padata: Flush the padata queues actively

yield was used to wait until all references of the internal control structure in use are dropped before it is freed. This patch implements padata_flush_queues which actively flushes the padata percpu queues in this case. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

padata: Flush the padata queues actively
yield was used to wait until all references of the internal control structure in use are dropped before it is freed. This patch implements padata_flush_queues which actively flushes the padata percpu queues in this case. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Steffen Klassert · Herbert Xu
1 parent d46a5ac7a7
Showing 1 changed file with 25 additions and 8 deletions Side-by-side Diff
kernel/padata.c
@@ -417,6 +417,29 @@
 	kfree(pd);
 }
  
+static void padata_flush_queues(struct parallel_data *pd)
+{
+	int cpu;
+	struct padata_queue *queue;
+
+	for_each_cpu(cpu, pd->cpumask) {
+		queue = per_cpu_ptr(pd->queue, cpu);
+		flush_work(&queue->pwork);
+	}
+
+	del_timer_sync(&pd->timer);
+
+	if (atomic_read(&pd->reorder_objects))
+		padata_reorder(pd);
+
+	for_each_cpu(cpu, pd->cpumask) {
+		queue = per_cpu_ptr(pd->queue, cpu);
+		flush_work(&queue->swork);
+	}
+
+	BUG_ON(atomic_read(&pd->refcnt) != 0);
+}
+
 static void padata_replace(struct padata_instance *pinst,
 			   struct parallel_data *pd_new)
 {
@@ -428,11 +451,7 @@
  
 	synchronize_rcu();
  
-	while (atomic_read(&pd_old->refcnt) != 0)
-		yield();
-
-	flush_workqueue(pinst->wq);
-
+	padata_flush_queues(pd_old);
 	padata_free_pd(pd_old);
  
 	pinst->flags &= ~PADATA_RESET;
  
@@ -695,12 +714,10 @@
  
 	synchronize_rcu();
  
-	while (atomic_read(&pinst->pd->refcnt) != 0)
-		yield();
-
 #ifdef CONFIG_HOTPLUG_CPU
 	unregister_hotcpu_notifier(&pinst->cpu_notifier);
 #endif
+	padata_flush_queues(pinst->pd);
 	padata_free_pd(pinst->pd);
 	free_cpumask_var(pinst->cpumask);
 	kfree(pinst);
...	...	@@ -417,6 +417,29 @@
417	417	kfree(pd);
418	418	}
419	419
	420	+static void padata_flush_queues(struct parallel_data *pd)
	421	+{
	422	+ int cpu;
	423	+ struct padata_queue *queue;
	424	+
	425	+ for_each_cpu(cpu, pd->cpumask) {
	426	+ queue = per_cpu_ptr(pd->queue, cpu);
	427	+ flush_work(&queue->pwork);
	428	+ }
	429	+
	430	+ del_timer_sync(&pd->timer);
	431	+
	432	+ if (atomic_read(&pd->reorder_objects))
	433	+ padata_reorder(pd);
	434	+
	435	+ for_each_cpu(cpu, pd->cpumask) {
	436	+ queue = per_cpu_ptr(pd->queue, cpu);
	437	+ flush_work(&queue->swork);
	438	+ }
	439	+
	440	+ BUG_ON(atomic_read(&pd->refcnt) != 0);
	441	+}
	442	+
420	443	static void padata_replace(struct padata_instance *pinst,
421	444	struct parallel_data *pd_new)
422	445	{
...	...	@@ -428,11 +451,7 @@
428	451
429	452	synchronize_rcu();
430	453
431		- while (atomic_read(&pd_old->refcnt) != 0)
432		- yield();
433		-
434		- flush_workqueue(pinst->wq);
435		-
	454	+ padata_flush_queues(pd_old);
436	455	padata_free_pd(pd_old);
437	456
438	457	pinst->flags &= ~PADATA_RESET;
439	458
...	...	@@ -695,12 +714,10 @@
695	714
696	715	synchronize_rcu();
697	716
698		- while (atomic_read(&pinst->pd->refcnt) != 0)
699		- yield();
700		-
701	717	#ifdef CONFIG_HOTPLUG_CPU
702	718	unregister_hotcpu_notifier(&pinst->cpu_notifier);
703	719	#endif
	720	+ padata_flush_queues(pinst->pd);
704	721	padata_free_pd(pinst->pd);
705	722	free_cpumask_var(pinst->cpumask);
706	723	kfree(pinst);