raid5: relieve lock contention in get_active_stripe()
track empty inactive list count, so md_raid5_congested() can use it to make
decision.
Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index a9e443a..e440738 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -475,6 +475,7 @@
*/
atomic_t active_stripes;
struct list_head inactive_list[NR_STRIPE_HASH_LOCKS];
+ atomic_t empty_inactive_list_nr;
struct llist_head released_stripes;
wait_queue_head_t wait_for_stripe;
wait_queue_head_t wait_for_overlap;
