Messages in this thread Patch in this message | | | From | Juri Lelli <> | Subject | [RFC PATCH 3/3] cgroup/cpuset: Iterate only if DEADLINE tasks are present | Date | Wed, 15 Mar 2023 12:18:12 +0000 |
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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> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> --- kernel/cgroup/cpuset.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 57bc60112618..f46192d2e97e 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1090,6 +1090,9 @@ static void 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))) -- 2.39.2
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