Re: [PATCH] md:raid1/10: avoid unnecessary locking
From: NeilBrown <hidden>
Date: 2017-05-11 22:29:56
On Wed, May 10 2017, shli@kernel.org wrote:
From: Shaohua Li <redacted> If we add bios to block plugging list, locking is unnecessry, since the block unplug is guaranteed not to run at that time.
Yes, that make sense. Thanks Reviewed-by: NeilBrown <redacted>
quoted hunk ↗ jump to hunk
Cc: NeilBrown <redacted> Signed-off-by: Shaohua Li <redacted> --- drivers/md/raid1.c | 7 +++---- drivers/md/raid10.c | 7 +++---- 2 files changed, 6 insertions(+), 8 deletions(-)diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 7c1f73398800..a17ed6218d51 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c@@ -1529,17 +1529,16 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, plug = container_of(cb, struct raid1_plug_cb, cb); else plug = NULL; - spin_lock_irqsave(&conf->device_lock, flags); if (plug) { bio_list_add(&plug->pending, mbio); plug->pending_cnt++; } else { + spin_lock_irqsave(&conf->device_lock, flags); bio_list_add(&conf->pending_bio_list, mbio); conf->pending_count++; - } - spin_unlock_irqrestore(&conf->device_lock, flags); - if (!plug) + spin_unlock_irqrestore(&conf->device_lock, flags); md_wakeup_thread(mddev->thread); + } } r1_bio_write_done(r1_bio);diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 6b86a0032cf8..4343d7ff9916 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c@@ -1282,17 +1282,16 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, plug = container_of(cb, struct raid10_plug_cb, cb); else plug = NULL; - spin_lock_irqsave(&conf->device_lock, flags); if (plug) { bio_list_add(&plug->pending, mbio); plug->pending_cnt++; } else { + spin_lock_irqsave(&conf->device_lock, flags); bio_list_add(&conf->pending_bio_list, mbio); conf->pending_count++; - } - spin_unlock_irqrestore(&conf->device_lock, flags); - if (!plug) + spin_unlock_irqrestore(&conf->device_lock, flags); md_wakeup_thread(mddev->thread); + } } static void raid10_write_request(struct mddev *mddev, struct bio *bio,-- 2.11.0
Attachments
- signature.asc [application/pgp-signature] 832 bytes