Date: Tue, 27 Sep 2011 17:44:42 -0400 From: George Neville-Neil <gnn@freebsd.org> To: Anton Yuzhaninov <citrin@citrin.ru> Cc: freebsd-performance@freebsd.org Subject: Re: hwpmc overflow Message-ID: <3BE45FDD-1A7A-4F9D-B32B-30D19C897112@freebsd.org> In-Reply-To: <j5btru$rg0$1@dough.gmane.org> References: <j5ae29$e6g$1@dough.gmane.org> <j5asv4$p7e$1@dough.gmane.org> <CAJ-Vmo=m079Dko-erfSdWZaX6nqjxrTVt1U8P0kOK27g5kD8Bw@mail.gmail.com> <j5btru$rg0$1@dough.gmane.org>
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On Sep 21, 2011, at 01:48 , Anton Yuzhaninov wrote: > On Wed, 21 Sep 2011 09:27:33 +0800, Adrian Chadd wrote: > AC> Is this an AMD class CPU? > AC>=20 > AC> The way the counters work on some platforms is that they count = _up_ to > AC> an overflow value, trigger the overflow interrupt, and PMC then is > AC> supposed to calculate what the original value was. > AC> It sounds like maybe that isn't working correctly for a certain = class > AC> of counters? >=20 > CPU: Intel(R) Xeon(R) CPU E5645 @ 2.40GHz >=20 If you count them individually do you still get the overflows? That is, = if you run the same workload but only count instructions, then run it again with = the next counter, etc. I am wondering if something is wrong because of the number of = things you're trying to count at the same time. Best, George
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