bfbacc2ef7
[ Upstream commit 671c11f0619e5ccb380bcf0f062f69ba95fc974a ] 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> Signed-off-by: Sasha Levin <sashal@kernel.org> |
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| .. | ||
| cgroup-internal.h | ||
| cgroup-v1.c | ||
| cgroup.c | ||
| cpuset.c | ||
| debug.c | ||
| freezer.c | ||
| legacy_freezer.c | ||
| Makefile | ||
| namespace.c | ||
| pids.c | ||
| rdma.c | ||
| rstat.c | ||