Peter Zijlstra bebe5b5143 futex: Futex_unlock_pi() determinism ...

The problem with returning -EAGAIN when the waiter state mismatches is that
it becomes very hard to proof a bounded execution time on the
operation. And seeing that this is a RT operation, this is somewhat
important.

While in practise; given the previous patch; it will be very unlikely to
ever really take more than one or two rounds, proving so becomes rather
hard.

However, now that modifying wait_list is done while holding both hb->lock
and wait_lock, the scenario can be avoided entirely by acquiring wait_lock
while still holding hb-lock. Doing a hand-over, without leaving a hole.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: juri.lelli@arm.com
Cc: bigeasy@linutronix.de
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: jdesfossez@efficios.com
Cc: dvhart@infradead.org
Cc: bristot@redhat.com
Link: http://lkml.kernel.org/r/20170322104152.112378812@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2017-03-23 19:10:10 +01:00

..

bpf

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-03-04 17:31:39 -08:00

cgroup

scripts/spelling.txt: add "disble(d)" pattern and fix typo instances

2017-03-09 17:01:09 -08:00

configs

config: android-base: enable hardened usercopy and kernel ASLR

2017-02-27 18:43:46 -08:00

debug

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>

2017-03-02 08:42:34 +01:00

events

scripts/spelling.txt: add "disble(d)" pattern and fix typo instances

2017-03-09 17:01:09 -08:00

gcov

gcov: add support for gcc version >= 6

2016-07-15 14:54:27 +09:00

irq

sched/headers: Prepare to move the get_task_struct()/put_task_struct() and related APIs from <linux/sched.h> to <linux/sched/task.h>

2017-03-02 08:42:40 +01:00

livepatch

livepatch/module: make TAINT_LIVEPATCH module-specific

2016-08-26 14:42:08 +02:00

locking

futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()

2017-03-23 19:10:09 +01:00

power

Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-03-03 10:16:38 -08:00

printk

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>

2017-03-02 08:42:36 +01:00

rcu

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>

2017-03-02 08:42:34 +01:00

sched

Merge tag 'pm-4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2017-03-09 16:30:37 -08:00

time

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-03-07 14:45:22 -08:00

trace

scripts/spelling.txt: add "overide" pattern and fix typo instances

2017-03-09 17:01:09 -08:00

.gitignore

…

acct.c

sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>

2017-03-02 08:42:39 +01:00

async.c

…

audit_fsnotify.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-12-17 18:44:00 -08:00

audit_tree.c

Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit

2017-01-05 23:06:06 -08:00

audit_watch.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-12-17 18:44:00 -08:00

audit.c

Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit

2017-02-21 13:25:50 -08:00

audit.h

Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit

2017-02-21 13:25:50 -08:00

auditfilter.c

audit: add support for session ID user filter

2016-11-29 15:10:12 -05:00

auditsc.c

Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit

2017-02-21 13:25:50 -08:00

backtracetest.c

…

bounds.c

…

capability.c

capability: export has_capability

2017-01-12 07:01:56 -07:00

compat.c

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

2016-12-24 11:46:01 -08:00

configs.c

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

2016-12-24 11:46:01 -08:00

context_tracking.c

…

cpu_pm.c

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cpu.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>

2017-03-02 08:42:35 +01:00

crash_dump.c

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cred.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h>

2017-03-02 08:42:28 +01:00

delayacct.c

sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>

2017-03-02 08:42:39 +01:00

dma.c

…

elfcore.c

…

exec_domain.c

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exit.c

userfaultfd: non-cooperative: rollback userfaultfd_exit

2017-03-09 17:01:09 -08:00

extable.c

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2017-02-22 10:15:09 -08:00

fork.c

sched/headers, RCU: Move rcu_copy_process() from <linux/sched/task.h> to kernel/fork.c

2017-03-03 01:43:46 +01:00

freezer.c

freezer, oom: check TIF_MEMDIE on the correct task

2016-07-28 16:07:41 -07:00

futex_compat.c

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

2016-12-24 11:46:01 -08:00

futex.c

futex: Futex_unlock_pi() determinism

2017-03-23 19:10:10 +01:00

groups.c

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

2016-12-24 11:46:01 -08:00

hung_task.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>

2017-03-02 08:42:34 +01:00

irq_work.c

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jump_label.c

Merge tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2017-02-27 13:26:17 -08:00

kallsyms.c

bpf: make jited programs visible in traces

2017-02-17 13:40:05 -05:00

kcmp.c

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Kconfig.freezer

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Kconfig.hz

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Kconfig.locks

locking/mutex: Allow MUTEX_SPIN_ON_OWNER when DEBUG_MUTEXES

2016-10-25 11:31:51 +02:00

Kconfig.preempt

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kcov.c

kcov: make kcov work properly with KASLR enabled

2016-12-20 09:48:47 -08:00

kexec_core.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2017-02-22 17:33:34 -08:00

kexec_file.c

kexec, x86/purgatory: Unbreak it and clean it up

2017-03-10 20:55:09 +01:00

kexec_internal.h

kexec, x86/purgatory: Unbreak it and clean it up

2017-03-10 20:55:09 +01:00

kexec.c

kexec: allow architectures to override boot mapping

2016-08-02 19:35:27 -04:00

kmod.c

sched/headers, vfs/execve: Prepare to move the do_execve*() prototypes from <linux/sched.h> to <linux/binfmts.h>

