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>
This commit is contained in:
Steffen Klassert 2010-07-07 15:30:47 +02:00 committed by Herbert Xu
parent 4c87917029
commit ee83655512

View file

@ -490,6 +490,20 @@ static void __padata_start(struct padata_instance *pinst)
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 @@ EXPORT_SYMBOL(padata_start);
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 @@ EXPORT_SYMBOL(padata_alloc);
*/
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);