From: Shaohua Li <shli@kernel.org>
To: linux-raid@vger.kernel.org
Cc: neilb@suse.de, axboe@kernel.dk, dan.j.williams@intel.com,
shli@fusionio.com
Subject: [patch 8/9 v2] raid5: raid5d handle stripe in batch way
Date: Tue, 19 Jun 2012 09:59:49 +0800 [thread overview]
Message-ID: <20120619020150.973797041@kernel.org> (raw)
In-Reply-To: 20120619015941.891400722@kernel.org
[-- Attachment #1: raid5-raid5d-fetch-stripe-batch.patch --]
[-- Type: text/plain, Size: 2330 bytes --]
Let raid5d handle stripe in batch way to reduce conf->device_lock locking.
Signed-off-by: Shaohua Li <shli@fusionio.com>
---
drivers/md/raid5.c | 45 ++++++++++++++++++++++++++++++++-------------
1 file changed, 32 insertions(+), 13 deletions(-)
Index: linux/drivers/md/raid5.c
===================================================================
--- linux.orig/drivers/md/raid5.c 2012-06-18 08:34:54.735195847 +0800
+++ linux/drivers/md/raid5.c 2012-06-18 08:36:47.833775907 +0800
@@ -4563,6 +4563,30 @@ static int retry_aligned_read(struct r5
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.
@@ -4573,7 +4597,6 @@ static int retry_aligned_read(struct r5
*/
static void raid5d(struct mddev *mddev)
{
- struct stripe_head *sh;
struct r5conf *conf = mddev->private;
int handled;
struct blk_plug plug;
@@ -4587,6 +4610,7 @@ static void raid5d(struct mddev *mddev)
spin_lock_irq(&conf->device_lock);
while (1) {
struct bio *bio;
+ int batch_size;
if (atomic_read(&mddev->plug_cnt) == 0 &&
!list_empty(&conf->bitmap_list)) {
@@ -4611,21 +4635,16 @@ 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);
next prev parent reply other threads:[~2012-06-19 1:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 1:59 [patch 0/9 v2] raid5: improve write performance for fast storage Shaohua Li
2012-06-19 1:59 ` [patch 1/9 v2] raid5: use wake_up_all for overlap waking Shaohua Li
2012-06-19 1:59 ` [patch 2/9 v2] raid5: add a per-stripe lock Shaohua Li
2012-06-19 1:59 ` [patch 3/9 v2] raid5: lockless access raid5 overrided bi_phys_segments Shaohua Li
2012-06-21 1:56 ` Dan Williams
2012-06-19 1:59 ` [patch 4/9 v2] raid5: remove some device_lock locking places Shaohua Li
2012-06-19 1:59 ` [patch 5/9 v2] raid5: reduce chance release_stripe() taking device_lock Shaohua Li
2012-06-21 0:56 ` Dan Williams
2012-06-21 1:34 ` Shaohua Li
2012-06-19 1:59 ` [patch 6/9 v2] md: personality can provide unplug private data Shaohua Li
2012-06-19 1:59 ` [patch 7/9 v2] raid5: make_request use batch stripe release Shaohua Li
2012-06-19 1:59 ` Shaohua Li [this message]
2012-06-19 1:59 ` [patch 9/9 v2] raid5: create multiple threads to handle stripes Shaohua Li
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