From c2f31b79d510ec1a27138bdcf2d0ece1080be85e Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 5 Dec 2017 09:10:17 -0800 Subject: 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 Reported-by: "Michael Kerrisk (man-pages)" --- Documentation/cgroup-v2.txt | 7 +++++++ 1 file changed, 7 insertions(+) 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 ~~~~~~~~~~~~~~~~~~~ -- cgit v1.2.3