Date: Thu, 23 Feb 2006 15:36:01 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: current@FreeBSD.org Subject: Re: The sixty second pmc howto Message-ID: <20060223153135.C9642@fledge.watson.org> In-Reply-To: <17405.53911.686306.362353@grasshopper.cs.duke.edu> References: <20060223143856.O9642@fledge.watson.org> <17405.53911.686306.362353@grasshopper.cs.duke.edu>
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On Thu, 23 Feb 2006, Andrew Gallatin wrote: > Robert Watson writes: > > > (2) Run "pmcstat -S instructions -O /tmp/sample.out" to start sampling of > > instruction retirement events, saving the results to /tmp/sample.out. > > Dumb question, but what does "instructions" really mean? The number of > instructions, the time spent executing them, ? pmcstat magically translates 'instructions' into 'p4-instr-retired', which might well refer to what happens to an instruction when it is believed to have successfully executed. Presumably this happens once you know it hasn't been mispredicted, etc, but I'm sure someone can give a better and more detailed answer. Robert N M Watson
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