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* [PATCH] ext4: make __ext4_get_inode_loc plug
@ 2019-06-17 15:57 jinshui zhang
  2019-06-19 11:08 ` Jan Kara
  2019-06-20  3:42 ` Theodore Ts'o
  0 siblings, 2 replies; 6+ messages in thread
From: jinshui zhang @ 2019-06-17 15:57 UTC (permalink / raw)
  To: tytso, adilger.kernel; +Cc: linux-ext4, linux-kernel, zhangjs

From: zhangjs <zachary@baishancloud.com>

If the task is unplugged when called, the inode_readahead_blks may not be merged, 
these will cause small pieces of io, It should be plugged.

Signed-off-by: zhangjs <zachary@baishancloud.com>
---
 fs/ext4/inode.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c7f77c6..8fe046b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4570,6 +4570,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 	struct buffer_head	*bh;
 	struct super_block	*sb = inode->i_sb;
 	ext4_fsblk_t		block;
+	struct blk_plug		plug;
 	int			inodes_per_block, inode_offset;
 
 	iloc->bh = NULL;
@@ -4654,6 +4655,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
 		}
 
 make_io:
+		blk_start_plug(&plug);
+
 		/*
 		 * If we need to do any I/O, try to pre-readahead extra
 		 * blocks from the inode table.
@@ -4688,6 +4691,9 @@ static int __ext4_get_inode_loc(struct inode *inode,
 		get_bh(bh);
 		bh->b_end_io = end_buffer_read_sync;
 		submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
+
+		blk_finish_plug(&plug);
+
 		wait_on_buffer(bh);
 		if (!buffer_uptodate(bh)) {
 			EXT4_ERROR_INODE_BLOCK(inode, block,
-- 
1.8.3.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ext4: make __ext4_get_inode_loc plug
  2019-06-17 15:57 [PATCH] ext4: make __ext4_get_inode_loc plug jinshui zhang
@ 2019-06-19 11:08 ` Jan Kara
       [not found]   ` <8BF438AD-0EA2-4F15-B565-A171E3AB13FA@gmail.com>
  2019-06-19 12:29   ` Zhangjs Jinshui
  2019-06-20  3:42 ` Theodore Ts'o
  1 sibling, 2 replies; 6+ messages in thread
From: Jan Kara @ 2019-06-19 11:08 UTC (permalink / raw)
  To: jinshui zhang; +Cc: tytso, adilger.kernel, linux-ext4, linux-kernel, zhangjs

On Mon 17-06-19 23:57:12, jinshui zhang wrote:
> From: zhangjs <zachary@baishancloud.com>
> 
> If the task is unplugged when called, the inode_readahead_blks may not be merged, 
> these will cause small pieces of io, It should be plugged.
> 
> Signed-off-by: zhangjs <zachary@baishancloud.com>

Out of curiosity, on which path do you see __ext4_get_inode_loc() being
called without IO already plugged?

Otherwise the patch looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/inode.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index c7f77c6..8fe046b 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4570,6 +4570,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
>  	struct buffer_head	*bh;
>  	struct super_block	*sb = inode->i_sb;
>  	ext4_fsblk_t		block;
> +	struct blk_plug		plug;
>  	int			inodes_per_block, inode_offset;
>  
>  	iloc->bh = NULL;
> @@ -4654,6 +4655,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
>  		}
>  
>  make_io:
> +		blk_start_plug(&plug);
> +
>  		/*
>  		 * If we need to do any I/O, try to pre-readahead extra
>  		 * blocks from the inode table.
> @@ -4688,6 +4691,9 @@ static int __ext4_get_inode_loc(struct inode *inode,
>  		get_bh(bh);
>  		bh->b_end_io = end_buffer_read_sync;
>  		submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
> +
> +		blk_finish_plug(&plug);
> +
>  		wait_on_buffer(bh);
>  		if (!buffer_uptodate(bh)) {
>  			EXT4_ERROR_INODE_BLOCK(inode, block,
> -- 
> 1.8.3.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ext4: make __ext4_get_inode_loc plug
       [not found]   ` <8BF438AD-0EA2-4F15-B565-A171E3AB13FA@gmail.com>
@ 2019-06-19 12:24     ` Jan Kara
  0 siblings, 0 replies; 6+ messages in thread
From: Jan Kara @ 2019-06-19 12:24 UTC (permalink / raw)
  To: Zhangjs Jinshui
  Cc: Jan Kara, Theodore Ts'o, adilger.kernel, linux-ext4,
	linux-kernel, zhangjs

