fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices

PATCH In review majianpeng 3 participants 5 messages Jul 16, 2012 – Aug 2, 2012

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VFS MD RAID

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majianpeng

author

2012-07-16 06:21 UTC #0 lore raw

PATCH 1/2 fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices

For regular file, write operaion used blk_plug function.But for block file,write operation did not use blk_plug.
This patch is also for write-cache mode for block-device.

Signed-off-by Jianpeng Ma <[email protected]>

---
 fs/block_dev.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

fs/block_dev.c +3 -0

index c2bbe1f..cf10778 100644
@@ -1579,9 +1579,11 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t ret;
+	struct blk_plug plug;
 
 	BUG_ON(iocb->ki_pos != pos);
 
+	blk_start_plug(&plug);
 	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
 	if (ret > 0 || ret == -EIOCBQUEUED) {
 		ssize_t err;

@@ -1590,6 +1592,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		if (err < 0 && ret > 0)
 			ret = err;
 	}
+	blk_finish_plug(&plug);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blkdev_aio_write);

Signature · 1 line

1.7.5.4

NeilBrown

Reviewed-by on v1 1/2

2012-07-17 03:04 UTC #1 lore raw

Quoted 5 lines · On Mon, 16 Jul 2012 14:22:03 +0800 majianpeng <[email protected]> wrote:

For regular file, write operaion used blk_plug function.But for block file,write operation did not use blk_plug.
This patch is also for write-cache mode for block-device.
Signed-off-by Jianpeng Ma <[email protected]>

Reviewed-by NeilBrown <[email protected]>

Will you take this Jens? Though mail to you seem to be bouncing:

<[email protected]>: host mail.fusionio.com[10.101.1.19] said: 554 5.4.6 Hop
count exceeded - possible mail loop (in reply to end of DATA command)

so I'm not sure you'll even see this :-(

NeilBrown

Quoted 28 lines

---
 fs/block_dev.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

fs/block_dev.c +3 -0

index c2bbe1f..cf10778 100644
@@ -1579,9 +1579,11 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t ret;
+	struct blk_plug plug;
 
 	BUG_ON(iocb->ki_pos != pos);
 
+	blk_start_plug(&plug);
 	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
 	if (ret > 0 || ret == -EIOCBQUEUED) {
 		ssize_t err;

@@ -1590,6 +1592,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		if (err < 0 && ret > 0)
 			ret = err;
 	}
+	blk_finish_plug(&plug);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blkdev_aio_write);

majianpeng

author

2012-07-17 05:07 UTC #2 lore raw

On 2012-07-17 11:04 NeilBrown <[email protected]> Wrote:

Quoted 8 lines · On Mon, 16 Jul 2012 14:22:03 +0800 majianpeng <[email protected]> wrote:

Quoted 6 lines
For regular file, write operaion used blk_plug function.But for block file,write operation did not use blk_plug.
This patch is also for write-cache mode for block-device.
Signed-off-by Jianpeng Ma <[email protected]>

Quoted 9 lines

Reviewed-by NeilBrown <[email protected]>
Will you take this Jens? Though mail to you seem to be bouncing:
<[email protected]>: host mail.fusionio.com[10.101.1.19] said: 554 5.4.6 Hop
count exceeded - possible mail loop (in reply to end of DATA command)
so I'm not sure you'll even see this :-(

I see it.

Quoted 32 lines

NeilBrown

Quoted 28 lines

---
 fs/block_dev.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

fs/block_dev.c +3 -0

index c2bbe1f..cf10778 100644
@@ -1579,9 +1579,11 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t ret;
+	struct blk_plug plug;
 
 	BUG_ON(iocb->ki_pos != pos);
 
+	blk_start_plug(&plug);
 	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
 	if (ret > 0 || ret == -EIOCBQUEUED) {
 		ssize_t err;

@@ -1590,6 +1592,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		if (err < 0 && ret > 0)
 			ret = err;
 	}
+	blk_finish_plug(&plug);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blkdev_aio_write);

majianpeng

author

2012-08-02 06:48 UTC #3 lore raw

In reply to NeilBrown

On 2012-07-17 11:04 NeilBrown <[email protected]> Wrote:

Quoted 35 lines · On Mon, 16 Jul 2012 14:22:03 +0800 majianpeng <[email protected]> wrote:

Quoted 6 lines
For regular file, write operaion used blk_plug function.But for block file,write operation did not use blk_plug.
This patch is also for write-cache mode for block-device.
Signed-off-by Jianpeng Ma <[email protected]>
Reviewed-by NeilBrown <[email protected]>
Will you take this Jens? Though mail to you seem to be bouncing:
<[email protected]>: host mail.fusionio.com[10.101.1.19] said: 554 5.4.6 Hop
count exceeded - possible mail loop (in reply to end of DATA command)
so I'm not sure you'll even see this :-(
NeilBrown
Quoted 16 lines
---
 fs/block_dev.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
fs/block_dev.c +1 -0
index c2bbe1f..cf10778 100644
@@ -1579,9 +1579,11 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t ret;
+	struct blk_plug plug;
 
 	BUG_ON(iocb->ki_pos != pos);
 

Quoted 14 lines

fs/block_dev.c ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, · line 1598

Quoted 12 lines

fs/block_dev.c +2 -0

+	blk_start_plug(&plug);
 	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
 	if (ret > 0 || ret == -EIOCBQUEUED) {
 		ssize_t err;

@@ -1590,6 +1592,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		if (err < 0 && ret > 0)
 			ret = err;
 	}
+	blk_finish_plug(&plug);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blkdev_aio_write);

How about this patch? apply or reject? Thanks!

Jens Axboe

2012-08-02 07:51 UTC #4 lore raw

Quoted 51 lines · majianpeng

On 2012-07-17 11:04 NeilBrown <[email protected]> Wrote:
Quoted 35 lines · On Mon, 16 Jul 2012 14:22:03 +0800 majianpeng <[email protected]> wrote:
Quoted 6 lines
For regular file, write operaion used blk_plug function.But for block file,write operation did not use blk_plug.
This patch is also for write-cache mode for block-device.
Signed-off-by Jianpeng Ma <[email protected]>
Reviewed-by NeilBrown <[email protected]>
Will you take this Jens? Though mail to you seem to be bouncing:
<[email protected]>: host mail.fusionio.com[10.101.1.19] said: 554 5.4.6 Hop
count exceeded - possible mail loop (in reply to end of DATA command)
so I'm not sure you'll even see this :-(
NeilBrown
Quoted 16 lines
---
 fs/block_dev.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
fs/block_dev.c +1 -0
index c2bbe1f..cf10778 100644
@@ -1579,9 +1579,11 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t ret;
+	struct blk_plug plug;
 
 	BUG_ON(iocb->ki_pos != pos);
 
Quoted 14 lines
fs/block_dev.c ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, · line 1598
Quoted 12 lines
fs/block_dev.c +2 -0
+	blk_start_plug(&plug);
 	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
 	if (ret > 0 || ret == -EIOCBQUEUED) {
 		ssize_t err;
@@ -1590,6 +1592,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		if (err < 0 && ret > 0)
 			ret = err;
 	}
+	blk_finish_plug(&plug);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(blkdev_aio_write);

Quoted 1 line

How about this patch? apply or reject? Thanks!

I've applied it for a bit of testing, then it'll got into 3.6. Thanks.

Signature · 1 line

Jens Axboe