From: NeilBrown <neilb@suse.de>
To: Shaohua Li <shli@kernel.org>
Cc: linux-raid@vger.kernel.org, axboe@kernel.dk,
dan.j.williams@intel.com, shli@fusionio.com
Subject: Re: [patch 09/10 v3] raid5: raid5d handle stripe in batch way
Date: Mon, 2 Jul 2012 12:32:59 +1000 [thread overview]
Message-ID: <20120702123259.3487dbb8@notabene.brown> (raw)
In-Reply-To: <20120625072712.004553385@kernel.org>
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On Mon, 25 Jun 2012 15:24:56 +0800 Shaohua Li <shli@kernel.org> wrote:
> 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 2012-06-25 14:38:37.378835415 +0800
> +++ linux/drivers/md/raid5.c 2012-06-25 14:38:40.150800523 +0800
> @@ -4568,6 +4568,30 @@ 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.
> @@ -4578,7 +4602,6 @@ 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;
> @@ -4592,6 +4615,7 @@ 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)) {
> @@ -4616,21 +4640,16 @@ 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);
>
>
I've applied this patch, thanks.
NeilBrown
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next prev parent reply other threads:[~2012-07-02 2:32 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-25 7:24 [patch 00/10 v3] raid5: improve write performance for fast storage Shaohua Li
2012-06-25 7:24 ` [patch 01/10 v3] raid5: use wake_up_all for overlap waking Shaohua Li
2012-06-28 7:26 ` NeilBrown
2012-06-28 8:53 ` Shaohua Li
2012-06-25 7:24 ` [patch 02/10 v3] raid5: delayed stripe fix Shaohua Li
2012-07-02 0:46 ` NeilBrown
2012-07-02 0:49 ` Shaohua Li
2012-07-02 0:55 ` NeilBrown
2012-06-25 7:24 ` [patch 03/10 v3] raid5: add a per-stripe lock Shaohua Li
2012-07-02 0:50 ` NeilBrown
2012-07-02 3:16 ` Shaohua Li
2012-07-02 7:39 ` NeilBrown
2012-07-03 1:27 ` Shaohua Li
2012-07-03 12:16 ` majianpeng
2012-07-03 23:56 ` NeilBrown
2012-07-04 1:09 ` majianpeng
2012-06-25 7:24 ` [patch 04/10 v3] raid5: lockless access raid5 overrided bi_phys_segments Shaohua Li
2012-06-25 7:24 ` [patch 05/10 v3] raid5: remove some device_lock locking places Shaohua Li
2012-06-25 7:24 ` [patch 06/10 v3] raid5: reduce chance release_stripe() taking device_lock Shaohua Li
2012-07-02 0:57 ` NeilBrown
2012-06-25 7:24 ` [patch 07/10 v3] md: personality can provide unplug private data Shaohua Li
2012-07-02 1:06 ` NeilBrown
2012-06-25 7:24 ` [patch 08/10 v3] raid5: make_request use batch stripe release Shaohua Li
2012-07-02 2:31 ` NeilBrown
2012-07-02 2:59 ` Shaohua Li
2012-07-02 5:07 ` NeilBrown
2012-06-25 7:24 ` [patch 09/10 v3] raid5: raid5d handle stripe in batch way Shaohua Li
2012-07-02 2:32 ` NeilBrown [this message]
2012-06-25 7:24 ` [patch 10/10 v3] raid5: create multiple threads to handle stripes Shaohua Li
2012-07-02 2:39 ` NeilBrown
2012-07-02 20:03 ` Dan Williams
2012-07-03 8:04 ` Shaohua Li
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