From: Huang Ying <ying.huang@intel.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>, LKP ML <lkp@01.org>
Subject: Re: [LKP] [futex] 76835b0ebf8: -8.1% will-it-scale.per_thread_ops
Date: Fri, 27 Feb 2015 11:28:51 +0800 [thread overview]
Message-ID: <1425007731.10337.50.camel@intel.com> (raw)
In-Reply-To: <20150226095812.GA32538@localhost>
Hi, Catalin,
On Thu, 2015-02-26 at 09:58 +0000, Catalin Marinas wrote:
> On Thu, Feb 26, 2015 at 05:16:53AM +0000, Huang Ying wrote:
> > FYI, we noticed the below changes on
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > commit 76835b0ebf8a7fe85beb03c75121419a7dec52f0 ("futex: Ensure get_futex_key_refs() always implies a barrier")
> >
> >
> > testbox/testcase/testparams: lkp-wsx01/will-it-scale/performance-futex4
> >
> > 0429fbc0bdc297d6 76835b0ebf8a7fe85beb03c751
> > ---------------- --------------------------
> > %stddev %change %stddev
> > \ | \
> > 6314259 ± 0% -8.1% 5800079 ± 0% will-it-scale.per_thread_ops
> > 6274871 ± 0% -8.1% 5768747 ± 0% will-it-scale.per_process_ops
>
> This was raised before but I'm not sure we can do much about it:
>
> https://lkml.org/lkml/2014/10/26/189
Sorry for duplicated report.
> It would be interesting to know the difference in performance with the
> code prior to commits b0c29f79ecea and 11d4616bd07f which optimised the
> futex code but missed a barrier.
I will do some test for that.
Best Regards,
Huang, Ying
prev parent reply other threads:[~2015-02-27 3:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-26 5:16 [LKP] [futex] 76835b0ebf8: -8.1% will-it-scale.per_thread_ops Huang Ying
2015-02-26 9:58 ` Catalin Marinas
2015-02-27 3:28 ` Huang Ying [this message]
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=1425007731.10337.50.camel@intel.com \
--to=ying.huang@intel.com \
--cc=catalin.marinas@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lkp@01.org \
--cc=torvalds@linux-foundation.org \
/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