padata: Block until the instance is unused on stop
This patch makes padata_stop to block until the padata
instance is unused. Also we split padata_stop to a locked
and a unlocked version. This is in preparation to be able
to change the cpumask after a call to patata stop.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/kernel/padata.c b/kernel/padata.c
index e7d723a..9e18dfa 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -490,6 +490,20 @@
pinst->flags |= PADATA_INIT;
}
+static void __padata_stop(struct padata_instance *pinst)
+{
+ if (!(pinst->flags & PADATA_INIT))
+ return;
+
+ pinst->flags &= ~PADATA_INIT;
+
+ synchronize_rcu();
+
+ get_online_cpus();
+ padata_flush_queues(pinst->pd);
+ put_online_cpus();
+}
+
/* Replace the internal control stucture with a new one. */
static void padata_replace(struct padata_instance *pinst,
struct parallel_data *pd_new)
@@ -649,7 +663,7 @@
void padata_stop(struct padata_instance *pinst)
{
mutex_lock(&pinst->lock);
- pinst->flags &= ~PADATA_INIT;
+ __padata_stop(pinst);
mutex_unlock(&pinst->lock);
}
EXPORT_SYMBOL(padata_stop);
@@ -770,17 +784,11 @@
*/
void padata_free(struct padata_instance *pinst)
{
- padata_stop(pinst);
-
- synchronize_rcu();
-
#ifdef CONFIG_HOTPLUG_CPU
unregister_hotcpu_notifier(&pinst->cpu_notifier);
#endif
- get_online_cpus();
- padata_flush_queues(pinst->pd);
- put_online_cpus();
+ padata_stop(pinst);
padata_free_pd(pinst->pd);
free_cpumask_var(pinst->cpumask);
kfree(pinst);