From d86ee4809d0329d4aa0d0f2c76c2295a16862799 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 10 Jul 2009 14:57:57 +0200 Subject: sched: optimize cond_resched() Optimize cond_resched() by removing one conditional. Currently cond_resched() checks system_state == SYSTEM_RUNNING in order to avoid scheduling before the scheduler is running. We can however, as per suggestion of Matt, use PREEMPT_ACTIVE to accomplish that very same. Suggested-by: Matt Mackall Signed-off-by: Peter Zijlstra Acked-by: Matt Mackall Signed-off-by: Linus Torvalds --- include/linux/sched.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 2a99f1c15cf..16a982e389f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -501,8 +501,11 @@ struct task_cputime { /* * Disable preemption until the scheduler is running. * Reset by start_kernel()->sched_init()->init_idle(). + * + * We include PREEMPT_ACTIVE to avoid cond_resched() from working + * before the scheduler is active -- see should_resched(). */ -#define INIT_PREEMPT_COUNT (1) +#define INIT_PREEMPT_COUNT (1 + PREEMPT_ACTIVE) /** * struct thread_group_cputimer - thread group interval timer counts -- cgit v1.2.3