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| author | Ingo Molnar <mingo@elte.hu> | 2007-10-15 17:00:13 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-10-15 17:00:13 +0200 |
| commit | 1e819950660e6a811b549422ffb652273257e45e (patch) | |
| tree | 86bd6a49002d97de371c7e89a184a8b44c02b8d7 | |
| parent | sched: fix __pick_next_entity() (diff) | |
| download | linux-1e819950660e6a811b549422ffb652273257e45e.tar.xz linux-1e819950660e6a811b549422ffb652273257e45e.zip | |
sched: optimize schedule() a bit on SMP
optimize schedule() a bit on SMP, by moving the rq-clock update
outside the rq lock.
code size is the same:
text data bss dec hex filename
25725 2666 96 28487 6f47 sched.o.before
25725 2666 96 28487 6f47 sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | kernel/sched.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index e717047be5cf..4f13d379bea5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3481,9 +3481,13 @@ need_resched_nonpreemptible: schedule_debug(prev); - spin_lock_irq(&rq->lock); - clear_tsk_need_resched(prev); + /* + * Do the rq-clock update outside the rq lock: + */ + local_irq_disable(); __update_rq_clock(rq); + spin_lock(&rq->lock); + clear_tsk_need_resched(prev); if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { if (unlikely((prev->state & TASK_INTERRUPTIBLE) && |