On Wed 19-06-19 19:34:00, Zhangjs Jinshui wrote:
> You can blktrace
> 
>   8,80  31       11     0.296373038 2885275  Q  RA 8279571464 + 8 [xxxx]
>   8,80  31       12     0.296374017 2885275  G  RA 8279571464 + 8 [xxxx]
>   8,80  31       13     0.296375468 2885275  I  RA 8279571464 + 8 [xxxx]
>   8,80  31       14     0.296382099  3886  D  RA 8279571464 + 8 [kworker/31:1H]
>   8,80  31       15     0.296391907 2885275  Q  RA 8279571472 + 8 [xxxx]
>   8,80  31       16     0.296392275 2885275  G  RA 8279571472 + 8 [xxxx]
>   8,80  31       17     0.296393305 2885275  I  RA 8279571472 + 8 [xxxx]
>   8,80  31       18     0.296395844  3886  D  RA 8279571472 + 8 [kworker/31:1H]
>   8,80  31       19     0.296399685 2885275  Q  RA 8279571480 + 8 [xxxx]
>   8,80  31       20     0.296400025 2885275  G  RA 8279571480 + 8 [xxxx]
>   8,80  31       21     0.296401232 2885275  I  RA 8279571480 + 8 [xxxx]
>   8,80  31       22     0.296403422  3886  D  RA 8279571480 + 8 [kworker/31:1H]
>   8,80  31       23     0.296407375 2885275  Q  RA 8279571488 + 8 [xxxx]
>   8,80  31       24     0.296407721 2885275  G  RA 8279571488 + 8 [xxxx]
>   8,80  31       25     0.296408904 2885275  I  RA 8279571488 + 8 [xxxx]
>   8,80  31       26     0.296411127  3886  D  RA 8279571488 + 8 [kworker/31:1H]
>   8,80  31       27     0.296414779 2885275  Q  RA 8279571496 + 8 [xxxx]
>   8,80  31       28     0.296415119 2885275  G  RA 8279571496 + 8 [xxxx]
>   8,80  31       29     0.296415744 2885275  I  RA 8279571496 + 8 [xxxx]
>   8,80  31       30     0.296417779  3886  D  RA 8279571496 + 8 [kworker/31:1H]
> 
> these RA io were caused by ext4_inode_readahead_blks, there are all not merged becourse of the unplugged state.
> the backtrace shows below, was traced by systemtap ioblock.request filtered by "opf & 1 << 19"
> 
>  0xffffffff8136fb20 : generic_make_request+0x0/0x2f0 [kernel]
>  0xffffffff8136fe7e : submit_bio+0x6e/0x130 [kernel]
>  0xffffffff812971e6 : submit_bh_wbc+0x156/0x190 [kernel]
>  0xffffffff81297bca : ll_rw_block+0x6a/0xb0 [kernel]
>  0xffffffff81297cc0 : __breadahead+0x40/0x70 [kernel]
>  0xffffffffa0392c9a : __ext4_get_inode_loc+0x37a/0x3d0 [ext4]
>  0xffffffffa0396a6c : ext4_iget+0x8c/0xc00 [ext4]
>  0xffffffffa03ad98a : ext4_lookup+0xca/0x1d0 [ext4]
>  0xffffffff8126b814 : path_openat+0xcb4/0x1250 [kernel]
>  0xffffffff8126dc41 : do_filp_open+0x91/0x100 [kernel]
>  0xffffffff8125ad86 : do_sys_open+0x126/0x210 [kernel]
>  0xffffffff81003864 : do_syscall_64+0x74/0x1a0 [kernel]
>  0xffffffff81800081 : entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [kernel]
> 
> I have patched it on online servers, It can improved the performance.

