ata_exec_internal()
  [PATCH] libata: clear EH action on device detach
  [PATCH] libata: implement and use ata_deh_dev_action()
  [PATCH] libata: move ata_eh_clear_action() upward
  [PATCH] libata.h needs scatterlist.h
  [libata] sata_vsc: partially revert a PCI ID-related commit
  [libata] Bump versions
2006-06-27 19:07:21 -07:00
Linus Torvalds
11bcab9071 Properly delete sound/ppc/toonie.c
The previous "delete" had actually just truncated it to a zero
size, something that can easily happen if you just apply a patch.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:47:50 -07:00
Daniel Ritz
d6fcb3b9cf [PATCH] i2c-i801.c: don't pci_disable_device() after it was just enabled
Commit 02dd7ae289 ("[PATCH] i2c-i801:
Merge setup function") has a missing return 0 in the _probe() function.
This means the error path is always executed and pci_disable_device() is
called even when the device just got successfully enabled.

Having the SMBus device disabled makes some systems (eg.
Fujitsu-Siemens Lifebook E8010) hang hard during power-off.

Intead of reverting the whole commit this patch fixes it up:
- don't ever call pci_disable_device(), also not in the _remove() function
  to avoid hangs
- fix missing pci_release_region() in error path

Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:36:39 -07:00
Linus Torvalds
f17a2686b1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (25 commits)
  [CIFS] Fix authentication choice so we do not force NTLMv2 unless the
  [CIFS] Fix alignment of unicode strings in previous patch
  [CIFS] Fix allocation of buffers for new session setup routine to allow
  [CIFS] Remove calls to to take f_owner.lock
  [CIFS] remove some redundant null pointer checks
  [CIFS] Fix compile warning when CONFIG_CIFS_EXPERIMENTAL is off
  [CIFS] Enable sec flags on mount for cifs (part one)
  [CIFS] Fix suspend/resume problem which causes EIO on subsequent access to
  [CIFS] fix minor compile warning when config_cifs_weak_security is off
  [CIFS] NTLMv2 support part 5
  [CIFS] Add support for readdir to legacy servers
  [CIFS] NTLMv2 support part 4
  [CIFS] NTLMv2 support part 3
  [CIFS] NTLMv2 support part 2
  [CIFS] Fix mask so can set new cifs security flags properly
  CIFS] Support for older servers which require plaintext passwords - part 2
  [CIFS] Support for older servers which require plaintext passwords
  [CIFS] Fix mapping of old SMB return code Invalid Net Name so it is
  [CIFS] Missing brace
  [CIFS] Do not overwrite aops
  ...
2006-06-27 18:31:57 -07:00
Greg Ungerer
01f7e67367 [PATCH] m68knommu: use Kconfig RAM config options in 68328 startup code
Switch to using the new RAM Kconfig settings, instead of linker defined
regions in ROM specific 68328 startup code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:30:14 -07:00
Greg Ungerer
f5c7726ffc [PATCH] m68knommu: use Kconfig RAM config options in 68360 ROM startup code
Switch to using the new RAM Kconfig settings, instead of linker defined
regions in ROM specific 68360 startup code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:30:14 -07:00
Greg Ungerer
d046f6118b [PATCH] m68knommu: use Kconfig RAM config options in 68360 RAM startup code
Switch to using the new RAM Kconfig settings, instead of linker defined
regions in RAM specific 68360 startup code.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:30:14 -07:00
Greg Ungerer
999567d829 [PATCH] m68knommu: remove NO_FORMAT_VECi from ptrace.h header
Remove NO_FORMAT_VEC conditional check. It is not used or defined anywhere.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:30:14 -07:00
Greg Ungerer
0e702ab38b [PATCH] m68knommu: FEC driver event/irq fixes
Collection of fixes for the ColdFire FEC ethernet driver:

. reworked event setting so that it occurs after the MII setup.
  roucaries bastien <roucaries.bastien@gmail.com>
. Do not read cbd_sc in memory for each bit we test. Once per buffer is enough.
. Overrun errors must increase `rx_fifo_errors', not `rx_crc_errors'
. No need for a special value to activate rx or tx.  Only write access matters.
. Simplify parameter of eth_copy_and_sum : `data' has already the right value.
. Some spelling fixes.

Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:30:14 -07:00
Willson Callan
83901fc1c7 [PATCH] m68knommu: FEC driver set different priority/level on each IRQ
Set different irq priority levels for each IRQ requested.
According to the Freescale ColdFire documentation each separate IRQ
must have its own unique priority/level combination.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:37 -07:00
Matt Waddel
6b2652936b [PATCH] m68knommu: FEC driver support for the ColdFire 523x CPU family
Add support for the FEC module in the ColdFire 532x CPU family.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:37 -07:00
Philippe De Muyter
677177c531 [PATCH] m68knommu: avoid fec driver hang when link disappears
Avoid requesting a `Graceful Transmit Stop' when link has disappeared,
because that request cannot complete without link.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:37 -07:00
Greg Ungerer
67bdd98424 [PATCH] m68knommu: update m68knommu defconfnig
Updated defconfig for m68knommu arch. Includes recent changes to the clock
and RAM configuration options.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:37 -07:00
Matt Waddel
9a6404b4d9 [PATCH] m68knommu: build support for the Freescale 532x CPU family
Add build support for the M523x ColdFire CPU family.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:36 -07:00
Daniel Alomar
121036e5c5 [PATCH] m68knommu: build support for the Avnet/5282 board
Add support for the Avnet/5282 board.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:36 -07:00
Philipe De Muyter
3f787bff45 [PATCH] m68knommu: remove useless compiler args
Here is a small patch that made my kernel .text segment shrink by 8k IIRC
on my 5272-based board, by removing `-Wa,-S' from CFLAGS.

The `-Wa,-S' option prevents `gas' from using short forms of jsr.
Without it, `gas' replaces `jsr xxx.l' (6 bytes) by `jsr xxx@pc'
(4 bytes) when possible.  On 5272, both forms are equally fast.

The `-Wa,-m5307' option is useless, because gcc already gives it
to `gas' from the `-m5307' option.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:26:36 -07:00
James Bottomley
3c101cf024 [PATCH] voyager: add cpu_present_map
Voyager stopped booting some time in the 2.6.16-2.6.17 timeframe;
the reason was that it doesn't have a cpu_present_map, so add
one.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:25:03 -07:00
Linus Torvalds
12e56b601f Merge master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb
* master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (26 commits)
  V4L/DVB (4263): Fix warning when compiling on 64 bit machines
  V4L/DVB (4261): Included required header for in-kernel compilation
  V4L/DVB (4260): Stradis.c: make 2 functions static
  V4L/DVB (4259): Pass an explicit log prefix to cx2341x_log_status
  V4L/DVB (4257): Fix 64-bit compile warnings.
  V4L/DVB (4255): Tda9887 default TOP value is 0x10
  V4L/DVB (4254): Remove obsoleted tuner_debug option.
  V4L/DVB (4253): IVTV VBI format description too long.
  V4L/DVB (4252): Remove duplicate 'tda9887' in info messages.
  V4L/DVB (4245): Reduce the amount of pvrusb2-sourced noise going into the system log
  V4L/DVB (4244): Implement use of cx2341x module in pvrusb2 driver
  V4L/DVB (4243): Exploit new V4L control features in pvrusb2
  V4L/DVB (4242): Don't suspend encoder when changing its attributes (in pvrusb2)
  V4L/DVB (4241): Fix faulty encoder error recovery in pvrusb2
  V4L/DVB (4240): Various V4L control enhancements in pvrusb2
  V4L/DVB (4239): Handle boolean controls in pvrusb2
  V4L/DVB (4238): Make sure flags field is initialized when quering a control in pvrusb2
  V4L/DVB (4237): Move LOG_STATUS bracketing to a different part of the pvrusb2 driver
  V4L/DVB (4236): Rearrange things in pvrusb2 driver in preparation for using cx2341x module
  V4L/DVB (4235): Increase the maximum number of controls that pvrusb2-sysfs.c can handle.
  ...
2006-06-27 18:22:13 -07:00
Nathan Scott
5493a0fcba [XFS] Fixup whitespace damage in log_write, remove final warning.
SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:26366a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-28 11:17:28 +10:00
Karsten Keil
ca6f8792bd [PATCH] i4l fix DLE masking in isdn_tty_try_read
DLE masking was non-functional since the new tty handling.

