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Date:   Wed, 28 Aug 2019 18:28:57 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Andi Kleen <ak@linux.intel.com>
Cc:     kan.liang@linux.intel.com, acme@kernel.org, mingo@redhat.com,
        linux-kernel@vger.kernel.org, tglx@linutronix.de, jolsa@kernel.org,
        eranian@google.com, alexander.shishkin@linux.intel.com
Subject: Re: [RESEND PATCH V3 3/8] perf/x86/intel: Support hardware TopDown
 metrics
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On Wed, Aug 28, 2019 at 09:17:54AM -0700, Andi Kleen wrote:
> > This really doesn't make sense to me; if you set FIXED_CTR3 := 0, you'll
> > never trigger the overflow there; this then seems to suggest the actual
> 
> The 48bit counter might overflow in a few hours.

Sure; the point is? Kan said it should not be too big; a full 48bit wrap
around must be too big or nothing is.