From eb9a3c62a0b6064c7f7e5b961ce00c646d21cb78 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 7 Apr 2014 15:37:35 -0700 Subject: [PATCH] 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 Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempool.c | 4 ++-- 1 file 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); -- 2.20.1