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| author | Juri Lelli <juri.lelli@redhat.com> | 2023-05-08 09:58:52 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2023-05-08 13:22:33 -1000 |
| commit | c0f78fd5edcf29b2822ac165f9248a6c165e8554 (patch) | |
| tree | d762a1991f8ea08d021c703d0642830988077fff /kernel/cgroup/cpuset.c | |
| parent | 6c24849f5515e4966d94fa5279bdff4acf2e9489 (diff) | |
| download | lwn-c0f78fd5edcf29b2822ac165f9248a6c165e8554.tar.gz lwn-c0f78fd5edcf29b2822ac165f9248a6c165e8554.zip | |
cgroup/cpuset: Iterate only if DEADLINE tasks are present
update_tasks_root_domain currently iterates over all tasks even if no
DEADLINE task is present on the cpuset/root domain for which bandwidth
accounting is being rebuilt. This has been reported to introduce 10+ ms
delays on suspend-resume operations.
Skip the costly iteration for cpusets that don't contain DEADLINE tasks.
Reported-by: Qais Yousef <qyousef@layalina.io>
Link: https://lore.kernel.org/lkml/20230206221428.2125324-1-qyousef@layalina.io/
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup/cpuset.c')
| -rw-r--r-- | kernel/cgroup/cpuset.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index ca195ff8b298..b7168970fff2 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1092,6 +1092,9 @@ static void dl_update_tasks_root_domain(struct cpuset *cs) struct css_task_iter it; struct task_struct *task; + if (cs->nr_deadline_tasks == 0) + return; + css_task_iter_start(&cs->css, 0, &it); while ((task = css_task_iter_next(&it))) |