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)
{
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;
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;