diff options
| -rw-r--r-- | block/blk-cgroup.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 7b06a5fa3cac..575d7a2e7203 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -56,6 +56,8 @@ static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */ bool blkcg_debug_stats = false; static struct workqueue_struct *blkcg_punt_bio_wq; +#define BLKG_DESTROY_BATCH_SIZE 64 + static bool blkcg_policy_enabled(struct request_queue *q, const struct blkcg_policy *pol) { @@ -422,7 +424,9 @@ static void blkg_destroy(struct blkcg_gq *blkg) static void blkg_destroy_all(struct request_queue *q) { struct blkcg_gq *blkg, *n; + int count = BLKG_DESTROY_BATCH_SIZE; +restart: spin_lock_irq(&q->queue_lock); list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) { struct blkcg *blkcg = blkg->blkcg; @@ -430,6 +434,17 @@ static void blkg_destroy_all(struct request_queue *q) spin_lock(&blkcg->lock); blkg_destroy(blkg); spin_unlock(&blkcg->lock); + + /* + * in order to avoid holding the spin lock for too long, release + * it when a batch of blkgs are destroyed. + */ + if (!(--count)) { + count = BLKG_DESTROY_BATCH_SIZE; + spin_unlock_irq(&q->queue_lock); + cond_resched(); + goto restart; + } } q->root_blkg = NULL; |