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>
diff --git a/mm/mempool.c b/mm/mempool.c
index 659aa42..905434f 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -304,9 +304,9 @@
* 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);