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From: Peter Zijlstra <peterz@infradead.org>
To: Tim Blechmann <tim@klingt.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: perf: counter and event question
Date: Mon, 28 Dec 2009 14:03:33 +0100	[thread overview]
Message-ID: <1262005413.7135.98.camel@laptop> (raw)
In-Reply-To: <4B38A707.4060904@klingt.org>

On Mon, 2009-12-28 at 13:39 +0100, Tim Blechmann wrote:
> On 12/28/2009 12:26 PM, Peter Zijlstra wrote:
> > On Mon, 2009-12-28 at 12:16 +0100, Tim Blechmann wrote:
> >> like it is impossible to sample instructions with a period of 1? 
> > 
> > Pretty much, imagine the cpu getting a trap every cycle.
> 
> is this a hardware restriction? a slowdown is acceptable for me, as long
> as i am able to collect a huge number of samples accurately ...

Large number of samples and sample interval are only related through the
runtime of your application.

Use a sensible period (~10k ins) and run a 'little' longer.




  reply	other threads:[~2009-12-28 13:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-28 11:16 perf: counter and event question Tim Blechmann
2009-12-28 11:26 ` Peter Zijlstra
2009-12-28 12:39   ` Tim Blechmann
2009-12-28 13:03     ` Peter Zijlstra [this message]
2009-12-28 13:09       ` Tim Blechmann
2009-12-28 14:02         ` Peter Zijlstra

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