cgroup/rdma: document rdma.peak, rdma.events and rdma.events.local

Add interface file documentation for the new rdma cgroup files to
Documentation/admin-guide/cgroup-v2.rst.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
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 6efd0095ed995b1550317662bc1b56c7a7f3db23..993446ab66d0fbc4f801d8e0bd47ab720af50618 100644 (file)
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -2785,6 +2785,59 @@ RDMA Interface Files
          mlx4_0 hca_handle=1 hca_object=20
          ocrdma1 hca_handle=1 hca_object=23
 
+  rdma.peak
+       A read-only nested-keyed file that exists for all the cgroups
+       except root.  It shows the historical high watermark of
+       resource usage per device since the cgroup was created.
+
+       An example for mlx4 and ocrdma device follows::
+
+         mlx4_0 hca_handle=1 hca_object=20
+         ocrdma1 hca_handle=0 hca_object=23
+
+  rdma.events
+       A read-only nested-keyed file which exists on non-root
+       cgroups.  The following nested keys are defined.
+
+         max
+               The number of times a process in this cgroup or its
+               descendants attempted an RDMA resource allocation that
+               was rejected because a rdma.max limit in the subtree
+               was reached.  This is a hierarchical counter: the event
+               is propagated upward to all ancestor cgroups.  A value
+               change in this file generates a file modified event.
+
+         alloc_fail
+               The number of RDMA resource allocation attempts that
+               originated in this cgroup or its descendants and failed
+               due to a rdma.max limit being reached.  This is a
+               hierarchical counter propagated upward.
+
+       An example for mlx4 device follows::
+
+         mlx4_0 hca_handle.max=5 hca_handle.alloc_fail=3 hca_object.max=0 hca_object.alloc_fail=0
+
+  rdma.events.local
+       Similar to rdma.events but the fields in the file are local
+       to the cgroup i.e. not hierarchical.  The file modified event
+       generated on this file reflects only the local events.
+
+       The following nested keys are defined.
+
+         max
+               The number of times a process in this cgroup or its
+               descendants attempted an RDMA resource allocation that
+               was rejected because this cgroup's own rdma.max limit
+               was reached.
+         alloc_fail
+               The number of RDMA resource allocation attempts
+               originating from this cgroup that failed due to this
+               cgroup's or an ancestor's rdma.max limit.
+
+       An example for mlx4 device follows::
+
+         mlx4_0 hca_handle.max=5 hca_handle.alloc_fail=0 hca_object.max=0 hca_object.alloc_fail=0
+
 DMEM
 ----