docs, cgroup: add entries for pids to cgroup-v2.rst

This patch add two entries (pids.peak and pids.events) for pids
controller, and also update pids.current because it's on non-root.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 23c600f0db320dc77c4af39c320d1080f84c7412..e73e373297a0c028b7a561eb2a1c52945c128d2c 100644 (file)
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -2184,11 +2184,25 @@ PID Interface Files
        Hard limit of number of processes.
 
   pids.current
-       A read-only single value file which exists on all cgroups.
+       A read-only single value file which exists on non-root cgroups.
 
        The number of processes currently in the cgroup and its
        descendants.
 
+  pids.peak
+       A read-only single value file which exists on non-root cgroups.
+
+       The maximum value that the number of processes in the cgroup and its
+       descendants has ever reached.
+
+  pids.events
+       A read-only flat-keyed file which exists on non-root cgroups. The
+       following entries are defined. Unless specified otherwise, a value
+       change in this file generates a file modified event.
+
+         max
+               Number of times fork failed because limit was hit.
+
 Organisational operations are not blocked by cgroup policies, so it is
 possible to have pids.current > pids.max.  This can be done by either
 setting the limit to be smaller than pids.current, or attaching enough