Messages in this thread | | | Date | Fri, 22 Apr 2011 12:43:38 +0400 | Subject | Re: [PATCH 4/4] perf, x86: Add PERF_COUNT_HW_NMI_WATCHDOG event | From | Cyrill Gorcunov <> |
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P4 cant move events between counters in compare with architectural event so when nmi-watchdog is used perf top is blocked because it needs same counters but the counters already borrowed for watchdog. as result we need a different event and counters for watchdog.
Ingo, nonsleeping cycles is from intel sdm, so when someone start reading this code in future will find this term in sdm fast. or i could put the reference from sdm itself here, hm?
On Friday, April 22, 2011, Ingo Molnar <mingo@elte.hu> wrote: > > * Don Zickus <dzickus@redhat.com> wrote: > >> From: Cyrill Gorcunov <gorcunov@gmail.com> >> >> Due to restriction and specifics of Netburst PMU we need >> a separated event for NMI watchdog. Note that on all other >> than P4 PMU cpus this event is a simple alias for PERF_COUNT_HW_CPU_CYCLES. >> >> This event is only used by x86 for now so no other archs involved. > > hm, there's no explanation exactly why this is needed and what the alternatives > are. > > This sentence: > >> + /* we use that named non-sleeping calls */ > > does not parse for me. > > Thanks, > > Ingo > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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