Tejun Heo 671c11f061 cgroup: Elide write-locking threadgroup_rwsem when updating csses on an empty subtree ... cgroup_update_dfl_csses() write-lock the threadgroup_rwsem as updating the csses can trigger process migrations. However, if the subtree doesn't contain any tasks, there aren't gonna be any cgroup migrations. This condition can be trivially detected by testing whether mgctx.preloaded_src_csets is empty. Elide write-locking threadgroup_rwsem if the subtree is empty. After this optimization, the usage pattern of creating a cgroup, enabling the necessary controllers, and then seeding it with CLONE_INTO_CGROUP and then removing the cgroup after it becomes empty doesn't need to write-lock threadgroup_rwsem at all. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Michal Koutný <mkoutny@suse.com>		2022-07-22 19:12:37 -10:00
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cgroup-internal.h	cgroup: Make cgroup_debug static	2022-05-18 06:59:20 -10:00
cgroup-v1.c	cgroup-v1: Correct privileges check in release_agent writes	2022-02-22 08:12:22 -10:00
cgroup.c	cgroup: Elide write-locking threadgroup_rwsem when updating csses on an empty subtree	2022-07-22 19:12:37 -10:00
cpuset.c	cgroup/cpuset: Remove cpus_allowed/mems_allowed setup in cpuset_init_smp()	2022-05-05 08:57:00 -10:00
debug.c	kernel: cgroup: fix misuse of %x	2019-05-06 08:47:48 -07:00
freezer.c	cgroup: cleanup comments	2022-03-13 19:19:27 -10:00
legacy_freezer.c	cgroup: rename freezer.c into legacy_freezer.c	2019-04-19 11:26:48 -07:00
Makefile	cgroup: Add misc cgroup controller	2021-04-04 13:34:46 -04:00
misc.c	misc_cgroup: remove error log to avoid log flood	2021-09-20 07:35:38 -10:00
namespace.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
pids.c	clone3: allow spawning processes into cgroups	2020-02-12 17:57:51 -05:00
rdma.c	cgroup: fix spelling mistakes	2021-05-24 12:45:26 -04:00
rstat.c	Merge branch 'akpm' (patches from Andrew)	2022-03-24 14:14:07 -07:00