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authorShaohua Li <shli@kernel.org>2012-08-02 08:33:15 +1000
committerNeilBrown <neilb@suse.de>2012-08-02 08:33:15 +1000
commit46a06401f6ba13e59d24746fa9ffa6773b69eee3 (patch)
treef6d938b79aed14b7a51cda5a607e09f8226feb03 /drivers/md/raid5.c
parent8811b5968f6216e97ccb9fe7b9883af39e339921 (diff)
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 <shli@fusionio.com> Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c45
1 files changed, 32 insertions, 13 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 978ba9b7a3c..9e41ae37bd4 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<<MD_CHANGE_PENDING))
+ if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) {
+ spin_unlock_irq(&conf->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);