From: Borislav Petkov <bp@alien8.de>
To: Jinhua Wu <wujinhua@linux.alibaba.com>
Cc: x86@kernel.org, zelin.deng@linux.alibaba.com,
jiayu.ni@linux.alibaba.com, ak@linux.intel.com,
luming.yu@intel.com, fan.du@intel.com,
artie.ding@linux.alibaba.com, tony.luck@intel.com,
tglx@linutronix.de, linux-kernel@vger.kernel.org,
pawan.kumar.gupta@linux.intel.com, fenghua.yu@intel.com,
hpa@zytor.com, ricardo.neri-calderon@linux.intel.com,
peterz@infradead.org
Subject: Re: [PATCH] perf: optimize clear page in Intel specified model with movq instruction
Date: Thu, 9 Sep 2021 11:39:40 +0200 [thread overview]
Message-ID: <YTnWXIB42sCLbM2k@zn.tnic> (raw)
In-Reply-To: <1631177151-53723-1-git-send-email-wujinhua@linux.alibaba.com>
On Thu, Sep 09, 2021 at 04:45:51PM +0800, Jinhua Wu wrote:
> Clear page is the most time-consuming procedure in page fault handling.
> Kernel use fast-string instruction to clear page. We found that in specified
> Intel model such as CPX and ICX, the movq instruction perform much better
> than fast-string instruction when corresponding page is not in cache.
> But when the page is in cache, fast string perform better. We show the test
> result in the following:
What you should do is show the extensive tests you've run with
real-world benchmarks where you really can show 40% performance
improvement.
Also, the static branch "approach" you're using ain't gonna happen. If
anything, another X86_FEATURE_* bit.
Good luck.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-09-09 9:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-09 8:45 [PATCH] perf: optimize clear page in Intel specified model with movq instruction Jinhua Wu
2021-09-09 9:39 ` Borislav Petkov [this message]
2021-09-09 10:34 ` Luming Yu
2021-09-09 10:44 ` Borislav Petkov
2021-09-09 11:18 ` Peter Zijlstra
[not found] ` <bf6fe59d-c760-40d4-8201-4170cd90ffc3.wujinhua@linux.alibaba.com>
2021-09-09 11:07 ` 回复：[PATCH] " Borislav Petkov
2021-09-09 14:51 ` Luming Yu
[not found] ` <1cac1499-6b00-3c18-b64c-a22f269a2706@linux.alibaba.com>
2021-10-16 13:22 ` Borislav Petkov
[not found] ` <7b07f141-12f5-397d-9e45-1d507cacae84@linux.alibaba.com>
2021-10-18 12:43 ` Borislav Petkov
2021-10-18 14:44 ` Luming Yu
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=YTnWXIB42sCLbM2k@zn.tnic \
--to=bp@alien8.de \
--cc=ak@linux.intel.com \
--cc=artie.ding@linux.alibaba.com \
--cc=fan.du@intel.com \
--cc=fenghua.yu@intel.com \
--cc=hpa@zytor.com \
--cc=jiayu.ni@linux.alibaba.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luming.yu@intel.com \
--cc=pawan.kumar.gupta@linux.intel.com \
--cc=peterz@infradead.org \
--cc=ricardo.neri-calderon@linux.intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=wujinhua@linux.alibaba.com \
--cc=x86@kernel.org \
--cc=zelin.deng@linux.alibaba.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).