Messages in this thread | | | Date | Thu, 6 Aug 2015 13:38:21 -0700 | Subject | Re: [PATCH V2 1/1] perf/x86: Add Intel power cstate PMUs support | From | Stephane Eranian <> |
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On Thu, Aug 6, 2015 at 1:25 PM, Liang, Kan <kan.liang@intel.com> wrote: > >> >> >> >> +static cpumask_t power_cstate_core_cpu_mask; >> >> >> > >> >> >> > That one typically does not need a cpumask. >> >> >> > >> >> >> You need to pick one CPU out of the multi-core. But it is for >> >> >> client parts thus there is only one socket. At least this is my >> understanding. >> >> >> >> >> > >> >> > CORE_C*_RESIDENCY are available for physical processor core. >> >> > So logical processor in same physical processor core share the same >> >> > counter. >> >> > I think we need the cpumask to identify the default logical >> >> > processor which do counting. >> >> > >> >> Did you restrict these events to system-wide mode only? >> >> >> Ok, so that means that your cpumask includes one HT per physical core. >> But then, the result is not the simple aggregation of all the N/2 CPUs. > > The counter counts per physical core. The result is the aggregation of > all HT cpus in same physical core.
But then don't you need to divide by 2 to get a meaningful result?
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