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| author | Waiman Long <longman@redhat.com> | 2023-03-17 16:15:07 +0100 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2023-03-29 20:42:09 +0200 |
| commit | 6667439f51c446fead5d991ff49b842a811a6195 (patch) | |
| tree | e771e8f5dff7e00d0db60b364f39a1a70e8a32e6 /kernel/cgroup/cpuset.c | |
| parent | cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset (diff) | |
| download | linux-6667439f51c446fead5d991ff49b842a811a6195.tar.xz linux-6667439f51c446fead5d991ff49b842a811a6195.zip | |
cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated
Similar to commit 3fb906e7fabb ("group/cpuset: Don't filter offline
CPUs in cpuset_cpus_allowed() for top cpuset tasks"), the whole set of
possible CPUs including offline ones should be used for setting cpumasks
for tasks in the top cpuset when a cpuset partition is modified as the
hotplug code won't update cpumasks for tasks in the top cpuset when
CPUs become online or offline.
Signed-off-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 | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index a05bc93215ac..bc4dcfd7bee5 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1209,7 +1209,9 @@ void rebuild_sched_domains(void) * * Iterate through each task of @cs updating its cpus_allowed to the * effective cpuset's. As this function is called with cpuset_rwsem held, - * cpuset membership stays stable. + * cpuset membership stays stable. For top_cpuset, task_cpu_possible_mask() + * is used instead of effective_cpus to make sure all offline CPUs are also + * included as hotplug code won't update cpumasks for tasks in top_cpuset. */ static void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus) { @@ -1219,15 +1221,18 @@ static void update_tasks_cpumask(struct cpuset *cs, struct cpumask *new_cpus) css_task_iter_start(&cs->css, 0, &it); while ((task = css_task_iter_next(&it))) { - /* - * Percpu kthreads in top_cpuset are ignored - */ - if (top_cs && (task->flags & PF_KTHREAD) && - kthread_is_per_cpu(task)) - continue; + const struct cpumask *possible_mask = task_cpu_possible_mask(task); - cpumask_and(new_cpus, cs->effective_cpus, - task_cpu_possible_mask(task)); + if (top_cs) { + /* + * Percpu kthreads in top_cpuset are ignored + */ + if ((task->flags & PF_KTHREAD) && kthread_is_per_cpu(task)) + continue; + cpumask_andnot(new_cpus, possible_mask, cs->subparts_cpus); + } else { + cpumask_and(new_cpus, possible_mask, cs->effective_cpus); + } set_cpus_allowed_ptr(task, new_cpus); } css_task_iter_end(&it); |