From: "H. Peter Anvin" <hpa@zytor.com>
To: "Ma, Ling" <ling.ma@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>,
Ingo Molnar <mingo@elte.hu>, Dave Jones <davej@redhat.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] [X86] Compile Option Os versus O2 on latest x86 platform
Date: Thu, 03 Dec 2009 07:05:55 -0800 [thread overview]
Message-ID: <4B17D3D3.1060502@zytor.com> (raw)
In-Reply-To: <8FED46E8A9CA574792FC7AACAC38FE7714FF5709D9@PDSMSX501.ccr.corp.intel.com>
On 12/03/2009 07:03 AM, Ma, Ling wrote:
>> a key question is.. how much more memory do you have free due to -Os?
>> (because memory is cache is performance on a system level as well)
> The kernel code size from Os is 12M, that from O2 is 14M.
>> and how much less icache pressure is there?
> From perf stat report, cache reference(unified cache) from O2 is almost the same with Os.
The icache pressure was substantially higher (by ~10%) in the reports
that I saw.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2009-12-03 15:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-26 8:05 [PATCH RFC] [X86] Compile Option Os versus O2 on latest x86 platform ling.ma
2009-11-26 9:49 ` Ingo Molnar
2009-12-01 8:54 ` Ma, Ling
2009-12-01 10:14 ` Arjan van de Ven
2009-12-01 16:11 ` H. Peter Anvin
2009-12-03 15:03 ` Ma, Ling
2009-12-03 15:05 ` H. Peter Anvin [this message]
2009-12-03 15:31 ` Ingo Molnar
2009-12-03 15:46 ` H. Peter Anvin
2009-12-02 9:47 ` Ingo Molnar
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=4B17D3D3.1060502@zytor.com \
--to=hpa@zytor.com \
--cc=arjan@infradead.org \
--cc=davej@redhat.com \
--cc=ling.ma@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=tglx@linutronix.de \
/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