Found by Peter Evertz <leo2@pec.homeip.net>

Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 18:00:36 -07:00
Andrew Morton
91bf460269 [PATCH] do_IRQ() warning fix
arch/i386/kernel/irq.c: In function 'do_IRQ':
arch/i386/kernel/irq.c:104: warning: suggest parentheses around arithmetic in operand of |

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Adrian Bunk
775d584c63 [PATCH] drivers/message/i2o/iop.c: unexport i2o_msg_nop()
It's available in a header as a static inline - there's no need to export it.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Adrian Bunk
456229a91d [PATCH] drivers/char/ipmi/ipmi_msghandler.c: make proc_ipmi_root static
Make struct proc_ipmi_root static.

Besides this, tremove removes an unused #ifdef CONFIG_PROC_FS from
include/linux/ipmi.h.

Acked-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Jesper Juhl
8f76078037 [PATCH] Remove redundant NULL checks before [kv]free - in drivers/
Remove redundant NULL chck before kfree + tiny CodingStyle cleanup for
drivers/

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Jesper Juhl
9a66a53f55 [PATCH] Remove redundant NULL checks before [kv]free - in kernel/
Remove redundant kfree NULL checks from kernel/

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Jesper Juhl
4ad98457aa [PATCH] Remove redundant NULL checks before [kv]free - in fs/
Remove redundant NULL checks before kfree for fs/

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Sebastien Dugue
59e0e0ace7 [PATCH] futex_requeue() optimization
In futex_requeue(), when the 2 futexes keys hash to the same bucket, there
is no need to move the futex_q to the end of the bucket list.

Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Thomas Gleixner
95e02ca9bb [PATCH] rtmutex: Propagate priority settings into PI lock chains
When the priority of a task, which is blocked on a lock, changes we must
propagate this change into the PI lock chain.  Therefor the chain walk code
is changed to get rid of the references to current to avoid false positives
in the deadlock detector, as setscheduler might be called by a task which
holds the lock on which the task whose priority is changed is blocked.

Also add some comments about the get/put_task_struct usage to avoid
confusion.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:48 -07:00
Thomas Gleixner
0bafd214e4 [PATCH] rtmutex: Modify rtmutex-tester to test the setscheduler propagation
Make test suite setscheduler calls asynchronously.  Remove the waits in the
test cases and add a new testcase to verify the correctness of the
setscheduler priority propagation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Thomas Gleixner
e74c69f46d [PATCH] Drop tasklist lock in do_sched_setscheduler
There is no need to hold tasklist_lock across the setscheduler call, when
we pin the task structure with get_task_struct().  Interrupts are disabled
in setscheduler anyway and the permission checks do not need interrupts
disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Roman Zippel
a1583d3e83 [PATCH] fix rt-mutex defaults and dependencies
Fix defaults and dependencies.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Ingo Molnar
c87e2837be [PATCH] pi-futex: futex_lock_pi/futex_unlock_pi support
This adds the actual pi-futex implementation, based on rt-mutexes.

[dino@in.ibm.com: fix an oops-causing race]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Ingo Molnar
0cdbee9920 [PATCH] pi-futex: rt mutex futex api
Add proxy-locking rt-mutex functionality needed by pi-futexes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Thomas Gleixner
61a8712286 [PATCH] pi-futex: rt mutex tester
RT-mutex tester: scriptable tester for rt mutexes, which allows userspace
scripting of mutex unit-tests (and dynamic tests as well), using the actual
rt-mutex implementation of the kernel.

[akpm@osdl.org: fixlet]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Ingo Molnar
e7eebaf6a8 [PATCH] pi-futex: rt mutex debug
Runtime debugging functionality for rt-mutexes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Steven Rostedt
a6537be932 [PATCH] pi-futex: rt mutex docs
Add rt-mutex documentation.

[rostedt@goodmis.org: Update rt-mutex-design.txt as per Randy Dunlap suggestions]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Ingo Molnar
23f78d4a03 [PATCH] pi-futex: rt mutex core
Core functions for the rt-mutex subsystem.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:47 -07:00
Ingo Molnar
b29739f902 [PATCH] pi-futex: scheduler support for pi
Add framework to boost/unboost the priority of RT tasks.

