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Groups > linux.kernel > #1532515
| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] perf/x86: fix event counter update issue |
| Date | 2016-11-29 18:00 +0100 |
| Message-ID | <sITV8-2B3-17@gated-at.bofh.it> (permalink) |
| References | <sIzMJ-6iD-5@gated-at.bofh.it> <sIMTD-6Co-23@gated-at.bofh.it> <sIRTj-1hD-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue, Nov 29, 2016 at 02:46:14PM +0000, Liang, Kan wrote:
> > And note that we _ALWAYS_ set the IN bits, even for !sampling events.
> > Also note we set max_period to (1<<31) - 1, so we should never exceed 31
> > bits.
> >
>
> The max_period is 0xfffffffff.
>
> The limit is breaked by this patch.
> 069e0c3c4058 ("perf/x86/intel: Support full width counting")
> https://patchwork.kernel.org/patch/2784191/
>
> /* Support full width counters using alternative MSR range */
> if (x86_pmu.intel_cap.full_width_write) {
> x86_pmu.max_period = x86_pmu.cntval_mask;
> x86_pmu.perfctr = MSR_IA32_PMC0;
> pr_cont("full-width counters, ");
> }
>
Wth do KNL/SLM have full_width_write set if they have short counters? I
should the whole point of the full_wdith thing was that in that case the
counters were actually 64bit wide.
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[PATCH] perf/x86: fix event counter update issue kan.liang@intel.com - 2016-11-28 20:30 +0100
Re: [PATCH] perf/x86: fix event counter update issue Stephane Eranian <eranian@google.com> - 2016-11-28 20:50 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Liang, Kan" <kan.liang@intel.com> - 2016-11-28 21:10 +0100
Re: [PATCH] perf/x86: fix event counter update issue Stephane Eranian <eranian@google.com> - 2016-11-28 21:20 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Liang, Kan" <kan.liang@intel.com> - 2016-11-28 21:30 +0100
Re: [PATCH] perf/x86: fix event counter update issue Peter Zijlstra <peterz@infradead.org> - 2016-11-29 10:30 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Liang, Kan" <kan.liang@intel.com> - 2016-11-29 15:50 +0100
Re: [PATCH] perf/x86: fix event counter update issue Peter Zijlstra <peterz@infradead.org> - 2016-11-29 18:00 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Liang, Kan" <kan.liang@intel.com> - 2016-11-29 18:10 +0100
Re: [PATCH] perf/x86: fix event counter update issue Peter Zijlstra <peterz@infradead.org> - 2016-11-29 18:20 +0100
Re: [PATCH] perf/x86: fix event counter update issue Stephane Eranian <eranian@google.com> - 2016-11-29 18:30 +0100
Re: [PATCH] perf/x86: fix event counter update issue Peter Zijlstra <peterz@infradead.org> - 2016-11-29 18:40 +0100
Re: [PATCH] perf/x86: fix event counter update issue Stephane Eranian <eranian@google.com> - 2016-11-29 19:20 +0100
Re: [PATCH] perf/x86: fix event counter update issue Andi Kleen <ak@linux.intel.com> - 2016-11-29 19:40 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Liang, Kan" <kan.liang@intel.com> - 2016-11-29 20:10 +0100
Re: [PATCH] perf/x86: fix event counter update issue Peter Zijlstra <peterz@infradead.org> - 2016-11-29 20:40 +0100
Re: [PATCH] perf/x86: fix event counter update issue Stephane Eranian <eranian@google.com> - 2016-11-29 21:40 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Liang, Kan" <kan.liang@intel.com> - 2016-11-29 21:40 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Odzioba, Lukasz" <lukasz.odzioba@intel.com> - 2016-12-02 14:00 +0100
Re: [PATCH] perf/x86: fix event counter update issue Peter Zijlstra <peterz@infradead.org> - 2016-12-05 11:30 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Odzioba, Lukasz" <lukasz.odzioba@intel.com> - 2016-12-05 12:30 +0100
RE: [PATCH] perf/x86: fix event counter update issue "Odzioba, Lukasz" <lukasz.odzioba@intel.com> - 2016-11-29 20:10 +0100
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