Commit eb9a3c62 authored Apr 07, 2014 by Mikulas Patocka Committed by Linus Torvalds Apr 07, 2014

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>

parent da1c67a7

mm/mempool.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);