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| author | Peter Zijlstra <peterz@infradead.org> | 2021-01-12 11:26:49 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-01-22 15:09:42 +0100 |
| commit | 5c25b5ff89f004c30b04759dc34ace8585a4085f (patch) | |
| tree | a2132a7d24a2e50ef4d3703f3c00dbb55ce7a44e /kernel | |
| parent | kthread: Extract KTHREAD_IS_PER_CPU (diff) | |
| download | linux-5c25b5ff89f004c30b04759dc34ace8585a4085f.tar.xz linux-5c25b5ff89f004c30b04759dc34ace8585a4085f.zip | |
workqueue: Tag bound workers with KTHREAD_IS_PER_CPU
Mark the per-cpu workqueue workers as KTHREAD_IS_PER_CPU.
Workqueues have unfortunate semantics in that per-cpu workers are not
default flushed and parked during hotplug, however a subset does
manual flush on hotplug and hard relies on them for correctness.
Therefore play silly games..
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/20210121103506.693465814@infradead.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/workqueue.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1646331546eb..cce34336fbd7 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1861,6 +1861,8 @@ static void worker_attach_to_pool(struct worker *worker, */ if (pool->flags & POOL_DISASSOCIATED) worker->flags |= WORKER_UNBOUND; + else + kthread_set_per_cpu(worker->task, pool->cpu); list_add_tail(&worker->node, &pool->workers); worker->pool = pool; @@ -1883,6 +1885,7 @@ static void worker_detach_from_pool(struct worker *worker) mutex_lock(&wq_pool_attach_mutex); + kthread_set_per_cpu(worker->task, -1); list_del(&worker->node); worker->pool = NULL; @@ -4919,8 +4922,10 @@ static void unbind_workers(int cpu) raw_spin_unlock_irq(&pool->lock); - for_each_pool_worker(worker, pool) + for_each_pool_worker(worker, pool) { + kthread_set_per_cpu(worker->task, -1); WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, cpu_possible_mask) < 0); + } mutex_unlock(&wq_pool_attach_mutex); @@ -4972,9 +4977,11 @@ static void rebind_workers(struct worker_pool *pool) * of all workers first and then clear UNBOUND. As we're called * from CPU_ONLINE, the following shouldn't fail. */ - for_each_pool_worker(worker, pool) + for_each_pool_worker(worker, pool) { + kthread_set_per_cpu(worker->task, pool->cpu); WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, pool->attrs->cpumask) < 0); + } raw_spin_lock_irq(&pool->lock); |