lib/percpu_counter.c: __this_cpu_write() doesn't need to be protected by spinlock

__this_cpu_write doesn't need to be protected by spinlock, AS we are doing
per cpu write with preempt disabled.  And another reason to remove
__this_cpu_write outside of spinlock: __percpu_counter_sum is not an
accurate counter.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Fan Du 2013-07-03 15:05:19 -07:00 committed by Linus Torvalds
parent 5cb0656b62
commit 64df3071a9

View File

@ -80,8 +80,8 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
if (count >= batch || count <= -batch) {
raw_spin_lock(&fbc->lock);
fbc->count += count;
__this_cpu_write(*fbc->counters, 0);
raw_spin_unlock(&fbc->lock);
__this_cpu_write(*fbc->counters, 0);
} else {
__this_cpu_write(*fbc->counters, count);
}