[PATCH] mm/zbud: init user ops only when it is needed

From: Heesub Shin
Date: Wed Oct 15 2014 - 06:00:53 EST


When zbud is initialized through the zpool wrapper, pool->ops which
points to user-defined operations is always set regardless of whether it
is specified from the upper layer. This causes zbud_reclaim_page() to
iterate its loop for evicting pool pages out without any gain.

This patch sets the user-defined ops only when it is needed, so that
zbud_reclaim_page() can bail out the reclamation loop earlier if there
is no user-defined operations specified.

Signed-off-by: Heesub Shin <heesub.shin@xxxxxxxxxxx>
---
mm/zbud.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/zbud.c b/mm/zbud.c
index ecf1dbe..db8de74 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -132,7 +132,7 @@ static struct zbud_ops zbud_zpool_ops = {

static void *zbud_zpool_create(gfp_t gfp, struct zpool_ops *zpool_ops)
{
- return zbud_create_pool(gfp, &zbud_zpool_ops);
+ return zbud_create_pool(gfp, zpool_ops ? &zbud_zpool_ops : NULL);
}

static void zbud_zpool_destroy(void *pool)
--
1.9.1

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