Re: [PATCH V3] xfs: use roundup_pow_of_two instead of ffs during xlog_find_tail

From: Chandan Babu R
Date: Tue Sep 19 2023 - 02:37:05 EST


On Mon, Sep 18, 2023 at 08:21:38 PM -0700, Darrick J. Wong wrote:
> On Tue, Sep 19, 2023 at 10:06:56AM +0800, Wang Jianchao wrote:
>> Ping ? Do I need other update on this patch ?
>
> Nope, I think this is ok...
>
>> Thanks
>> Jianchao
>>
>> On 2023/9/13 09:38, Wang Jianchao wrote:
>> >
>> > In our production environment, we find that mounting a 500M /boot
>> > which is umount cleanly needs ~6s. One cause is that ffs() is
>> > used by xlog_write_log_records() to decide the buffer size. It
>> > can cause a lot of small IO easily when xlog_clear_stale_blocks()
>> > needs to wrap around the end of log area and log head block is
>> > not power of two. Things are similar in xlog_find_verify_cycle().
>> >
>> > The code is able to handed bigger buffer very well, we can use
>> > roundup_pow_of_two() to replace ffs() directly to avoid small
>> > and sychronous IOs.
>> >
>> > Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
>> > Signed-off-by: Wang Jianchao <wangjc136@xxxxxxxxx>
>
> ...so let's see if the release manager will take this patch.
>
> Chandan? Could you pull in the various one-off patches floating around
> on the list that have passed review? ;)

I had picked this patch along with others sometime last week.

I have pushed the new set of commits to official xfs-linux git repository and
sent the announcement mail around 30 mins ago.

>
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> PS: If you'd like to send a pull request to push things along, please do
>

--
Chandan