Make 'cond_resched()' nullification depend on PREEMPT_BKL
authorLinus Torvalds <torvalds@linux-foundation.org>
Mon, 12 May 2008 20:34:13 +0000 (13:34 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 12 May 2008 20:34:13 +0000 (13:34 -0700)
commitc714a534d85576af21b06be605ca55cb2fb887ee
tree2d0501e6426b9e069082fd6f09da02c2334832e0
parent542dafadd81eb5826280f7714592930144ae3e1f
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>
include/linux/sched.h