From: Peter Maydell <peter.maydell@linaro.org>
To: "Emilio G. Cota" <cota@braap.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
"Richard Henderson" <rth@twiddle.net>,
"Laurent Vivier" <laurent@vivier.eu>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Alex Benn�e" <alex.bennee@linaro.org>,
qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] Benchmarking linux-user performance
Date: Sat, 11 Mar 2017 16:02:47 +0100 [thread overview]
Message-ID: <CAFEAcA-dnCGHnh2LCP0Z2=f_ip9DKQTz4gqVC0KrraatcEbeXg@mail.gmail.com> (raw)
In-Reply-To: <20170311022506.GB26530@flamenco>
On 11 March 2017 at 03:25, Emilio G. Cota <cota@braap.org> wrote:
> On Fri, Mar 10, 2017 at 12:48:31 +0100, Peter Maydell wrote:
>> Given the scale on the LHS is from 1.74 to 1.88 my guess is that the
>> variation is in large part noise and the major thing is "our fp
>> performance is bounded by softfloat, which doesn't change and is
>> always very slow".
>
> It isn't "measurement noise" -- if you look at the PNGs the measurements
> are very stable (all points have error bars): http://imgur.com/a/nF7Ls
>
> It's true that performance here varies very little. This is just the
> result of Amdahl's law, as you point out. (upon re-reading your message,
> I see that perhaps what you meant by "noise" is exactly this.)
Yes, sorry, I wasn't really using the right terminology there.
I just meant that the release-to-release variation is not as
significant as it appears from the graph, because the LHS axis
scale is covering such a small range.
thanks
-- PMM
next prev parent reply other threads:[~2017-03-11 15:03 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-10 1:23 [Qemu-devel] Benchmarking linux-user performance Emilio G. Cota
2017-03-10 11:45 ` Dr. David Alan Gilbert
2017-03-10 11:48 ` Peter Maydell
2017-03-11 2:25 ` Emilio G. Cota
2017-03-11 15:02 ` Peter Maydell [this message]
2017-03-11 2:18 ` Emilio G. Cota
2017-03-14 17:06 ` Dr. David Alan Gilbert
2017-03-16 17:13 ` Emilio G. Cota
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