diff options
Diffstat (limited to 'Documentation/admin-guide/cgroup-v2.rst')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 23 |
1 files changed, 10 insertions, 13 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index b8c0460730f3..ce3e05e41724 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -714,9 +714,7 @@ Conventions - Settings for a single feature should be contained in a single file. - The root cgroup should be exempt from resource control and thus - shouldn't have resource control interface files. Also, - informational files on the root cgroup which end up showing global - information available elsewhere shouldn't exist. + shouldn't have resource control interface files. - The default time unit is microseconds. If a different unit is ever used, an explicit unit suffix must be present. @@ -985,7 +983,7 @@ CPU Interface Files All time durations are in microseconds. cpu.stat - A read-only flat-keyed file which exists on non-root cgroups. + A read-only flat-keyed file. This file exists whether the controller is enabled or not. It always reports the following three stats: @@ -1172,6 +1170,13 @@ PAGE_SIZE multiple when read back. Under certain circumstances, the usage may go over the limit temporarily. + In default configuration regular 0-order allocations always + succeed unless OOM killer chooses current task as a victim. + + Some kinds of allocations don't invoke the OOM killer. + Caller could retry them differently, return into userspace + as -ENOMEM or silently ignore in cases like disk readahead. + This is the ultimate protection mechanism. As long as the high limit is used and monitored properly, this limit's utility is limited to providing the final safety net. @@ -1228,17 +1233,9 @@ PAGE_SIZE multiple when read back. The number of time the cgroup's memory usage was reached the limit and allocation was about to fail. - Depending on context result could be invocation of OOM - killer and retrying allocation or failing allocation. - - Failed allocation in its turn could be returned into - userspace as -ENOMEM or silently ignored in cases like - disk readahead. For now OOM in memory cgroup kills - tasks iff shortage has happened inside page fault. - This event is not raised if the OOM killer is not considered as an option, e.g. for failed high-order - allocations. + allocations or if caller asked to not retry attempts. oom_kill The number of processes belonging to this cgroup |