As cpuset is updating HK_TYPE_DOMAIN housekeeping mask when there is a change in the set of isolated CPUs, making this change is now more costly than before. Right now, the isolated_cpus_updating flag can be set even if there is no real change in isolated_cpus. Put in additional checks to make sure that isolated_cpus_updating is set only if there is a real change in isolated_cpus.
Signed-off-by: Waiman Long <[email protected]> --- kernel/cgroup/cpuset.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index e55855269432..c792380f9b60 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1180,11 +1180,15 @@ static void isolated_cpus_update(int old_prs, int new_prs, struct cpumask *xcpus WARN_ON_ONCE(old_prs == new_prs); lockdep_assert_held(&callback_lock); lockdep_assert_held(&cpuset_mutex); - if (new_prs == PRS_ISOLATED) + if (new_prs == PRS_ISOLATED) { + if (cpumask_subset(xcpus, isolated_cpus)) + return; cpumask_or(isolated_cpus, isolated_cpus, xcpus); - else + } else { + if (!cpumask_intersects(xcpus, isolated_cpus)) + return; cpumask_andnot(isolated_cpus, isolated_cpus, xcpus); - + } isolated_cpus_updating = true; } -- 2.52.0
