From: Jeff Layton <jlayton@poochiereds.net>
Date: Tue, 8 Sep 2015 22:03:44 +0000 (-0700)
Subject: list_lru: don't call list_lru_from_kmem if the list_head is empty
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=26f5d7609f03ad8d6dc552458e4e371a62416b37;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

list_lru: don't call list_lru_from_kmem if the list_head is empty

If the list_head is empty then we'll have called list_lru_from_kmem for
nothing.  Move that call inside of the list_empty if block.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 909eca2c820e..e1da19fac1b3 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -99,8 +99,8 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item)
 	struct list_lru_one *l;
 
 	spin_lock(&nlru->lock);
-	l = list_lru_from_kmem(nlru, item);
 	if (list_empty(item)) {
+		l = list_lru_from_kmem(nlru, item);
 		list_add_tail(item, &l->list);
 		l->nr_items++;
 		spin_unlock(&nlru->lock);
@@ -118,8 +118,8 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item)
 	struct list_lru_one *l;
 
 	spin_lock(&nlru->lock);
-	l = list_lru_from_kmem(nlru, item);
 	if (!list_empty(item)) {
+		l = list_lru_from_kmem(nlru, item);
 		list_del_init(item);
 		l->nr_items--;
 		spin_unlock(&nlru->lock);