Re: [patch] Performance Counters for Linux, v2

From: Chris Friesen
Date: Tue Dec 09 2008 - 12:35:52 EST


Will Newton wrote:
On Tue, Dec 9, 2008 at 1:46 PM, Ingo Molnar <mingo@xxxxxxx> wrote:

Firstly, sampling "at 1msec intervals" or any fixed period is a _very_
wrong mindset - and cross-sampling counters is a similarly wrong mindset.

If your hardware does not interrupt on overflow I don't think you have
any choice in the matter. I know such hardware is less than ideal but
it exists so it should be supported.

I think you could still set up the counters as Ingo describes and then sample the counters (as opposed to the program) at a suitable interval (chosen such that the counters won't overflow more than once between samples).

Chris
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