All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Sterba <dsterba@suse.cz>
To: Qu Wenruo <wqu@suse.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>,
	kernel test robot <rong.a.chen@intel.com>,
	David Sterba <dsterba@suse.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Leonard Lausen <leonard@lausen.nl>,
	LKML <linux-kernel@vger.kernel.org>,
	lkp@01.org
Subject: Re: [LKP] [btrfs] 8d47a0d8f7: fio.write_bw_MBps -28.6% regression
Date: Fri, 10 Apr 2020 12:14:06 +0200	[thread overview]
Message-ID: <20200410101406.GI5920@suse.cz> (raw)
In-Reply-To: <a52f10f7-cdf6-9b00-9e49-b1344c17a190@suse.com>

On Fri, Apr 10, 2020 at 02:44:55PM +0800, Qu Wenruo wrote:
> On 2020/4/10 下午2:34, Xing Zhengjun wrote:
> > Hi Wenruo,
> > 
> >    We test it in v5.6, the issue still exist, do you have time to take a
> > look at this? Thanks.
> 
> This is expected.
> 
> The extra check brings new overhead mostly equal to another CRC32 run.
> 
> We believe it's worthy, as our read time tree checker has exposed quite
> some bit flip corruption.

The test probably runs on a PMEM device so there's no slowdown from the
actual IO and the in-memory checks are measurable, though 28% is a lot,
I'd expect something like 5-10% at most.

WARNING: multiple messages have this Message-ID (diff)
From: David Sterba <dsterba@suse.cz>
To: lkp@lists.01.org
Subject: Re: [btrfs] 8d47a0d8f7: fio.write_bw_MBps -28.6% regression
Date: Fri, 10 Apr 2020 12:14:06 +0200	[thread overview]
Message-ID: <20200410101406.GI5920@suse.cz> (raw)
In-Reply-To: <a52f10f7-cdf6-9b00-9e49-b1344c17a190@suse.com>

[-- Attachment #1: Type: text/plain, Size: 637 bytes --]

On Fri, Apr 10, 2020 at 02:44:55PM +0800, Qu Wenruo wrote:
> On 2020/4/10 下午2:34, Xing Zhengjun wrote:
> > Hi Wenruo,
> > 
> >    We test it in v5.6, the issue still exist, do you have time to take a
> > look at this? Thanks.
> 
> This is expected.
> 
> The extra check brings new overhead mostly equal to another CRC32 run.
> 
> We believe it's worthy, as our read time tree checker has exposed quite
> some bit flip corruption.

The test probably runs on a PMEM device so there's no slowdown from the
actual IO and the in-memory checks are measurable, though 28% is a lot,
I'd expect something like 5-10% at most.

  reply	other threads:[~2020-04-10 10:14 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-13  3:17 [btrfs] 8d47a0d8f7: fio.write_bw_MBps -28.6% regression kernel test robot
2019-05-13  3:17 ` kernel test robot
2020-04-10  6:34 ` [LKP] " Xing Zhengjun
2020-04-10  6:35   ` Xing Zhengjun
2020-04-10  6:44   ` [LKP] " Qu Wenruo
2020-04-10  6:44     ` Qu Wenruo
2020-04-10 10:14     ` David Sterba [this message]
2020-04-10 10:14       ` David Sterba
2020-04-13  8:19       ` [LKP] " Xing Zhengjun
2020-04-13  8:20         ` Xing Zhengjun

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=20200410101406.GI5920@suse.cz \
    --to=dsterba@suse.cz \
    --cc=dsterba@suse.com \
    --cc=leonard@lausen.nl \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lkp@01.org \
    --cc=rong.a.chen@intel.com \
    --cc=torvalds@linux-foundation.org \
    --cc=wqu@suse.com \
    --cc=zhengjun.xing@linux.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.