[Ocfs2-devel] [PATCH v2] ocfs2: improve recovery performance

[Junxiao Bi <junxiao.bi@oracle.com>]

On 07/09/2016 05:23 AM, Andrew Morton wrote:
> On Thu,  7 Jul 2016 10:24:48 +0800 Junxiao Bi <junxiao.bi@oracle.com> wrote:
> 
>> Journal replay will be run when do recovery for a dead node,
>> to avoid the stale cache impact, all blocks of dead node's
>> journal inode were reload from disk. This hurts the performance,
>> check whether one block is cached before reload it can improve
>> a lot performance. In my test env, the time doing recovery was
>> improved from 120s to 1s.
> 
> So since v1 you did this (unchangelogged bugfix!):
> 
> --- a/fs/ocfs2/journal.c~ocfs2-improve-recovery-performance-v2
> +++ a/fs/ocfs2/journal.c
> @@ -1194,6 +1194,7 @@ static int ocfs2_force_read_journal(stru
>  
>  			brelse(bh);
>  			bh = NULL;
> +			p_blkno++;
>  		}
>  
>  		v_blkno += p_blocks;
> 
> 
> I suppose this is a bit neater?
Yes, looks good. Thank you.

Thanks,
Junxiao.
> 
> --- a/fs/ocfs2/journal.c~ocfs2-improve-recovery-performance-v2-fix
> +++ a/fs/ocfs2/journal.c
> @@ -1172,14 +1172,12 @@ static int ocfs2_force_read_journal(stru
>  			goto bail;
>  		}
>  
> -		for (i = 0; i < p_blocks; i++) {
> +		for (i = 0; i < p_blocks; i++, p_blkno++) {
>  			bh = __find_get_block(osb->sb->s_bdev, p_blkno,
>  					osb->sb->s_blocksize);
>  			/* block not cached. */
> -			if (!bh) {
> -				p_blkno++;
> +			if (!bh)
>  				continue;
> -			}
>  
>  			brelse(bh);
>  			bh = NULL;
> @@ -1194,7 +1192,6 @@ static int ocfs2_force_read_journal(stru
>  
>  			brelse(bh);
>  			bh = NULL;
> -			p_blkno++;
>  		}
>  
>  		v_blkno += p_blocks;
> _
>