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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-16 03:06:08 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-05-16 03:06:08 +0300 |
commit | de6fef50eaf40789b11841474726fd918a3a84a1 (patch) | |
tree | df6e1395240b9275e1f5d064edd6957cf3d8d510 /Documentation/admin-guide/cgroup-v2.rst | |
parent | f4b0c4b508364fde023e4f7b9f23f7e38c663dfe (diff) | |
parent | 21c38a3bd4ee3fb7337d013a638302fb5e5f9dc2 (diff) | |
download | linux-de6fef50eaf40789b11841474726fd918a3a84a1.tar.xz |
Merge tag 'cgroup-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- The locking around cpuset hotplug processing has always been a bit of
mess which was worked around by making hotplug processing
asynchronous. The asynchronity isn't great and led to other issues.
We tried to make the behavior synchronous a while ago but that led to
lockdep splats. Waiman took another stab at cleaning up and making it
synchronous. The patch has been in -next for well over a month and
there haven't been any complaints, so fingers crossed.
- Tracepoints added to help understanding rstat lock contentions.
- A bunch of minor changes - doc updates, code cleanups and selftests.
* tag 'cgroup-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (24 commits)
cgroup/rstat: add cgroup_rstat_cpu_lock helpers and tracepoints
selftests/cgroup: Drop define _GNU_SOURCE
docs: cgroup-v1: Update page cache removal functions
selftests/cgroup: fix uninitialized variables in test_zswap.c
selftests/cgroup: cpu_hogger init: use {} instead of {NULL}
selftests/cgroup: fix clang warnings: uninitialized fd variable
selftests/cgroup: fix clang build failures for abs() calls
cgroup/cpuset: Remove outdated comment in sched_partition_write()
cgroup/cpuset: Fix incorrect top_cpuset flags
cgroup/cpuset: Avoid clearing CS_SCHED_LOAD_BALANCE twice
cgroup/cpuset: Statically initialize more members of top_cpuset
cgroup: Avoid unnecessary looping in cgroup_no_v1()
cgroup, legacy_freezer: update comment for freezer_css_offline()
docs, cgroup: add entries for pids to cgroup-v2.rst
cgroup: don't call cgroup1_pidlist_destroy_all() for v2
cgroup_freezer: update comment for freezer_css_online()
cgroup/rstat: desc member cgrp in cgroup_rstat_flush_release
cgroup/rstat: add cgroup_rstat_lock helpers and tracepoints
cgroup/pids: Remove superfluous zeroing
docs: cgroup-v1: Fix description for css_online
...
Diffstat (limited to 'Documentation/admin-guide/cgroup-v2.rst')
-rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index eaf9e66e472a..f554df7ac649 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1058,12 +1058,15 @@ cpufreq governor about the minimum desired frequency which should always be provided by a CPU, as well as the maximum desired frequency, which should not be exceeded by a CPU. -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. +WARNING: cgroup2 doesn't yet support control of realtime processes. For +a kernel built with the CONFIG_RT_GROUP_SCHED option enabled for group +scheduling of realtime processes, the cpu controller can only be enabled +when all RT processes are in the root cgroup. This limitation does +not apply if CONFIG_RT_GROUP_SCHED is disabled. 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 +with a CONFIG_RT_GROUP_SCHED enabled kernel. CPU Interface Files @@ -2190,11 +2193,25 @@ PID Interface Files Hard limit of number of processes. pids.current - A read-only single value file which exists on all cgroups. + A read-only single value file which exists on non-root cgroups. The number of processes currently in the cgroup and its descendants. + pids.peak + A read-only single value file which exists on non-root cgroups. + + The maximum value that the number of processes in the cgroup and its + descendants has ever reached. + + pids.events + A read-only flat-keyed file which exists on non-root cgroups. The + following entries are defined. Unless specified otherwise, a value + change in this file generates a file modified event. + + max + Number of times fork failed because limit was hit. + Organisational operations are not blocked by cgroup policies, so it is possible to have pids.current > pids.max. This can be done by either setting the limit to be smaller than pids.current, or attaching enough |