Ah, OK, directory lookup code... Makes sense. Thanks for sharing!

								Honza

> 
> > 在 2019年6月19日,19:08,Jan Kara <jack@suse.cz> 写道:
> > 
> > On Mon 17-06-19 23:57:12, jinshui zhang wrote:
> >> From: zhangjs <zachary@baishancloud.com <mailto:zachary@baishancloud.com>>
> >> 
> >> If the task is unplugged when called, the inode_readahead_blks may not be merged, 
> >> these will cause small pieces of io, It should be plugged.
> >> 
> >> Signed-off-by: zhangjs <zachary@baishancloud.com <mailto:zachary@baishancloud.com>>
> > 
> > Out of curiosity, on which path do you see __ext4_get_inode_loc() being
> > called without IO already plugged?
> > 
> > Otherwise the patch looks good to me. You can add:
> > 
> > Reviewed-by: Jan Kara <jack@suse.cz <mailto:jack@suse.cz>>
> > 
> > 								Honza
> > 
> >> ---
> >> fs/ext4/inode.c | 6 ++++++
> >> 1 file changed, 6 insertions(+)
> >> 
> >> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> >> index c7f77c6..8fe046b 100644
> >> --- a/fs/ext4/inode.c
> >> +++ b/fs/ext4/inode.c
> >> @@ -4570,6 +4570,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
> >> 	struct buffer_head	*bh;
> >> 	struct super_block	*sb = inode->i_sb;
> >> 	ext4_fsblk_t		block;
> >> +	struct blk_plug		plug;
> >> 	int			inodes_per_block, inode_offset;
> >> 
> >> 	iloc->bh = NULL;
> >> @@ -4654,6 +4655,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
> >> 		}
> >> 
> >> make_io:
> >> +		blk_start_plug(&plug);
> >> +
> >> 		/*
> >> 		 * If we need to do any I/O, try to pre-readahead extra
> >> 		 * blocks from the inode table.
> >> @@ -4688,6 +4691,9 @@ static int __ext4_get_inode_loc(struct inode *inode,
> >> 		get_bh(bh);
> >> 		bh->b_end_io = end_buffer_read_sync;
> >> 		submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
> >> +
> >> +		blk_finish_plug(&plug);
> >> +
> >> 		wait_on_buffer(bh);
> >> 		if (!buffer_uptodate(bh)) {
> >> 			EXT4_ERROR_INODE_BLOCK(inode, block,
> >> -- 
> >> 1.8.3.1
> >> 
> > -- 
> > Jan Kara <jack@suse.com <mailto:jack@suse.com>>
> > SUSE Labs, CR
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ext4: make __ext4_get_inode_loc plug
  2019-06-19 11:08 ` Jan Kara
       [not found]   ` <8BF438AD-0EA2-4F15-B565-A171E3AB13FA@gmail.com>
@ 2019-06-19 12:29   ` Zhangjs Jinshui
  1 sibling, 0 replies; 6+ messages in thread
From: Zhangjs Jinshui @ 2019-06-19 12:29 UTC (permalink / raw)
  To: linux-ext4, linux-kernel


