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From: Pengfei Yuan <0xcoolypf@gmail.com>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Why not build kernel with -O3
Date: Tue, 7 Apr 2015 15:56:16 +0800	[thread overview]
Message-ID: <CACmZjJLLiML0wgojfxDujqusiYGvp=u1fPs7wMmXDaDcm55nOQ@mail.gmail.com> (raw)
In-Reply-To: <1428388995.3152.10.camel@gmail.com>

I am trying legacy GCC versions.
But I am not able to try different architectures.

2015-04-07 14:43 GMT+08:00 Mike Galbraith <umgwanakikbuti@gmail.com>:
> On Tue, 2015-04-07 at 11:37 +0800, Pengfei Yuan wrote:
>> Hi,
>>
>> I have conducted some experiments to compare kernels built with -O2
>> and -O3. Here are the results:
>>
>> Application  Performance O2   Performance O3   Improvement
>> Apache       127814.14 req/s  130321.24 req/s  1.96%
>> Nginx        537589.08 req/s  556723.32 req/s  3.56%
>> MySQL        70661.38 tx/s    71008.47 tx/s    0.49%
>> PostgreSQL   79763.39 tx/s    79535.59 tx/s    -0.29%
>> Redis        352547.47 op/s   405417.24 op/s   15.0%
>> Memcached    844439.14 op/s   845321.79 op/s   0.10%
>>
>> Geomean: +3.34%
>>
>> Experiment environment: Linux 3.19.3, GCC 4.9.3 prerelease, Core-i7
>> 4770, 32G RAM, 10GbE
>>
>> LMbench microbenchmark also shows reduction in various latencies, as
>> well as increase of throughputs.
>
> Please show multiple run data for all permutations of supported gcc
> version/arch ;-)
>
>         -Mike

  parent reply	other threads:[~2015-04-07  7:56 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 [this message]
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
2015-04-08 13:21               ` Richard Weinberger
2015-04-27 20:37 ` Pavel Machek

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