This consists of:

 - caching the 'normal' priority in ->normal_prio
 - providing a functions to set/get the priority of the task
 - make sched_setscheduler() aware of boosting

The effective_prio() cleanups also fix a priority-calculation bug pointed out
by Andrey Gelman, in set_user_nice().

has_rt_policy() fix: Peter Williams <pwil3058@bigpond.net.au>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andrey Gelman <agelman@012.net.il>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:46 -07:00
Ingo Molnar
77ba89c5cf [PATCH] pi-futex: add plist implementation
Add the priority-sorted list (plist) implementation.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:46 -07:00
Ingo Molnar
8eb94f80dd [PATCH] pi-futex: introduce WARN_ON_SMP
Introduce a new WARN_ON variant: WARN_ON_SMP(cond).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:46 -07:00
Ingo Molnar
f9b8404cf8 [PATCH] pi-futex: introduce debug_check_no_locks_freed()
Add debug_check_no_locks_freed(), as a central inline to add
bad-lock-free-debugging functionality to.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:46 -07:00
Ingo Molnar
6abdce7680 [PATCH] pi-futex: robust futex docs fix
Fix typo in Documentation/robust-futexes.txt.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:46 -07:00
Ingo Molnar
e2970f2fb6 [PATCH] pi-futex: futex code cleanups
We are pleased to announce "lightweight userspace priority inheritance" (PI)
support for futexes.  The following patchset and glibc patch implements it,
ontop of the robust-futexes patchset which is included in 2.6.16-mm1.

We are calling it lightweight for 3 reasons:

 - in the user-space fastpath a PI-enabled futex involves no kernel work
   (or any other PI complexity) at all.  No registration, no extra kernel
   calls - just pure fast atomic ops in userspace.

 - in the slowpath (in the lock-contention case), the system call and
   scheduling pattern is in fact better than that of normal futexes, due to
   the 'integrated' nature of FUTEX_LOCK_PI.  [more about that further down]

 - the in-kernel PI implementation is streamlined around the mutex
   abstraction, with strict rules that keep the implementation relatively
   simple: only a single owner may own a lock (i.e.  no read-write lock
   support), only the owner may unlock a lock, no recursive locking, etc.

  Priority Inheritance - why, oh why???
  -------------------------------------

Many of you heard the horror stories about the evil PI code circling Linux for
years, which makes no real sense at all and is only used by buggy applications
and which has horrible overhead.  Some of you have dreaded this very moment,
when someone actually submits working PI code ;-)

So why would we like to see PI support for futexes?

We'd like to see it done purely for technological reasons.  We dont think it's
a buggy concept, we think it's useful functionality to offer to applications,
which functionality cannot be achieved in other ways.  We also think it's the
right thing to do, and we think we've got the right arguments and the right
numbers to prove that.  We also believe that we can address all the
counter-arguments as well.  For these reasons (and the reasons outlined below)
we are submitting this patch-set for upstream kernel inclusion.

What are the benefits of PI?

  The short reply:
  ----------------

User-space PI helps achieving/improving determinism for user-space
applications.  In the best-case, it can help achieve determinism and
well-bound latencies.  Even in the worst-case, PI will improve the statistical
distribution of locking related application delays.

  The longer reply:
  -----------------

Firstly, sharing locks between multiple tasks is a common programming
technique that often cannot be replaced with lockless algorithms.  As we can
see it in the kernel [which is a quite complex program in itself], lockless
structures are rather the exception than the norm - the current ratio of
lockless vs.  locky code for shared data structures is somewhere between 1:10
and 1:100.  Lockless is hard, and the complexity of lockless algorithms often
endangers to ability to do robust reviews of said code.  I.e.  critical RT
apps often choose lock structures to protect critical data structures, instead
of lockless algorithms.  Furthermore, there are cases (like shared hardware,
or other resource limits) where lockless access is mathematically impossible.

Media players (such as Jack) are an example of reasonable application design
with multiple tasks (with multiple priority levels) sharing short-held locks:
for example, a highprio audio playback thread is combined with medium-prio
construct-audio-data threads and low-prio display-colory-stuff threads.  Add
video and decoding to the mix and we've got even more priority levels.

So once we accept that synchronization objects (locks) are an unavoidable fact
of life, and once we accept that multi-task userspace apps have a very fair
expectation of being able to use locks, we've got to think about how to offer
the option of a deterministic locking implementation to user-space.

