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

[Junxiao Bi]

On 06/17/2016 04:32 PM, Joseph Qi wrote:
> On 2016/6/17 15:50, Junxiao Bi wrote:
>> Hi Joseph,
>>
>> On 06/17/2016 03:44 PM, Joseph Qi wrote:
>>> Hi Junxiao,
>>>
>>> On 2016/6/17 14:10, Junxiao Bi 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.
>>>>
>>>> Signed-off-by: Junxiao Bi <junxiao.bi at oracle.com>
>>>> ---
>>>>  fs/ocfs2/journal.c |   41 ++++++++++++++++++++++-------------------
>>>>  1 file changed, 22 insertions(+), 19 deletions(-)
>>>>
>>>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>>>> index e607419cdfa4..8b808afd5f82 100644
>>>> --- a/fs/ocfs2/journal.c
>>>> +++ b/fs/ocfs2/journal.c
>>>> @@ -1159,10 +1159,8 @@ static int ocfs2_force_read_journal(struct inode *inode)
>>>>  	int status = 0;
>>>>  	int i;
>>>>  	u64 v_blkno, p_blkno, p_blocks, num_blocks;
>>>> -#define CONCURRENT_JOURNAL_FILL 32ULL
>>>> -	struct buffer_head *bhs[CONCURRENT_JOURNAL_FILL];
>>>> -
>>>> -	memset(bhs, 0, sizeof(struct buffer_head *) * CONCURRENT_JOURNAL_FILL);
>>>> +	struct buffer_head *bhs[1] = {NULL};
>>> Since now we do not need batch load, how about make the logic like:
>>>
>>> 	struct buffer_head *bh = NULL;
>>> 	...
>>> 	ocfs2_read_blocks_sync(osb, p_blkno, 1, &bh);
>> This array is used because ocfs2_read_blocks_sync() needs it as last
>> parameter.
> IC, so we pass &bh like ocfs2_read_locked_inode.
Right, will submit v2.

Thanks,
Junxiao.
> 
> Thanks,
> Joseph
> 
>>
>> Thanks,
>> Junxiao.
>>>
>>> Thanks,
>>> Joseph
>>>
>>>> +	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>>>  
>>>>  	num_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
>>>>  	v_blkno = 0;
>>>> @@ -1174,29 +1172,34 @@ static int ocfs2_force_read_journal(struct inode *inode)
>>>>  			goto bail;
>>>>  		}
>>>>  
>>>> -		if (p_blocks > CONCURRENT_JOURNAL_FILL)
>>>> -			p_blocks = CONCURRENT_JOURNAL_FILL;
>>>> +		for (i = 0; i < p_blocks; i++) {
>>>> +			bhs[0] = __find_get_block(osb->sb->s_bdev, p_blkno,
>>>> +					osb->sb->s_blocksize);
>>>> +			/* block not cached. */
>>>> +			if (!bhs[0]) {
>>>> +				p_blkno++;
>>>> +				continue;
>>>> +			}
>>>>  
>>>> -		/* We are reading journal data which should not
>>>> -		 * be put in the uptodate cache */
>>>> -		status = ocfs2_read_blocks_sync(OCFS2_SB(inode->i_sb),
>>>> -						p_blkno, p_blocks, bhs);
>>>> -		if (status < 0) {
>>>> -			mlog_errno(status);
>>>> -			goto bail;
>>>> -		}
>>>> +			brelse(bhs[0]);
>>>> +			bhs[0] = NULL;
>>>> +			/* We are reading journal data which should not
>>>> +			 * be put in the uptodate cache.
>>>> +			 */
>>>> +			status = ocfs2_read_blocks_sync(osb, p_blkno, 1, bhs);
>>>> +			if (status < 0) {
>>>> +				mlog_errno(status);
>>>> +				goto bail;
>>>> +			}
>>>>  
>>>> -		for(i = 0; i < p_blocks; i++) {
>>>> -			brelse(bhs[i]);
>>>> -			bhs[i] = NULL;
>>>> +			brelse(bhs[0]);
>>>> +			bhs[0] = NULL;
>>>>  		}
>>>>  
>>>>  		v_blkno += p_blocks;
>>>>  	}
>>>>  
>>>>  bail:
>>>> -	for(i = 0; i < CONCURRENT_JOURNAL_FILL; i++)
>>>> -		brelse(bhs[i]);
>>>>  	return status;
>>>>  }
>>>>  
>>>>
>>>
>>>
>>
>>
>> .
>>
> 
>