diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2021-01-15 19:08:36 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-07 15:35:49 +0100 |
| commit | b1a1c262e4b0e713e52c63bd3233f1b9d6f2f056 (patch) | |
| tree | 7296c2ff957794eac56dca0edb301cb7f5d5f285 | |
| parent | 5b1e4fc2984eab30c5fffbf2bd1f016577cadab6 (diff) | |
workqueue: Restrict affinity change to rescuer
[ Upstream commit 640f17c82460e9724fd256f0a1f5d99e7ff0bda4 ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 28e52657e093..29c36c029062 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1848,12 +1848,6 @@ 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. @@ -1861,6 +1855,9 @@ static void worker_attach_to_pool(struct worker *worker, if (pool->flags & POOL_DISASSOCIATED) worker->flags |= WORKER_UNBOUND; + if (worker->rescue_wq) + set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask); + list_add_tail(&worker->node, &pool->workers); worker->pool = pool; |