Commit c714a534 authored May 12, 2008 by Linus Torvalds

Make 'cond_resched()' nullification depend on PREEMPT_BKL



Because it's not correct with a non-preemptable BKL and just causes
PREEMPT kernels to have longer latencies than non-PREEMPT ones (which is
obviously not the point of it at all).

Of course, that config option actually got removed as an option earlier,
so for now this basically disables it entirely, but if BKL preemption is
ever resurrected it will be a meaningful optimization.  And in the
meantime, it at least documents the intent of the code, while not doing
the wrong thing.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 542dafad

include/linux/sched.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -2038,7 +2038,7 @@ static inline int need_resched(void)
		* cond_resched_softirq() will enable bhs before scheduling.
		*/
		extern int _cond_resched(void);
		#ifdef CONFIG_PREEMPT
		#ifdef CONFIG_PREEMPT_BKL
		static inline int cond_resched(void)
		{
		return 0;