From: "Carlos O'Donell" <carlos@redhat.com>
To: Richard Earnshaw <rearnsha@arm.com>
Cc: "Joseph S. Myers" <joseph@codesourcery.com>,
"Shih-Yuan Lee (FourDollars)" <sylee@canonical.com>,
"patches@eglibc.org" <patches@eglibc.org>,
"libc-ports@sourceware.org" <libc-ports@sourceware.org>,
"rex.tsai@canonical.com" <rex.tsai@canonical.com>,
"jesse.sung@canonical.com" <jesse.sung@canonical.com>,
"yc.cheng@canonical.com" <yc.cheng@canonical.com>,
Shih-Yuan Lee <fourdollars@gmail.com>
Subject: Re: [PATCH] ARM: NEON detected memcpy.
Date: Tue, 09 Apr 2013 15:59:00 -0000 [thread overview]
Message-ID: <51643AC9.2050004@redhat.com> (raw)
In-Reply-To: <51642CF3.2040506@arm.com>
On 04/09/2013 11:00 AM, Richard Earnshaw wrote:
>> At present the only policy we have as a community is that faster is
>> always better.
>
>
> You still have to be careful how you measure 'faster'. Repeatedly
> running the same fragment of code under the same boundary conditions
> will only ever give you the 'warm caches' number (I, D and branch
> target), but if the code is called cold (or with different boundary
> conditions in the case of the Branch target cache) most of the time
> in real life, that's unlikely to be very meaningful.
Agreed, but that's what whole system benchmarking is for.
We can't solve all problems at once, and we had zero benchmarking
before we started this work for 2.18.
Hopefully by 2.20 or 2.21 we have some kind of whole system
benchmarking that allows users to monitor their system, gather
data, and submit it back to the project for analysis.
Cheers,
Carlos.
prev parent reply other threads:[~2013-04-09 15:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-03 7:58 Shih-Yuan Lee (FourDollars)
2013-04-03 8:15 ` Will Newton
2013-04-03 9:19 ` Ondřej Bílka
2013-04-03 15:08 ` Joseph S. Myers
2013-04-03 15:48 ` Shih-Yuan Lee (FourDollars)
2013-04-03 16:02 ` Joseph S. Myers
2013-04-04 3:56 ` Shih-Yuan Lee (FourDollars)
2013-04-03 16:20 ` [Patches] " Ondřej Bílka
2013-04-04 4:15 ` Shih-Yuan Lee (FourDollars)
2013-04-04 6:37 ` Ondřej Bílka
2013-04-08 9:12 ` Will Newton
2013-04-08 10:27 ` Ondřej Bílka
2013-04-09 8:45 ` Richard Earnshaw
2013-04-09 9:05 ` Richard Earnshaw
2013-04-09 12:04 ` Ondřej Bílka
2013-04-09 12:59 ` Carlos O'Donell
2013-04-09 15:00 ` Richard Earnshaw
2013-04-09 15:54 ` Ondřej Bílka
2013-04-09 15:59 ` Carlos O'Donell [this message]
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