> 在 2019年6月19日,19:08,Jan Kara <jack@suse.cz> 写道:
> 
> On Mon 17-06-19 23:57:12, jinshui zhang wrote:
>> From: zhangjs <zachary@baishancloud.com>
>> 
>> If the task is unplugged when called, the inode_readahead_blks may not be merged, 
>> these will cause small pieces of io, It should be plugged.
>> 
>> Signed-off-by: zhangjs <zachary@baishancloud.com>
> 
> Out of curiosity, on which path do you see __ext4_get_inode_loc() being
> called without IO already plugged?
> 
> Otherwise the patch looks good to me. You can add:
> 
> Reviewed-by: Jan Kara <jack@suse.cz>
> 
> 								Honza
> 
>> ---
>> fs/ext4/inode.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>> 
>> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
>> index c7f77c6..8fe046b 100644
>> --- a/fs/ext4/inode.c
>> +++ b/fs/ext4/inode.c
>> @@ -4570,6 +4570,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
>> 	struct buffer_head	*bh;
>> 	struct super_block	*sb = inode->i_sb;
>> 	ext4_fsblk_t		block;
>> +	struct blk_plug		plug;
>> 	int			inodes_per_block, inode_offset;
>> 
>> 	iloc->bh = NULL;
>> @@ -4654,6 +4655,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
>> 		}
>> 
>> make_io:
>> +		blk_start_plug(&plug);
>> +
>> 		/*
>> 		 * If we need to do any I/O, try to pre-readahead extra
>> 		 * blocks from the inode table.
>> @@ -4688,6 +4691,9 @@ static int __ext4_get_inode_loc(struct inode *inode,
>> 		get_bh(bh);
>> 		bh->b_end_io = end_buffer_read_sync;
>> 		submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
>> +
>> +		blk_finish_plug(&plug);
>> +
>> 		wait_on_buffer(bh);
>> 		if (!buffer_uptodate(bh)) {
>> 			EXT4_ERROR_INODE_BLOCK(inode, block,
>> -- 
>> 1.8.3.1
>> 
> -- 
> Jan Kara <jack@suse.com>
> SUSE Labs, CR

You can blktrace

  8,80  31       11     0.296373038 2885275  Q  RA 8279571464 + 8 [xxxx]
  8,80  31       12     0.296374017 2885275  G  RA 8279571464 + 8 [xxxx]
  8,80  31       13     0.296375468 2885275  I  RA 8279571464 + 8 [xxxx]
  8,80  31       14     0.296382099  3886  D  RA 8279571464 + 8 [kworker/31:1H]
  8,80  31       15     0.296391907 2885275  Q  RA 8279571472 + 8 [xxxx]
  8,80  31       16     0.296392275 2885275  G  RA 8279571472 + 8 [xxxx]
  8,80  31       17     0.296393305 2885275  I  RA 8279571472 + 8 [xxxx]
  8,80  31       18     0.296395844  3886  D  RA 8279571472 + 8 [kworker/31:1H]
  8,80  31       19     0.296399685 2885275  Q  RA 8279571480 + 8 [xxxx]
  8,80  31       20     0.296400025 2885275  G  RA 8279571480 + 8 [xxxx]
  8,80  31       21     0.296401232 2885275  I  RA 8279571480 + 8 [xxxx]
  8,80  31       22     0.296403422  3886  D  RA 8279571480 + 8 [kworker/31:1H]
  8,80  31       23     0.296407375 2885275  Q  RA 8279571488 + 8 [xxxx]
  8,80  31       24     0.296407721 2885275  G  RA 8279571488 + 8 [xxxx]
  8,80  31       25     0.296408904 2885275  I  RA 8279571488 + 8 [xxxx]
  8,80  31       26     0.296411127  3886  D  RA 8279571488 + 8 [kworker/31:1H]
  8,80  31       27     0.296414779 2885275  Q  RA 8279571496 + 8 [xxxx]
  8,80  31       28     0.296415119 2885275  G  RA 8279571496 + 8 [xxxx]
  8,80  31       29     0.296415744 2885275  I  RA 8279571496 + 8 [xxxx]
  8,80  31       30     0.296417779  3886  D  RA 8279571496 + 8 [kworker/31:1H]

these RA io were caused by ext4_inode_readahead_blks, there are all not merged becourse of the unplugged state.
the backtrace shows below, was traced by systemtap ioblock.request filtered by "opf & 1 << 19"

