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authorTejun Heo <tj@kernel.org>2017-12-05 18:10:17 +0100
committerTejun Heo <tj@kernel.org>2017-12-05 20:47:17 +0100
commitc2f31b79d510ec1a27138bdcf2d0ece1080be85e (patch)
tree96101d852e918b16cda3973da65de900e1943b5b
parentRevert "cgroup/cpuset: remove circular dependency deadlock" (diff)
downloadlinux-c2f31b79d510ec1a27138bdcf2d0ece1080be85e.tar.xz
linux-c2f31b79d510ec1a27138bdcf2d0ece1080be85e.zip
cgroup: add warning about RT not being supported on cgroup2
We haven't yet figured out what to do with RT threads on cgroup2. Document the limitation. v2: Included the warning about system management software behavior as suggested by Michael. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
-rw-r--r--Documentation/cgroup-v2.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt
index 779211fbb69f..2cddab7efb20 100644
--- a/Documentation/cgroup-v2.txt
+++ b/Documentation/cgroup-v2.txt
@@ -898,6 +898,13 @@ controller implements weight and absolute bandwidth limit models for
normal scheduling policy and absolute bandwidth allocation model for
realtime scheduling policy.
+WARNING: cgroup2 doesn't yet support control of realtime processes and
+the cpu controller can only be enabled when all RT processes are in
+the root cgroup. Be aware that system management software may already
+have placed RT processes into nonroot cgroups during the system boot
+process, and these processes may need to be moved to the root cgroup
+before the cpu controller can be enabled.
+
CPU Interface Files
~~~~~~~~~~~~~~~~~~~