[PATCH v2] mm/list_lru: optimize condition of exiting the loop

[Hui Su <sh_def@163.com>]

In list_lru_walk(), nr_to_walk type is 'unsigned long',
so nr_to_walk won't be '< 0'.

In list_lru_walk_node(), nr_to_walk type is 'unsigned long',
so *nr_to_walk won't be '< 0' too.

We can use '!nr_to_walk' instead of 'nr_to_walk <= 0', which
is more precise.

Signed-off-by: Hui Su <sh_def@163.com>
---
 include/linux/list_lru.h | 2 +-
 mm/list_lru.c            | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 9dcaa3e582c9..b7bc4a2636b9 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -214,7 +214,7 @@ list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate,
 	for_each_node_state(nid, N_NORMAL_MEMORY) {
 		isolated += list_lru_walk_node(lru, nid, isolate,
 					       cb_arg, &nr_to_walk);
-		if (nr_to_walk <= 0)
+		if (!nr_to_walk)
 			break;
 	}
 	return isolated;
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 5aa6e44bc2ae..35be4de9fd77 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -294,7 +294,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
 
 	isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
 				      nr_to_walk);
-	if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
+	if (*nr_to_walk && list_lru_memcg_aware(lru)) {
 		for_each_memcg_cache_index(memcg_idx) {
 			struct list_lru_node *nlru = &lru->node[nid];
 
@@ -304,7 +304,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
 							nr_to_walk);
 			spin_unlock(&nlru->lock);
 
-			if (*nr_to_walk <= 0)
+			if (!*nr_to_walk)
 				break;
 		}
 	}
-- 
2.29.0