Messages in this thread | | | Date | Mon, 1 Aug 2011 07:55:40 +0200 | From | Robert Richter <> | Subject | Re: [PATCH 7/7] perf, x86: Implement 64 bit counter support for IBS |
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On 29.07.11 13:02:42, Peter Zijlstra wrote: > On Fri, 2011-07-29 at 18:58 +0200, Peter Zijlstra wrote: > > On Thu, 2011-07-28 at 15:46 +0200, Robert Richter wrote: > > > This patch implements 64 bit counter support for IBS. The sampling > > > period is no longer limited to the hw counter width. > > > > That should never be the case, even for shorter hw counter, in such a > > case you should ignore overflows until you reach the programmed period. > > Hmm, I might have mis-understood, is that exactly what this patch > implements, or does this patch add support for new hardware?
Yes, this patch implements 64 bit counter in software and doesn't add a new hardware feature. It implements 64 bit counting by throwing away interrupts if the period isn't reached.
-Robert
-- Advanced Micro Devices, Inc. Operating System Research Center
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