 0xffffffff8136fb20 : generic_make_request+0x0/0x2f0 [kernel]
 0xffffffff8136fe7e : submit_bio+0x6e/0x130 [kernel]
 0xffffffff812971e6 : submit_bh_wbc+0x156/0x190 [kernel]
 0xffffffff81297bca : ll_rw_block+0x6a/0xb0 [kernel]
 0xffffffff81297cc0 : __breadahead+0x40/0x70 [kernel]
 0xffffffffa0392c9a : __ext4_get_inode_loc+0x37a/0x3d0 [ext4]
 0xffffffffa0396a6c : ext4_iget+0x8c/0xc00 [ext4]
 0xffffffffa03ad98a : ext4_lookup+0xca/0x1d0 [ext4]
 0xffffffff8126b814 : path_openat+0xcb4/0x1250 [kernel]
 0xffffffff8126dc41 : do_filp_open+0x91/0x100 [kernel]
 0xffffffff8125ad86 : do_sys_open+0x126/0x210 [kernel]
 0xffffffff81003864 : do_syscall_64+0x74/0x1a0 [kernel]
 0xffffffff81800081 : entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [kernel]

I have patched it on online servers, It can improved the performance.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ext4: make __ext4_get_inode_loc plug
  2019-06-17 15:57 [PATCH] ext4: make __ext4_get_inode_loc plug jinshui zhang
  2019-06-19 11:08 ` Jan Kara
@ 2019-06-20  3:42 ` Theodore Ts'o
  1 sibling, 0 replies; 6+ messages in thread
From: Theodore Ts'o @ 2019-06-20  3:42 UTC (permalink / raw)
  To: jinshui zhang; +Cc: adilger.kernel, linux-ext4, linux-kernel, zhangjs

On Mon, Jun 17, 2019 at 11:57:12PM +0800, jinshui zhang wrote:
> From: zhangjs <zachary@baishancloud.com>
> 
> If the task is unplugged when called, the inode_readahead_blks may not be merged, 
> these will cause small pieces of io, It should be plugged.
> 
> Signed-off-by: zhangjs <zachary@baishancloud.com>

Thanks, applied.

I cleaned up the commit description a little, and I removed some of
the extra empty lines added by the patch.

Cheers,

					- Ted

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ext4: make __ext4_get_inode_loc plug
       [not found] <CAEKGrW601HBKVA+FsoeCPMXFZnzv8r0_96FaLDnVKCp=KmcvtA@mail.gmail.com>
@ 2019-06-17 14:09 ` Theodore Ts'o
  0 siblings, 0 replies; 6+ messages in thread
From: Theodore Ts'o @ 2019-06-17 14:09 UTC (permalink / raw)
  To: Zhangjs Jinshui; +Cc: adilger.kernel, linux-ext4, linux-kernel, zachary

On Mon, Jun 17, 2019 at 03:11:21PM +0800, Zhangjs Jinshui wrote:
> If the task is unplugged when called, the inode_readahead_blks may not be
> merged,
> these will cause small pieces of io, It should be plugged.
> 
> Signed-off-by: zhangjs <zachary@baishancloud.com>

This patch is white space damaged.   Please see:

https://www.kernel.org/doc/html/latest/process/email-clients.html

for more information.  Could you resend using an appropriate mail
client?

Many thanks!

					- Ted

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-06-20  4:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-06-17 15:57 [PATCH] ext4: make __ext4_get_inode_loc plug jinshui zhang
2019-06-19 11:08 ` Jan Kara
     [not found]   ` <8BF438AD-0EA2-4F15-B565-A171E3AB13FA@gmail.com>
2019-06-19 12:24     ` Jan Kara
2019-06-19 12:29   ` Zhangjs Jinshui
2019-06-20  3:42 ` Theodore Ts'o
     [not found] <CAEKGrW601HBKVA+FsoeCPMXFZnzv8r0_96FaLDnVKCp=KmcvtA@mail.gmail.com>
2019-06-17 14:09 ` Theodore Ts'o

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