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| author |   Peter Zijlstra <peterz@infradead.org> | 2016-09-13 18:37:29 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-09-22 14:53:45 +0200 |
| commit | 9af6528ee9b682df7f29dbee86fbba0b67eab944 (patch) | |
| tree | 4c4d95d0ab025f7d7120694718670efce57488b2 /include/linux/sched.h | |
| parent | stop_machine: Avoid a sleep and wakeup in stop_one_cpu() (diff) | |
| download | linux-dev-9af6528ee9b682df7f29dbee86fbba0b67eab944.tar.xz linux-dev-9af6528ee9b682df7f29dbee86fbba0b67eab944.zip | |
sched/core: Optimize __schedule()
Oleg noted that by making do_exit() use __schedule() for the TASK_DEAD
context switch, we can avoid the TASK_DEAD special case currently in
__schedule() because that avoids the extra preempt_disable() from
schedule().
In order to facilitate this, create a do_task_dead() helper which we
place in the scheduler code, such that it can access __schedule().
Also add some __noreturn annotations to the functions, there's no
coming back from do_exit().
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Cheng Chao <cs.os.kernel@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: chris@chris-wilson.co.uk
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/20160913163729.GB5012@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index d75024053e9b..f00ee8e90a29 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -448,6 +448,8 @@ static inline void io_schedule(void) io_schedule_timeout(MAX_SCHEDULE_TIMEOUT); } +void __noreturn do_task_dead(void); + struct nsproxy; struct user_namespace; |