sched/psi: Per-cgroup PSI accounting disable/re-enable interface

[linux-2.6-microblaze.git] / Documentation / admin-guide / cgroup-v2.rst

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 971c418..4cad4e2 100644 (file)
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -976,6 +976,23 @@ All cgroup core files are prefixed with "cgroup."
        killing cgroups is a process directed operation, i.e. it affects
        the whole thread-group.
 
+  cgroup.pressure
+       A read-write single value file that allowed values are "0" and "1".
+       The default is "1".
+
+       Writing "0" to the file will disable the cgroup PSI accounting.
+       Writing "1" to the file will re-enable the cgroup PSI accounting.
+
+       This control attribute is not hierarchical, so disable or enable PSI
+       accounting in a cgroup does not affect PSI accounting in descendants
+       and doesn't need pass enablement via ancestors from root.
+
+       The reason this control attribute exists is that PSI accounts stalls for
+       each cgroup separately and aggregates it at each level of the hierarchy.
+       This may cause non-negligible overhead for some workloads when under
+       deep level of the hierarchy, in which case this control attribute can
+       be used to disable PSI accounting in the non-leaf cgroups.
+
   irq.pressure
        A read-write nested-keyed file.