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yaml --- r: 335788 b: refs/heads/master c: 9a5a8f1 h: refs/heads/master v: v3
git-mirror · Nov 16, 2012 · 0970bc7 · 0970bc7
1 parent 73e941f
commit 0970bc7
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Showing 3 changed files with 20 additions and 7 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1756954c61cb5c97c618ccb366482b9c1f891d6d
+refs/heads/master: 9a5a8f19b43430752067ecaee62fc59e11e88fa6
diff --git a/trunk/Documentation/cgroups/memory.txt b/trunk/Documentation/cgroups/memory.txt
@@ -466,6 +466,10 @@ Note:
 5.3 swappiness
 
 Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only.
+Please note that unlike the global swappiness, memcg knob set to 0
+really prevents from any swapping even if there is a swap storage
+available. This might lead to memcg OOM killer if there are no file
+pages to reclaim.
 
 Following cgroups' swappiness can't be changed.
 - root cgroup (uses /proc/sys/vm/swappiness).

diff --git a/trunk/mm/memcontrol.c b/trunk/mm/memcontrol.c
@@ -1452,17 +1452,26 @@ static int mem_cgroup_count_children(struct mem_cgroup *memcg)
 static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
 {
 	u64 limit;
-	u64 memsw;
 
 	limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
-	limit += total_swap_pages << PAGE_SHIFT;
 
-	memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
 	/*
-	 * If memsw is finite and limits the amount of swap space available
-	 * to this memcg, return that limit.
+	 * Do not consider swap space if we cannot swap due to swappiness
 	 */
-	return min(limit, memsw);
+	if (mem_cgroup_swappiness(memcg)) {
+		u64 memsw;
+
+		limit += total_swap_pages << PAGE_SHIFT;
+		memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
+
+		/*
+		 * If memsw is finite and limits the amount of swap space
+		 * available to this memcg, return that limit.
+		 */
+		limit = min(limit, memsw);
+	}
+
+	return limit;
 }
 
 void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,