[PATCH v2] f2fs: remove nested usage of plug list

[PATCH v2] f2fs: remove nested usage of plug list

[Yunlei He]

-f2fs_file_write_iter
  -blk_start_plug
    -__generic_file_write_iter
	...
	  -do_blockdev_direct_IO
	    -blk_start_plug
		...
	    -blk_finish_plug
	...
  -blk_finish_plug

which may conduct performance decrease in our platform

Signed-off-by: Yunlei He <heyunlei@huawei.com>
---
 fs/f2fs/file.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 6b94f19..977c800 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2894,7 +2894,6 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file_inode(file);
-	struct blk_plug plug;
 	ssize_t ret;
 
 	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
@@ -2939,9 +2938,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 				return err;
 			}
 		}
-		blk_start_plug(&plug);
 		ret = __generic_file_write_iter(iocb, from);
-		blk_finish_plug(&plug);
 		clear_inode_flag(inode, FI_NO_PREALLOC);
 
 		/* if we couldn't write data, we should deallocate blocks. */
-- 
1.9.1


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Re: [PATCH v2] f2fs: remove nested usage of plug list

[Chao Yu]

On 2018/4/8 10:59, Yunlei He wrote:
> -f2fs_file_write_iter
>   -blk_start_plug
>     -__generic_file_write_iter
> 	...
> 	  -do_blockdev_direct_IO
> 	    -blk_start_plug
> 		...
> 	    -blk_finish_plug
> 	...
>   -blk_finish_plug
> 
> which may conduct performance decrease in our platform

Have sent this before, let me integrate your description into mine and add
signed-off, anyway, well cleanup job! ;)

Thanks,

> 
> Signed-off-by: Yunlei He <heyunlei@huawei.com>
> ---
>  fs/f2fs/file.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 6b94f19..977c800 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2894,7 +2894,6 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  {
>  	struct file *file = iocb->ki_filp;
>  	struct inode *inode = file_inode(file);
> -	struct blk_plug plug;
>  	ssize_t ret;
>  
>  	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
> @@ -2939,9 +2938,7 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
>  				return err;
>  			}
>  		}
> -		blk_start_plug(&plug);
>  		ret = __generic_file_write_iter(iocb, from);
> -		blk_finish_plug(&plug);
>  		clear_inode_flag(inode, FI_NO_PREALLOC);
>  
>  		/* if we couldn't write data, we should deallocate blocks. */
> 


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