linux/kernel
Linus Torvalds 5695e51619 io_uring-worker.v3-2021-02-25
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Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block

Pull io_uring thread rewrite from Jens Axboe:
 "This converts the io-wq workers to be forked off the tasks in question
  instead of being kernel threads that assume various bits of the
  original task identity.

  This kills > 400 lines of code from io_uring/io-wq, and it's the worst
  part of the code. We've had several bugs in this area, and the worry
  is always that we could be missing some pieces for file types doing
  unusual things (recent /dev/tty example comes to mind, userfaultfd
  reads installing file descriptors is another fun one... - both of
  which need special handling, and I bet it's not the last weird oddity
  we'll find).

  With these identical workers, we can have full confidence that we're
  never missing anything. That, in itself, is a huge win. Outside of
  that, it's also more efficient since we're not wasting space and code
  on tracking state, or switching between different states.

  I'm sure we're going to find little things to patch up after this
  series, but testing has been pretty thorough, from the usual
  regression suite to production. Any issue that may crop up should be
  manageable.

  There's also a nice series of further reductions we can do on top of
  this, but I wanted to get the meat of it out sooner rather than later.
  The general worry here isn't that it's fundamentally broken. Most of
  the little issues we've found over the last week have been related to
  just changes in how thread startup/exit is done, since that's the main
  difference between using kthreads and these kinds of threads. In fact,
  if all goes according to plan, I want to get this into the 5.10 and
  5.11 stable branches as well.

  That said, the changes outside of io_uring/io-wq are:

   - arch setup, simple one-liner to each arch copy_thread()
     implementation.

   - Removal of net and proc restrictions for io_uring, they are no
     longer needed or useful"

* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
  io-wq: remove now unused IO_WQ_BIT_ERROR
  io_uring: fix SQPOLL thread handling over exec
  io-wq: improve manager/worker handling over exec
  io_uring: ensure SQPOLL startup is triggered before error shutdown
  io-wq: make buffered file write hashed work map per-ctx
  io-wq: fix race around io_worker grabbing
  io-wq: fix races around manager/worker creation and task exit
  io_uring: ensure io-wq context is always destroyed for tasks
  arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
  io_uring: cleanup ->user usage
  io-wq: remove nr_process accounting
  io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
  net: remove cmsg restriction from io_uring based send/recvmsg calls
  Revert "proc: don't allow async path resolution of /proc/self components"
  Revert "proc: don't allow async path resolution of /proc/thread-self components"
  io_uring: move SQPOLL thread io-wq forked worker
  io-wq: make io_wq_fork_thread() available to other users
  io-wq: only remove worker from free_list, if it was there
  io_uring: remove io_identity
  io_uring: remove any grabbing of context
  ...
2021-02-27 08:29:02 -08:00
..
bpf idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
cgroup idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
configs staging: ION: remove some references to CONFIG_ION 2021-01-06 17:39:38 +01:00
debug kgdb: fix to kill breakpoints on initmem after boot 2021-02-26 09:41:05 -08:00
dma Merge branch 'stable/for-linus-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2021-02-26 13:59:32 -08:00
entry entry: Explicitly flush pending rcuog wakeup before last rescheduling point 2021-02-17 14:12:43 +01:00
events kernel: delete repeated words in comments 2021-02-26 09:41:03 -08:00
gcov init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov 2021-02-05 11:03:47 -08:00
irq Driver core / debugfs update for 5.12-rc1 2021-02-24 10:13:55 -08:00
kcsan kcsan: Rewrite kcsan_prandom_u32_max() without prandom_u32_state() 2021-01-04 14:39:07 -08:00
livepatch kallsyms: refactor {,module_}kallsyms_on_each_symbol 2021-02-08 12:22:08 +01:00
locking kernel: delete repeated words in comments 2021-02-26 09:41:03 -08:00
power Merge branches 'powercap' and 'pm-misc' 2021-02-15 18:50:01 +01:00
printk Merge branch 'printk-rework' into for-linus 2021-02-22 13:43:55 +01:00
rcu Scheduler updates for v5.12: 2021-02-21 12:35:04 -08:00
sched kernel: delete repeated words in comments 2021-02-26 09:41:03 -08:00
time These are the latest RCU updates for v5.12: 2021-02-21 12:04:41 -08:00
trace tracing: add error_report_end trace point 2021-02-26 09:41:02 -08:00
.gitignore
acct.c kernel/acct.c: use #elif instead of #end and #elif 2020-12-15 22:46:15 -08:00
async.c treewide: Remove uninitialized_var() usage 2020-07-16 12:35:15 -07:00
audit.c audit: Remove leftover reference to the audit_tasklet 2021-01-15 11:58:10 -05:00
audit.h audit: change unnecessary globals into statics 2020-08-17 20:26:58 -04:00
audit_fsnotify.c audit_alloc_mark(): don't open-code ERR_CAST() 2021-02-23 10:25:27 -05:00
audit_tree.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
auditfilter.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
auditsc.c idmapped-mounts-v5.12 2021-02-23 13:39:45 -08:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2020-07-30 11:15:58 -07:00
bounds.c
capability.c capability: handle idmapped mounts 2021-01-24 14:27:16 +01:00
compat.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c
cpu.c cpu/hotplug: Add lockdep_is_cpus_held() 2021-01-06 16:24:59 -08:00
cpu_pm.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
crash_core.c kdump: append uts_namespace.name offset to VMCOREINFO 2020-12-15 22:46:18 -08:00
crash_dump.c
cred.c
delayacct.c
dma.c
exec_domain.c
exit.c kernel/io_uring: cancel io_uring before task works 2020-12-30 19:36:54 -07:00
extable.c
fail_function.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
fork.c Kernel: fork.c: Fix coding style: Do not use {} around single-line statements 2021-01-11 12:55:01 +01:00
freezer.c
futex.c Merge branch 'linus' into locking/core, to pick up upstream fixes 2021-02-12 12:54:58 +01:00
gen_kheaders.sh
groups.c groups: simplify struct group_info allocation 2021-02-26 09:41:03 -08:00
hung_task.c kernel/hung_task.c: make type annotations consistent 2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c irq_work: Optimize irq_work_single() 2020-11-24 16:47:49 +01:00
jump_label.c jump_label: Fix usage in module __init 2020-12-18 16:53:12 +01:00
kallsyms.c kallsyms: only build {,module_}kallsyms_on_each_symbol when required 2021-02-08 12:24:04 +01:00
