Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

[sfrench/cifs-2.6.git] / Documentation / cgroups / memcg_test.txt

diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt
index 72db89ed0609c8582d24e0fa54f72c10f4c8af96..f7f68b2ac1990058b03f078019083d9865b36773 100644 (file)
--- a/Documentation/cgroups/memcg_test.txt
+++ b/Documentation/cgroups/memcg_test.txt
@@ -1,6 +1,6 @@
 Memory Resource Controller(Memcg)  Implementation Memo.
-Last Updated: 2009/1/20
-Base Kernel Version: based on 2.6.29-rc2.
+Last Updated: 2010/2
+Base Kernel Version: based on 2.6.33-rc7-mm(candidate for 34).
 
 Because VM is getting complex (one of reasons is memcg...), memcg's behavior
 is complex. This is a document for memcg's internal behavior.
@@ -337,7 +337,7 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
        race and lock dependency with other cgroup subsystems.
 
        example)
-       # mount -t cgroup none /cgroup -t cpuset,memory,cpu,devices
+       # mount -t cgroup none /cgroup -o cpuset,memory,cpu,devices
 
        and do task move, mkdir, rmdir etc...under this.
 
@@ -348,7 +348,7 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
 
        For example, test like following is good.
        (Shell-A)
-       # mount -t cgroup none /cgroup -t memory
+       # mount -t cgroup none /cgroup -o memory
        # mkdir /cgroup/test
        # echo 40M > /cgroup/test/memory.limit_in_bytes
        # echo 0 > /cgroup/test/tasks
@@ -378,3 +378,42 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
        #echo 50M > memory.limit_in_bytes
        #echo 50M > memory.memsw.limit_in_bytes
        run 51M of malloc
+
+ 9.9 Move charges at task migration
+       Charges associated with a task can be moved along with task migration.
+
+       (Shell-A)
+       #mkdir /cgroup/A
+       #echo $$ >/cgroup/A/tasks
+       run some programs which uses some amount of memory in /cgroup/A.
+
+       (Shell-B)
+       #mkdir /cgroup/B
+       #echo 1 >/cgroup/B/memory.move_charge_at_immigrate
+       #echo "pid of the program running in group A" >/cgroup/B/tasks
+
+       You can see charges have been moved by reading *.usage_in_bytes or
+       memory.stat of both A and B.
+       See 8.2 of Documentation/cgroups/memory.txt to see what value should be
+       written to move_charge_at_immigrate.
+
+ 9.10 Memory thresholds
+       Memory controler implements memory thresholds using cgroups notification
+       API. You can use Documentation/cgroups/cgroup_event_listener.c to test
+       it.
+
+       (Shell-A) Create cgroup and run event listener
+       # mkdir /cgroup/A
+       # ./cgroup_event_listener /cgroup/A/memory.usage_in_bytes 5M
+
+       (Shell-B) Add task to cgroup and try to allocate and free memory
+       # echo $$ >/cgroup/A/tasks
+       # a="$(dd if=/dev/zero bs=1M count=10)"
+       # a=
+
+       You will see message from cgroup_event_listener every time you cross
+       the thresholds.
+
+       Use /cgroup/A/memory.memsw.usage_in_bytes to test memsw thresholds.
+
+       It's good idea to test root cgroup as well.