From 46a06401f6ba13e59d24746fa9ffa6773b69eee3 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Thu, 2 Aug 2012 08:33:15 +1000 Subject: [PATCH] raid5: raid5d handle stripe in batch way Let raid5d handle stripe in batch way to reduce conf->device_lock locking. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown --- drivers/md/raid5.c | 45 ++++++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 13 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 978ba9b..9e41ae3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4574,6 +4574,30 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) return handled; } +#define MAX_STRIPE_BATCH 8 +static int handle_active_stripes(struct r5conf *conf) +{ + struct stripe_head *batch[MAX_STRIPE_BATCH], *sh; + int i, batch_size = 0; + + while (batch_size < MAX_STRIPE_BATCH && + (sh = __get_priority_stripe(conf)) != NULL) + batch[batch_size++] = sh; + + if (batch_size == 0) + return batch_size; + spin_unlock_irq(&conf->device_lock); + + for (i = 0; i < batch_size; i++) + handle_stripe(batch[i]); + + cond_resched(); + + spin_lock_irq(&conf->device_lock); + for (i = 0; i < batch_size; i++) + __release_stripe(conf, batch[i]); + return batch_size; +} /* * This is our raid5 kernel thread. @@ -4584,7 +4608,6 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) */ static void raid5d(struct mddev *mddev) { - struct stripe_head *sh; struct r5conf *conf = mddev->private; int handled; struct blk_plug plug; @@ -4598,6 +4621,7 @@ static void raid5d(struct mddev *mddev) spin_lock_irq(&conf->device_lock); while (1) { struct bio *bio; + int batch_size; if ( !list_empty(&conf->bitmap_list)) { @@ -4621,21 +4645,16 @@ static void raid5d(struct mddev *mddev) handled++; } - sh = __get_priority_stripe(conf); - - if (!sh) + batch_size = handle_active_stripes(conf); + if (!batch_size) break; - spin_unlock_irq(&conf->device_lock); - - handled++; - handle_stripe(sh); - release_stripe(sh); - cond_resched(); + handled += batch_size; - if (mddev->flags & ~(1<flags & ~(1<device_lock); md_check_recovery(mddev); - - spin_lock_irq(&conf->device_lock); + spin_lock_irq(&conf->device_lock); + } } pr_debug("%d stripes handled\n", handled); -- 2.7.4