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mm/nommu.c: drop unlikely inside BUG_ON()

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(1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't
    care less and the change is ok.

(2) ppc and mips, which HAVE_ARCH_BUG_ON, do not rely on branch
    predictions as it seems to be pointless[1] and thus callers should not
    be trying to push an optimization in the first place.

(3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an
    unlikely compiler flag already.

Hence, we can drop unlikely behind BUG_ON().

[1] http://lkml.iu.edu/hypermail/linux/kernel/1101.3/02289.html

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Geliang Tang 2015-11-05 18:48:38 -08:00 committed by Linus Torvalds
parent 1e3ee14b93
commit c9427bc043
1 changed files with 5 additions and 5 deletions
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10
mm/nommu.c
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@ -578,16 +578,16 @@ static noinline void validate_nommu_regions(void)
return;
last = rb_entry(lastp, struct vm_region, vm_rb);
BUG_ON(unlikely(last->vm_end <= last->vm_start));
BUG_ON(unlikely(last->vm_top < last->vm_end));
BUG_ON(last->vm_end <= last->vm_start);
BUG_ON(last->vm_top < last->vm_end);
while ((p = rb_next(lastp))) {
region = rb_entry(p, struct vm_region, vm_rb);
last = rb_entry(lastp, struct vm_region, vm_rb);
BUG_ON(unlikely(region->vm_end <= region->vm_start));
BUG_ON(unlikely(region->vm_top < region->vm_end));
BUG_ON(unlikely(region->vm_start < last->vm_top));
BUG_ON(region->vm_end <= region->vm_start);
BUG_ON(region->vm_top < region->vm_end);
BUG_ON(region->vm_start < last->vm_top);
lastp = p;
}