diff options
| 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 | |
| parent | bf89a304722f6904009499a31dc68ab9a5c9742e (diff) | |
| download | linux-9af6528ee9b682df7f29dbee86fbba0b67eab944.tar.bz2 | |
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')
| -rw-r--r-- | include/linux/kernel.h | 9 | ||||
| -rw-r--r-- | include/linux/sched.h | 2 |
2 files changed, 5 insertions, 6 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d96a6118d26a..74fd6f05bc5b 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -259,17 +259,14 @@ static inline void might_fault(void) { } extern struct atomic_notifier_head panic_notifier_list; extern long (*panic_blink)(int state); __printf(1, 2) -void panic(const char *fmt, ...) - __noreturn __cold; +void panic(const char *fmt, ...) __noreturn __cold; void nmi_panic(struct pt_regs *regs, const char *msg); extern void oops_enter(void); extern void oops_exit(void); void print_oops_end_marker(void); extern int oops_may_print(void); -void do_exit(long error_code) - __noreturn; -void complete_and_exit(struct completion *, long) - __noreturn; +void do_exit(long error_code) __noreturn; +void complete_and_exit(struct completion *, long) __noreturn; /* Internal, do not use. */ int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 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; |