cgroup: add cgroup.stat interface with basic hierarchy stats

[sfrench/cifs-2.6.git] / Documentation / cgroup-v2.txt

diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt
index 46ec3f76211c60f1a690b7927688825258f9f858..dc44785dc0fa146a2de30aa11ef2c410f1b00622 100644 (file)
--- a/Documentation/cgroup-v2.txt
+++ b/Documentation/cgroup-v2.txt
@@ -868,6 +868,24 @@ All cgroup core files are prefixed with "cgroup."
        If the actual descent depth is equal or larger,
        an attempt to create a new child cgroup will fail.
 
+  cgroup.stat
+       A read-only flat-keyed file with the following entries:
+
+         nr_descendants
+               Total number of visible descendant cgroups.
+
+         nr_dying_descendants
+               Total number of dying descendant cgroups. A cgroup becomes
+               dying after being deleted by a user. The cgroup will remain
+               in dying state for some time undefined time (which can depend
+               on system load) before being completely destroyed.
+
+               A process can't enter a dying cgroup under any circumstances,
+               a dying cgroup can't revive.
+
+               A dying cgroup can consume system resources not exceeding
+               limits, which were active at the moment of cgroup deletion.
+
 
 Controllers
 ===========