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authorMikulas Patocka <mpatocka@redhat.com>2014-04-07 15:37:35 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:35:55 -0700
commiteb9a3c62a0b6064c7f7e5b961ce00c646d21cb78 (patch)
treefecb27f0ba700b13c2b05364159c4230589b0099
parentda1c67a76f7cf2b3404823d24f9f10fa91aa5dc5 (diff)
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mempool: add unlikely and likely hints
Add unlikely and likely hints to the function mempool_free. It lays out the code in such a way that the common path is executed straighforward and saves a cache line. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/mempool.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/mempool.c b/mm/mempool.c
index 659aa42bad16..905434f18c97 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -304,9 +304,9 @@ void mempool_free(void *element, mempool_t *pool)
* ensures that there will be frees which return elements to the
* pool waking up the waiters.
*/
- if (pool->curr_nr < pool->min_nr) {
+ if (unlikely(pool->curr_nr < pool->min_nr)) {
spin_lock_irqsave(&pool->lock, flags);
- if (pool->curr_nr < pool->min_nr) {
+ if (likely(pool->curr_nr < pool->min_nr)) {
add_element(pool, element);
spin_unlock_irqrestore(&pool->lock, flags);
wake_up(&pool->wait);