diff options
Diffstat (limited to 'Documentation/cgroup-v2.txt')
-rw-r--r-- | Documentation/cgroup-v2.txt | 49 |
1 files changed, 24 insertions, 25 deletions
diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt index dc44785dc0fa..2cddab7efb20 100644 --- a/Documentation/cgroup-v2.txt +++ b/Documentation/cgroup-v2.txt @@ -893,15 +893,18 @@ Controllers CPU --- -.. note:: - - The interface for the cpu controller hasn't been merged yet - The "cpu" controllers regulates distribution of CPU cycles. This 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 ~~~~~~~~~~~~~~~~~~~ @@ -910,12 +913,16 @@ All time durations are in microseconds. cpu.stat A read-only flat-keyed file which exists on non-root cgroups. + This file exists whether the controller is enabled or not. - It reports the following six stats: + It always reports the following three stats: - usage_usec - user_usec - system_usec + + and the following three when the controller is enabled: + - nr_periods - nr_throttled - throttled_usec @@ -926,6 +933,18 @@ All time durations are in microseconds. The weight in the range [1, 10000]. + cpu.weight.nice + A read-write single value file which exists on non-root + cgroups. The default is "0". + + The nice value is in the range [-20, 19]. + + This interface file is an alternative interface for + "cpu.weight" and allows reading and setting weight using the + same values used by nice(2). Because the range is smaller and + granularity is coarser for the nice values, the read value is + the closest approximation of the current weight. + cpu.max A read-write two value file which exists on non-root cgroups. The default is "max 100000". @@ -938,26 +957,6 @@ All time durations are in microseconds. $PERIOD duration. "max" for $MAX indicates no limit. If only one number is written, $MAX is updated. - cpu.rt.max - .. note:: - - The semantics of this file is still under discussion and the - interface hasn't been merged yet - - A read-write two value file which exists on all cgroups. - The default is "0 100000". - - The maximum realtime runtime allocation. Over-committing - configurations are disallowed and process migrations are - rejected if not enough bandwidth is available. It's in the - following format:: - - $MAX $PERIOD - - which indicates that the group may consume upto $MAX in each - $PERIOD duration. If only one number is written, $MAX is - updated. - Memory ------ |