From: Xing Zhengjun <zhengjun.xing@linux.intel.com>
To: dsterba@suse.cz, "kernel test robot" <oliver.sang@intel.com>,
"Josef Bacik" <josef@toxicpanda.com>,
"David Sterba" <dsterba@suse.com>,
"René Rebe" <rene@exactcode.de>,
LKML <linux-kernel@vger.kernel.org>,
lkp@lists.01.org, lkp@intel.com, ying.huang@intel.com,
feng.tang@intel.com, linux-btrfs@vger.kernel.org
Subject: Re: [LKP] Re: [btrfs] e076ab2a2c: fio.write_iops -18.3% regression
Date: Wed, 13 Jan 2021 13:58:18 +0800 [thread overview]
Message-ID: <979aee28-c603-a187-e03f-29957c7b94d6@linux.intel.com> (raw)
In-Reply-To: <20210112154529.GT6430@twin.jikos.cz>
On 1/12/2021 11:45 PM, David Sterba wrote:
> On Tue, Jan 12, 2021 at 11:36:14PM +0800, kernel test robot wrote:
>> Greeting,
>>
>> FYI, we noticed a -18.3% regression of fio.write_iops due to commit:
>>
>>
>> commit: e076ab2a2ca70a0270232067cd49f76cd92efe64 ("btrfs: shrink delalloc pages instead of full inodes")
>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>>
>>
>> in testcase: fio-basic
>> on test machine: 192 threads Intel(R) Xeon(R) CPU @ 2.20GHz with 192G memory
>> with following parameters:
>>
>> disk: 1SSD
>> fs: btrfs
>> runtime: 300s
>> nr_task: 8
>> rw: randwrite
>> bs: 4k
>> ioengine: sync
>> test_size: 256g
> Though I do a similar test (emulating bit torrent workload), it's a bit
> extreme as it's 4k synchronous on a huge file. It always takes a lot of
> time but could point out some concurrency issues namely on faster
> devices. There are 8 threads possibly competing for the same inode lock
> or other locks related to it.
>
> The mentioned commit fixed another perf regression on a much more common
> workload (untgrring files), so at this point drop in this fio workload
> is inevitable.
Do you have a plan to fix it? Thanks.
> _______________________________________________
> LKP mailing list -- lkp@lists.01.org
> To unsubscribe send an email to lkp-leave@lists.01.org
--
Zhengjun Xing
next prev parent reply other threads:[~2021-01-13 6:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 15:36 [btrfs] e076ab2a2c: fio.write_iops -18.3% regression kernel test robot
2021-01-12 15:45 ` David Sterba
2021-01-13 5:58 ` Xing Zhengjun [this message]
2021-01-14 22:50 ` [LKP] " David Sterba
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=979aee28-c603-a187-e03f-29957c7b94d6@linux.intel.com \
--to=zhengjun.xing@linux.intel.com \
--cc=dsterba@suse.com \
--cc=dsterba@suse.cz \
--cc=feng.tang@intel.com \
--cc=josef@toxicpanda.com \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@intel.com \
--cc=lkp@lists.01.org \
--cc=oliver.sang@intel.com \
--cc=rene@exactcode.de \
--cc=ying.huang@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).