diff options
| author | Shaohua Li <shli@kernel.org> | 2013-11-14 15:16:17 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2013-11-19 15:18:22 +1100 |
| commit | 4bda556aea1d2916260326c6afa77b84a1f1345a (patch) | |
| tree | 5233a0470d29eb5976ec9f6296ef129adf097ed8 | |
| parent | 566c09c53455d7c4f1130928ef8071da1a24ea65 (diff) | |
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>
| -rw-r--r-- | drivers/md/raid5.c | 8 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 1 |
2 files changed, 8 insertions, 1 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 93090b2afab4..1fb28c56457a 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -356,6 +356,9 @@ static void release_inactive_stripe_list(struct r5conf *conf, */ if (!list_empty_careful(list)) { spin_lock_irqsave(conf->hash_locks + hash, flags); + if (list_empty(conf->inactive_list + hash) && + !list_empty(list)) + atomic_dec(&conf->empty_inactive_list_nr); list_splice_tail_init(list, conf->inactive_list + hash); do_wakeup = true; spin_unlock_irqrestore(conf->hash_locks + hash, flags); @@ -477,6 +480,8 @@ static struct stripe_head *get_free_stripe(struct r5conf *conf, int hash) remove_hash(sh); atomic_inc(&conf->active_stripes); BUG_ON(hash != sh->hash_lock_index); + if (list_empty(conf->inactive_list + hash)) + atomic_inc(&conf->empty_inactive_list_nr); out: return sh; } @@ -4059,7 +4064,7 @@ int md_raid5_congested(struct mddev *mddev, int bits) return 1; if (conf->quiesce) return 1; - if (atomic_read(&conf->active_stripes) == conf->max_nr_stripes) + if (atomic_read(&conf->empty_inactive_list_nr)) return 1; return 0; @@ -5750,6 +5755,7 @@ static struct r5conf *setup_conf(struct mddev *mddev) memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024; + atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS); if (grow_stripes(conf, NR_STRIPES)) { printk(KERN_ERR "md/raid:%s: couldn't allocate %dkB for buffers\n", diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index a9e443a1116f..e4407388670a 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -475,6 +475,7 @@ struct r5conf { */ 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; |