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| author | Geliang Tang <geliangtang@163.com> | 2015-11-05 18:48:38 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-05 19:34:48 -0800 |
| commit | c9427bc043da23de03d142c3c87ce4a57297c471 (patch) | |
| tree | 6bf0e3c64dbcbbcf5c3d47bae6521acaf5ff2880 /mm/nommu.c | |
| parent | 1e3ee14b9355a688ffe24725fa746ab120c42881 (diff) | |
| download | lwn-c9427bc043da23de03d142c3c87ce4a57297c471.tar.gz lwn-c9427bc043da23de03d142c3c87ce4a57297c471.zip | |
mm/nommu.c: drop unlikely inside BUG_ON()
(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>
Diffstat (limited to 'mm/nommu.c')
| -rw-r--r-- | mm/nommu.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index 1e0f1688d9a4..92be862c859b 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -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; } |