From c88914379da35c46d093f6d410b9507355aacd0a Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Thu, 10 Jun 2021 07:13:04 +0200 Subject: [PATCH] MINOR: pools: do not maintain the lock during pool_flush() The locked version of pool_flush() is absurd, it locks the pool for each and every element to be released till the end. Not only this is extremely inefficient, but it may even never finish if other threads spend their time refilling the pool. The only case where this can happen is during soft-stop so the risk remains limited, but it should be addressed. --- src/pool.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/src/pool.c b/src/pool.c index d788c6168..c69143a08 100644 --- a/src/pool.c +++ b/src/pool.c @@ -360,20 +360,19 @@ void pool_gc(struct pool_head *pool_ctx) */ void pool_flush(struct pool_head *pool) { - void *temp; + void *temp, **next; if (!pool) return; - while (1) { - HA_SPIN_LOCK(POOL_LOCK, &pool->lock); - temp = pool->free_list; - if (!temp) { - HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock); - break; - } - pool->free_list = *POOL_LINK(pool, temp); - HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock); + HA_SPIN_LOCK(POOL_LOCK, &pool->lock); + next = pool->free_list; + pool->free_list = NULL; + HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock); + + while (next) { + temp = next; + next = *POOL_LINK(pool, temp); pool_put_to_os(pool, temp); } /* here, we should have pool->allocated == pool->used */