Messages in this thread | | | Date | Tue, 26 Jul 2022 16:31:56 +0200 | From | Michal Koutný <> | Subject | Re: [PATCH 1/3 cgroup/for-5.20] cgroup: Elide write-locking threadgroup_rwsem when updating csses on an empty subtree |
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Hello.
On Thu, Jul 14, 2022 at 06:38:15PM -1000, Tejun Heo <tj@kernel.org> wrote: > However, if the subtree doesn't contain any tasks, there aren't gonna > be any cgroup migrations.
Nice catch.
> 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.
This check is perhaps even more robust than, e.g. cgroup_is_populated() due to possible zombie cases.
> kernel/cgroup/cgroup.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-)
Reviewed-by: Michal Koutný <mkoutny@suse.com> [unhandled content-type:application/pgp-signature] | |