From: Pengfei Yuan <0xcoolypf@gmail.com>
To: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>,
Mike Galbraith <umgwanakikbuti@gmail.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Why not build kernel with -O3
Date: Wed, 8 Apr 2015 21:16:10 +0800 [thread overview]
Message-ID: <CACmZjJ+ZtfKWRjdt3FryViMix2M4r=OT=Tb9ntrU-P4T=vXNdQ@mail.gmail.com> (raw)
In-Reply-To: <CAFLxGvzZuddx=GA5HTZzJb_=_6U9RRSDS-iRoer7u8T8p8VrmA@mail.gmail.com>
2015-04-08 20:19 GMT+08:00 Richard Weinberger <richard.weinberger@gmail.com>:
> On Wed, Apr 8, 2015 at 3:00 AM, Pengfei Yuan <0xcoolypf@gmail.com> wrote:
>> Could you please provide some examples that I can investigate?
>> Thanks!
>
> It would be awesome if you could find out which gcc optimizations
> cause the speed up.
> "gcc -c -Q -O3 --help=optimizers" will help you.
>
This is really helpful.
But I can only find very short description for each option from
https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
> Please also double check your results.
> You need do to multiple runs, etc...
> Especially the redis speed up looks odd. Does redis really spend that much time
> in the kernel?
Redis is special among the six applications because it is single-threaded.
Yuan
next prev parent reply other threads:[~2015-04-08 13:16 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-07 3:37 Why not build kernel with -O3 Pengfei Yuan
2015-04-07 6:43 ` Mike Galbraith
2015-04-07 7:07 ` Boaz Harrosh
2015-04-07 8:29 ` Mike Galbraith
2015-04-07 7:56 ` Pengfei Yuan
2015-04-07 10:09 ` Mike Galbraith
2015-04-07 18:05 ` Austin S Hemmelgarn
2015-04-08 1:00 ` Pengfei Yuan
2015-04-08 12:06 ` Austin S Hemmelgarn
2015-04-08 12:57 ` One Thousand Gnomes
2015-04-08 13:19 ` Pengfei Yuan
2015-04-08 13:53 ` Austin S Hemmelgarn
2015-04-08 12:19 ` Richard Weinberger
2015-04-08 12:49 ` Austin S Hemmelgarn
2015-04-08 13:16 ` Pengfei Yuan [this message]
2015-04-08 13:21 ` Richard Weinberger
2015-04-27 20:37 ` Pavel Machek
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='CACmZjJ+ZtfKWRjdt3FryViMix2M4r=OT=Tb9ntrU-P4T=vXNdQ@mail.gmail.com' \
--to=0xcoolypf@gmail.com \
--cc=ahferroin7@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=richard.weinberger@gmail.com \
--cc=umgwanakikbuti@gmail.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).