Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

[linux-2.6-omap-h63xx.git] / Documentation / cgroups / memcg_test.txt

diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt
index a9263596f8d8e425289aa6525484d72fea024a54..72db89ed0609c8582d24e0fa54f72c10f4c8af96 100644 (file)
--- a/Documentation/cgroups/memcg_test.txt
+++ b/Documentation/cgroups/memcg_test.txt
@@ -1,5 +1,5 @@
 Memory Resource Controller(Memcg)  Implementation Memo.
-Last Updated: 2009/1/19
+Last Updated: 2009/1/20
 Base Kernel Version: based on 2.6.29-rc2.
 
 Because VM is getting complex (one of reasons is memcg...), memcg's behavior
@@ -360,3 +360,21 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
        # kill malloc task.
 
        Of course, tmpfs v.s. swapoff test should be tested, too.
+
+ 9.8 OOM-Killer
+       Out-of-memory caused by memcg's limit will kill tasks under
+       the memcg. When hierarchy is used, a task under hierarchy
+       will be killed by the kernel.
+       In this case, panic_on_oom shouldn't be invoked and tasks
+       in other groups shouldn't be killed.
+
+       It's not difficult to cause OOM under memcg as following.
+       Case A) when you can swapoff
+       #swapoff -a
+       #echo 50M > /memory.limit_in_bytes
+       run 51M of malloc
+
+       Case B) when you use mem+swap limitation.
+       #echo 50M > memory.limit_in_bytes
+       #echo 50M > memory.memsw.limit_in_bytes
+       run 51M of malloc