4 files changed, 33 insertions, 6 deletions

diff --git a/Documentation/cgroups/blkio-controller.txt b/Documentation/cgroups/blkio-controller.txt
index d6da611f8f63..4ed7b5ceeed2 100644
--- a/Documentation/cgroups/blkio-controller.txt
+++ b/Documentation/cgroups/blkio-controller.txt
@@ -89,6 +89,33 @@ Throttling/Upper Limit policy
 
  Limits for writes can be put using blkio.write_bps_device file.
 
+Hierarchical Cgroups
+====================
+- Currently none of the IO control policy supports hierarhical groups. But
+  cgroup interface does allow creation of hierarhical cgroups and internally
+  IO policies treat them as flat hierarchy.
+
+  So this patch will allow creation of cgroup hierarhcy but at the backend
+  everything will be treated as flat. So if somebody created a hierarchy like
+  as follows.
+
+                        root
+                        /  \
+                     test1 test2
+                        |
+                     test3
+
+  CFQ and throttling will practically treat all groups at same level.
+
+                                pivot
+                             /  |   \  \
+                        root  test1 test2  test3
+
+  Down the line we can implement hierarchical accounting/control support
+  and also introduce a new cgroup file "use_hierarchy" which will control
+  whether cgroup hierarchy is viewed as flat or hierarchical by the policy..
+  This is how memory controller also has implemented the things.
+
 Various user visible config options
 ===================================
 CONFIG_BLK_CGROUP
diff --git a/Documentation/cgroups/cgroup_event_listener.c b/Documentation/cgroups/cgroup_event_listener.c
index 8c2bfc4a6358..3e082f96dc12 100644
--- a/Documentation/cgroups/cgroup_event_listener.c
+++ b/Documentation/cgroups/cgroup_event_listener.c
@@ -91,7 +91,7 @@ int main(int argc, char **argv)
 
                 if (ret == -1) {
                         perror("cgroup.event_control "
-                                        "is not accessable any more");
+                                        "is not accessible any more");
                         break;
                 }
 
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index 190018b0c649..44b8b7af8019 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -355,13 +355,13 @@ subsystems, type:
 
 To change the set of subsystems bound to a mounted hierarchy, just
 remount with different options:
-# mount -o remount,cpuset,ns hier1 /dev/cgroup
+# mount -o remount,cpuset,blkio hier1 /dev/cgroup
 
-Now memory is removed from the hierarchy and ns is added.
+Now memory is removed from the hierarchy and blkio is added.
 
-Note this will add ns to the hierarchy but won't remove memory or
+Note this will add blkio to the hierarchy but won't remove memory or
 cpuset, because the new options are appended to the old ones:
-# mount -o remount,ns /dev/cgroup
+# mount -o remount,blkio /dev/cgroup
 
 To Specify a hierarchy's release_agent:
 # mount -t cgroup -o cpuset,release_agent="/sbin/cpuset_release_agent" \
diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt
index b7eececfb195..fc8fa97a09ac 100644
--- a/Documentation/cgroups/memcg_test.txt
+++ b/Documentation/cgroups/memcg_test.txt
@@ -398,7 +398,7 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
         written to move_charge_at_immigrate.
 
  9.10 Memory thresholds
-        Memory controler implements memory thresholds using cgroups notification
+        Memory controller implements memory thresholds using cgroups notification
         API. You can use Documentation/cgroups/cgroup_event_listener.c to test
         it.