On 06/06, Dave Chinner wrote:
>On Tue, Jun 05, 2018 at 03:16:57PM +0800, kernel test robot wrote:
>>
>> Greeting,
>>
>> FYI, we noticed a +7.1%% regression of fio.latency_2ms% due to commit:
>>
>>
>> commit: b027d4c97b9675c2ad75dec94be4e46dceb3ec74 ("xfs: don't retry
>> xfs_buf_find on XBF_TRYLOCK failure")
>> https://git.kernel.org/cgit/fs/xfs/xfs-linux.git xfs-4.18-merge
>....
>> 8925a3dc4771004b b027d4c97b9675c2ad75dec94b
>> ---------------- --------------------------
>> %stddev %change %stddev
>> \ | \
>> 46.56 ± 3% +7.1 53.61 fio.latency_2ms%
>> 8.19 +0.2 8.40 fio.latency_100ms%
>> 0.74 ± 3% -0.1 0.68 ± 6% fio.latency_250ms%
>> 25.20 ± 6% -7.3 17.86 ± 6% fio.latency_4ms%
>> 0.46 ± 9% +0.2 0.69 ± 13% fio.latency_750us%
>
>This is not a regression. The number of IOs in the 4ms IO latency
>bin has reduced by 7%, and inumber in the 2ms IO latency bin has
>increased by 7%. IOWs, there's a measurable improvement in IO
>latency as a result of those patches, not a regression.
Thanks for clarification.
Thanks,
Xiaolong
>
>Cheers,
>
>Dave.
>--
>Dave Chinner
>da...@fromorbit.com