Most of the technical counter-arguments against doing priority inheritance
only apply to kernel-space locks.  But user-space locks are different, there
we cannot disable interrupts or make the task non-preemptible in a critical
section, so the 'use spinlocks' argument does not apply (user-space spinlocks
have the same priority inversion problems as other user-space locking
constructs).  Fact is, pretty much the only technique that currently enables
good determinism for userspace locks (such as futex-based pthread mutexes) is
priority inheritance:

Currently (without PI), if a high-prio and a low-prio task shares a lock [this
is a quite common scenario for most non-trivial RT applications], even if all
critical sections are coded carefully to be deterministic (i.e.  all critical
sections are short in duration and only execute a limited number of
instructions), the kernel cannot guarantee any deterministic execution of the
high-prio task: any medium-priority task could preempt the low-prio task while
it holds the shared lock and executes the critical section, and could delay it
indefinitely.

  Implementation:
  ---------------

As mentioned before, the userspace fastpath of PI-enabled pthread mutexes
involves no kernel work at all - they behave quite similarly to normal
futex-based locks: a 0 value means unlocked, and a value==TID means locked.
(This is the same method as used by list-based robust futexes.) Userspace uses
atomic ops to lock/unlock these mutexes without entering the kernel.

To handle the slowpath, we have added two new futex ops:

  FUTEX_LOCK_PI
  FUTEX_UNLOCK_PI

If the lock-acquire fastpath fails, [i.e.  an atomic transition from 0 to TID
fails], then FUTEX_LOCK_PI is called.  The kernel does all the remaining work:
if there is no futex-queue attached to the futex address yet then the code
looks up the task that owns the futex [it has put its own TID into the futex
value], and attaches a 'PI state' structure to the futex-queue.  The pi_state
includes an rt-mutex, which is a PI-aware, kernel-based synchronization
object.  The 'other' task is made the owner of the rt-mutex, and the
FUTEX_WAITERS bit is atomically set in the futex value.  Then this task tries
to lock the rt-mutex, on which it blocks.  Once it returns, it has the mutex
acquired, and it sets the futex value to its own TID and returns.  Userspace
has no other work to perform - it now owns the lock, and futex value contains
FUTEX_WAITERS|TID.

If the unlock side fastpath succeeds, [i.e.  userspace manages to do a TID ->
0 atomic transition of the futex value], then no kernel work is triggered.

If the unlock fastpath fails (because the FUTEX_WAITERS bit is set), then
FUTEX_UNLOCK_PI is called, and the kernel unlocks the futex on the behalf of
userspace - and it also unlocks the attached pi_state->rt_mutex and thus wakes
up any potential waiters.

Note that under this approach, contrary to other PI-futex approaches, there is
no prior 'registration' of a PI-futex.  [which is not quite possible anyway,
due to existing ABI properties of pthread mutexes.]

Also, under this scheme, 'robustness' and 'PI' are two orthogonal properties
of futexes, and all four combinations are possible: futex, robust-futex,
PI-futex, robust+PI-futex.

  glibc support:
  --------------

Ulrich Drepper and Jakub Jelinek have written glibc support for PI-futexes
(and robust futexes), enabling robust and PI (PTHREAD_PRIO_INHERIT) POSIX
mutexes.  (PTHREAD_PRIO_PROTECT support will be added later on too, no
additional kernel changes are needed for that).  [NOTE: The glibc patch is
obviously inofficial and unsupported without matching upstream kernel
functionality.]

the patch-queue and the glibc patch can also be downloaded from:

  http://redhat.com/~mingo/PI-futex-patches/

Many thanks go to the people who helped us create this kernel feature: Steven
Rostedt, Esben Nielsen, Benedikt Spranger, Daniel Walker, John Cooper, Arjan
van de Ven, Oleg Nesterov and others.  Credits for related prior projects goes
to Dirk Grambow, Inaky Perez-Gonzalez, Bill Huey and many others.

Clean up the futex code, before adding more features to it:

 - use u32 as the futex field type - that's the ABI
 - use __user and pointers to u32 instead of unsigned long
 - code style / comment style cleanups
 - rename hash-bucket name from 'bh' to 'hb'.

I checked the pre and post futex.o object files to make sure this
patch has no code effects.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 17:32:46 -07:00