Docs/admin-guide/cgroup-v1: document rdma.peak, rdma.events and rdma.events.local

The v1 RDMA controller documentation only describes rdma.max and
rdma.current, but the controller exposes three more files -- rdma.peak,
rdma.events and rdma.events.local -- which are already documented for
v2. Mirror the v2 wording so the v1 documentation matches the files
actually visible on a v1 mount.

Co-developed-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Guopeng Zhang 2026-07-07 18:21:47 +08:00 committed by Tejun Heo
parent 5aa31cb1df
commit 451a746757

View File

@ -9,6 +9,7 @@ RDMA Controller
1-2. Why RDMA controller needed?
1-3. How is RDMA controller implemented?
2. Usage Examples
3. RDMA Interface Files
1. Overview
===========
@ -115,3 +116,68 @@ Following resources can be accounted by rdma controller.
(d) Delete resource limit::
echo mlx4_0 hca_handle=max hca_object=max > /sys/fs/cgroup/rdma/1/rdma.max
3. RDMA Interface Files
========================
The following interface files are available in each non-root RDMA cgroup.
rdma.max
A read-write file which describes the configured resource limit
for an RDMA/IB device. See the Usage Examples above.
rdma.current
A read-only file which describes the current resource usage.
rdma.peak
A read-only nested-keyed file which 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
and contains the following keys:
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 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 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