2017-03-02 08:42:39 +01:00

kprobes.c

Merge tag 'powerpc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2017-02-22 10:30:38 -08:00

ksysfs.c

kernel/ksysfs.c: add __ro_after_init to bin_attribute structure

2017-02-24 17:46:56 -08:00

kthread.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>

2017-03-02 08:42:35 +01:00

latencytop.c

sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>

2017-03-02 08:42:39 +01:00

Makefile

cgroup: move cgroup files under kernel/cgroup/

2016-12-27 14:49:05 -05:00

membarrier.c

Fix: Disable sys_membarrier when nohz_full is enabled

2017-01-23 11:32:16 -08:00

memremap.c

mm, devm_memremap_pages: hold device_hotplug lock over mem_hotplug_{begin, done}

2017-02-24 17:46:53 -08:00

module_signing.c

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module-internal.h

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module.c

locking/lockdep: Handle statically initialized PER_CPU locks properly

2017-03-16 09:57:08 +01:00

notifier.c

kernel/notifier.c: simplify expression

2017-02-24 17:46:56 -08:00

nsproxy.c

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padata.c

padata: Remove unused but set variables

2016-10-25 11:08:10 +08:00

panic.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>

2017-03-02 08:42:34 +01:00

params.c

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pid_namespace.c

sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency

2017-03-02 08:42:37 +01:00

pid.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>

2017-03-02 08:42:35 +01:00

profile.c

sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() from <linux/sched.h> to <linux/sched/stat.h>

2017-03-02 08:42:39 +01:00

ptrace.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>

2017-03-02 08:42:35 +01:00

range.c

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reboot.c

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relay.c

lib/vsprintf.c: remove %Z support

2017-02-27 18:43:47 -08:00

resource.c

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seccomp.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>

2017-03-02 08:42:36 +01:00

signal.c

sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>

2017-03-02 08:42:39 +01:00

smp.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/idle.h>

2017-03-02 08:42:26 +01:00

smpboot.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>

2017-03-02 08:42:35 +01:00

smpboot.h

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softirq.c

softirq: Display IRQ_POLL for irq-poll statistics

2016-10-21 15:45:47 -06:00

stacktrace.c

stacktrace, lockdep: Fix address, newline ugliness

2017-02-08 08:21:31 +01:00

stop_machine.c

locking/core, stop_machine: Yield the CPU during stop machine()

2016-11-16 10:15:09 +01:00

sys_ni.c

move aio compat to fs/aio.c

2016-12-22 22:58:37 -05:00

sys.c

sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>

2017-03-02 08:42:39 +01:00

sysctl_binary.c

sysctl: add KERN_CONT to deprecated_sysctl_warning()

2016-12-14 16:04:07 -08:00

sysctl.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/coredump.h>

2017-03-02 08:42:28 +01:00

task_work.c

task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works

2016-08-02 19:35:02 -04:00

taskstats.c

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2016-11-15 10:54:36 -05:00

test_kprobes.c

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torture.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>

2017-03-02 08:42:27 +01:00

tracepoint.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>

2017-03-02 08:42:35 +01:00

tsacct.c

sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>

2017-03-02 08:42:39 +01:00

ucount.c

ucount: Remove the atomicity from ucount->count

2017-03-06 15:26:37 -06:00

uid16.c

sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>

2017-03-02 08:42:31 +01:00

up.c

smp: Add function to execute a function synchronously on a CPU

2016-09-05 13:52:39 +02:00

user_namespace.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h>

2017-03-02 08:42:29 +01:00

user-return-notifier.c

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user.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h>

2017-03-02 08:42:29 +01:00

utsname_sysctl.c

sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>

2017-03-03 01:45:36 +01:00

utsname.c

sched/headers: Prepare to move the task_lock()/unlock() APIs to <linux/sched/task.h>

2017-03-02 08:42:38 +01:00

watchdog_hld.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>

2017-03-02 08:42:34 +01:00

watchdog.c

sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>

2017-03-02 08:42:34 +01:00

workqueue_internal.h

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workqueue.c

time: Remove CONFIG_TIMER_STATS

2017-02-10 11:15:08 +01:00