From: Dave Chinner <david@fromorbit.com>
To: kernel test robot <xiaolong.ye@intel.com>
Cc: Dave Chinner <dchinner@redhat.com>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
Christoph Hellwig <hch@lst.de>,
Carlos Maiolino <cmaiolino@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-xfs@vger.kernel.org, lkp@01.org
Subject: Re: [lkp-robot] [xfs] b027d4c97b: fio.latency_2ms% +7.1% regression
Date: Wed, 6 Jun 2018 08:38:13 +1000 [thread overview]
Message-ID: <20180605223813.GI10363@dastard> (raw)
In-Reply-To: <20180605071657.GP16472@yexl-desktop>
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.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2018-06-05 22:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-05 7:16 [lkp-robot] [xfs] b027d4c97b: fio.latency_2ms% +7.1% regression kernel test robot
2018-06-05 22:38 ` Dave Chinner [this message]
2018-06-06 1:40 ` Ye Xiaolong
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