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Date: Tue, 20 May 2008 20:09:57 -0400 (EDT)
From: Vince Weaver <vince@csl.cornell.edu>
Subject: Re: [Qemu-devel] Performance Monitoring
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To: qemu-devel@nongnu.org

On Tue, 20 May 2008, Paul Brook wrote:
>
> You probably already know this, but I'd be surprised if the statistics you get
> have much/any correlation with real world performance on modern hardware.

You might be suprised.

I've been adding hooks to Qemu to generate traces for use in computer
architecture research.

I compare the results to hardware performance counters, and things like
branch-prediction, cache miss rates, and total instruction mixes come
across very well (with errors less than 5-10%).  [this is simulating
MIPS and also x86]  Now things that depend a lot on actual timing like
cycle counts and CPI you can't do.

I've actually had a paper published that involves using Qemu in a similar
fashion.  It generates traces at least as good as Valgrind and Pin can.

   http://www.csl.cornell.edu/~vince/papers/hipeac08.html


Vince