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-rw-r--r--kernel/workqueue.c29
1 files changed, 27 insertions, 2 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d79a18d..dc7b845 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1326,6 +1326,15 @@ static void idle_worker_rebind(struct worker *worker)
/* we did our part, wait for rebind_workers() to finish up */
wait_event(gcwq->rebind_hold, !(worker->flags & WORKER_REBIND));
+
+ /*
+ * rebind_workers() shouldn't finish until all workers passed the
+ * above WORKER_REBIND wait. Tell it when done.
+ */
+ spin_lock_irq(&worker->pool->gcwq->lock);
+ if (!--worker->idle_rebind->cnt)
+ complete(&worker->idle_rebind->done);
+ spin_unlock_irq(&worker->pool->gcwq->lock);
}
/*
@@ -1448,12 +1457,28 @@ retry:
* be cleared inside idle_worker_rebind(). Clear and release.
* Clearing %WORKER_REBIND from this foreign context is safe
* because these workers are still guaranteed to be idle.
+ *
+ * We need to make sure all idle workers passed WORKER_REBIND wait
+ * in idle_worker_rebind() before returning; otherwise, workers can
+ * get stuck at the wait if hotplug cycle repeats.
*/
- for_each_worker_pool(pool, gcwq)
- list_for_each_entry(worker, &pool->idle_list, entry)
+ idle_rebind.cnt = 1;
+ INIT_COMPLETION(idle_rebind.done);
+
+ for_each_worker_pool(pool, gcwq) {
+ list_for_each_entry(worker, &pool->idle_list, entry) {
worker->flags &= ~WORKER_REBIND;
+ idle_rebind.cnt++;
+ }
+ }
wake_up_all(&gcwq->rebind_hold);
+
+ if (--idle_rebind.cnt) {
+ spin_unlock_irq(&gcwq->lock);
+ wait_for_completion(&idle_rebind.done);
+ spin_lock_irq(&gcwq->lock);
+ }
}
static struct worker *alloc_worker(void)
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