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| author | Peter Zijlstra <peterz@infradead.org> | 2021-01-15 19:08:36 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-01-22 15:09:43 +0100 |
| commit | 640f17c82460e9724fd256f0a1f5d99e7ff0bda4 (patch) | |
| tree | 843671442486fff2c92b7b7df424524a2f4fd96a /kernel | |
| parent | workqueue: Tag bound workers with KTHREAD_IS_PER_CPU (diff) | |
| download | linux-640f17c82460e9724fd256f0a1f5d99e7ff0bda4.tar.xz linux-640f17c82460e9724fd256f0a1f5d99e7ff0bda4.zip | |
workqueue: Restrict affinity change to rescuer
create_worker() will already set the right affinity using
kthread_bind_mask(), this means only the rescuer will need to change
it's affinity.
Howveer, while in cpu-hot-unplug a regular task is not allowed to run
on online&&!active as it would be pushed away quite agressively. We
need KTHREAD_IS_PER_CPU to survive in that environment.
Therefore set the affinity after getting that magic flag.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210121103506.826629830@infradead.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/workqueue.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index cce34336fbd7..894bb885b40b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1849,12 +1849,6 @@ static void worker_attach_to_pool(struct worker *worker, mutex_lock(&wq_pool_attach_mutex); /* - * set_cpus_allowed_ptr() will fail if the cpumask doesn't have any - * online CPUs. It'll be re-applied when any of the CPUs come up. - */ - set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); - - /* * The wq_pool_attach_mutex ensures %POOL_DISASSOCIATED remains * stable across this function. See the comments above the flag * definition for details. @@ -1864,6 +1858,9 @@ static void worker_attach_to_pool(struct worker *worker, else kthread_set_per_cpu(worker->task, pool->cpu); + if (worker->rescue_wq) + set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); + list_add_tail(&worker->node, &pool->workers); worker->pool = pool; |