kcmp.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt preempt: Introduce CONFIG_PREEMPT_DYNAMIC 2021-02-17 14:12:24 +01:00
kcov.c kernel: make kcov_common_handle consider the current context 2020-11-02 18:00:20 -08:00
kexec.c LSM: Introduce kernel_post_load_data() hook 2020-10-05 13:37:03 +02:00
kexec_core.c Merge branch 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-02-21 09:29:23 -08:00
kexec_elf.c
kexec_file.c ima: Free IMA measurement buffer after kexec syscall 2021-02-10 15:49:38 -05:00
kexec_internal.h kexec: move machine_kexec_post_load() to public interface 2021-02-22 12:33:26 +00:00
kheaders.c
kmod.c kmod: remove redundant "be an" in the comment 2020-08-12 10:58:01 -07:00
kprobes.c kprobes: Fix to delay the kprobes jump optimization 2021-02-19 14:57:12 -05:00
ksysfs.c
kthread.c - Correct the marking of kthreads which are supposed to run on a specific, 2021-01-24 10:09:20 -08:00
latencytop.c
Makefile kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE 2021-02-16 09:59:41 +01:00
module-internal.h
module.c module: potential uninitialized return in module_kallsyms_on_each_symbol() 2021-02-10 16:57:04 +01:00
module_signature.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
module_signing.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
notifier.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
nsproxy.c fixes-v5.11 2020-12-14 16:40:27 -08:00
padata.c padata: fix possible padata_works_lock deadlock 2020-09-04 17:51:55 +10:00
panic.c panic: don't dump stack twice on warn 2020-11-14 11:26:04 -08:00
params.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
pid.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
pid_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
profile.c
ptrace.c kernel: treat PF_IO_WORKER like PF_KTHREAD for ptrace/signals 2021-02-21 17:25:22 -07:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c reboot: hide from sysfs not applicable settings 2020-12-15 22:46:19 -08:00
regset.c regset: kill ->get() 2020-07-27 14:31:12 -04:00
relay.c relay: allow the use of const callback structs 2020-12-15 22:46:18 -08:00
resource.c resource: Move devmem revoke code to resource framework 2021-01-12 14:26:31 +01:00
resource_kunit.c resource: provide meaningful MODULE_LICENSE() in test suite 2020-11-25 18:52:35 +01:00
rseq.c
scftorture.c scftorture: Add debug output for wrong-CPU warning 2021-01-04 13:53:41 -08:00
scs.c scs: switch to vmapped shadow stacks 2020-12-01 10:30:28 +00:00
seccomp.c seccomp: Improve performace by optimizing rmb() 2021-02-10 12:40:11 -08:00
signal.c kernel: treat PF_IO_WORKER like PF_KTHREAD for ptrace/signals 2021-02-21 17:25:22 -07:00
smp.c smp: Process pending softirqs in flush_smp_call_function_from_idle() 2021-02-17 14:12:42 +01:00
smpboot.c kthread: Extract KTHREAD_IS_PER_CPU 2021-01-22 15:09:42 +01:00
smpboot.h
softirq.c softirq: Move do_softirq_own_stack() to generic asm header 2021-02-10 23:34:16 +01:00
stackleak.c stackleak: let stack_erasing_sysctl take a kernel pointer buffer 2020-09-19 13:13:39 -07:00
stacktrace.c stacktrace: Remove reliable argument from arch_stack_walk() callback 2020-09-18 14:24:16 +01:00
static_call.c static_call: Allow module use without exposing static_call_key 2021-02-17 14:12:42 +01:00
stop_machine.c Merge branch 'linus' into sched/core, to resolve semantic conflict 2020-11-27 11:10:50 +01:00
sys.c Kbuild updates for v5.12 2021-02-25 10:17:31 -08:00
sys_ni.c epoll: wire up syscall epoll_pwait2 2020-12-19 11:18:38 -08:00
sysctl-test.c
sysctl.c sysctl.c: fix underflow value setting risk in vm_table 2021-02-26 09:41:03 -08:00
task_work.c task_work: remove legacy TWA_SIGNAL path 2020-12-12 09:17:38 -07:00
taskstats.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
test_kprobes.c
torture.c torture: Maintain torture-specific set of CPUs-online books 2021-01-06 17:17:22 -08:00
tracepoint.c tracepoints: Code clean up 2021-02-09 12:27:29 -05:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c usermodehelper: reset umask to default before executing user process 2020-10-06 10:31:52 -07:00
up.c
user-return-notifier.c
user.c user: Use generic ns_common::count 2020-08-19 14:14:12 +02:00
user_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
usermode_driver.c
utsname.c uts: Use generic ns_common::count 2020-08-19 14:13:20 +02:00
utsname_sysctl.c
watch_queue.c watch_queue: rectify kernel-doc for init_watch() 2021-01-26 11:16:34 +00:00
watchdog.c kernel/watchdog: fix watchdog_allowed_mask not used warning 2020-11-14 11:26:03 -08:00
watchdog_hld.c
workqueue.c Merge branch 'for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2021-02-22 17:06:54 -08:00
workqueue_internal.h