Messages in this thread | | | Subject | Re: [PATCH V6 07/14] perf/x86/intel: Generic support for hardware TopDown metrics | From | "Liang, Kan" <> | Date | Mon, 20 Jul 2020 14:11:54 -0400 |
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On 7/20/2020 1:41 PM, Peter Zijlstra wrote: > On Fri, Jul 17, 2020 at 07:05:47AM -0700, kan.liang@linux.intel.com wrote: > >> For the event mapping, a special 0x00 event code is used, which is >> reserved for fake events. The metric events start from umask 0x10. > >> +#define INTEL_PMC_IDX_METRIC_BASE (INTEL_PMC_IDX_FIXED + 16) >> +#define INTEL_PMC_IDX_TD_RETIRING (INTEL_PMC_IDX_METRIC_BASE + 0) >> +#define INTEL_PMC_IDX_TD_BAD_SPEC (INTEL_PMC_IDX_METRIC_BASE + 1) >> +#define INTEL_PMC_IDX_TD_FE_BOUND (INTEL_PMC_IDX_METRIC_BASE + 2) >> +#define INTEL_PMC_IDX_TD_BE_BOUND (INTEL_PMC_IDX_METRIC_BASE + 3) > > So this is internal and we can change it around if/when needed, right? >
Yes
>> +#define INTEL_PMC_IDX_METRIC_END INTEL_PMC_IDX_TD_BE_BOUND >> +#define INTEL_PMC_MSK_TOPDOWN ((0xfull << INTEL_PMC_IDX_METRIC_BASE) | \ >> + INTEL_PMC_MSK_FIXED_SLOTS) >> + >> +/* >> + * There is no event-code assigned to the TopDown events. >> + * >> + * For the slots event, use the pseudo code of the fixed counter 3. >> + * >> + * For the metric events, the pseudo event-code is 0x00. >> + * The pseudo umask-code starts from 0x10. >> + */ >> +#define INTEL_TD_SLOTS 0x0400 /* TOPDOWN.SLOTS */ >> +/* Level 1 metrics */ >> +#define INTEL_TD_METRIC_RETIRING 0x1000 /* Retiring metric */ >> +#define INTEL_TD_METRIC_BAD_SPEC 0x1100 /* Bad speculation metric */ >> +#define INTEL_TD_METRIC_FE_BOUND 0x1200 /* FE bound metric */ >> +#define INTEL_TD_METRIC_BE_BOUND 0x1300 /* BE bound metric */ >> +#define INTEL_TD_METRIC_MAX INTEL_TD_METRIC_BE_BOUND >> +#define INTEL_TD_METRIC_NUM 4 > > But this is ABI, once we merge this, it's stuck. > > Also, per how Fixed2 is 0x0300, should not Fixed16 (aka > METRICS_RETIRING) be 0x1100 ? > > But aside of that, are we sure the hardware will never grow a Fixed16? > Or do we want to be paranoid and move the metrics events up in the > pseudo event space? >
Right, we cannot guarantee that the number of fixed counters is always less than 16.
I will move the metrics events to the middle of the pseudo event space.
+#define INTEL_TD_METRIC_RETIRING 0x8000 /* Retiring metric */ +#define INTEL_TD_METRIC_BAD_SPEC 0x8100 /* Bad speculation metric */ +#define INTEL_TD_METRIC_FE_BOUND 0x8200 /* FE bound metric */ +#define INTEL_TD_METRIC_BE_BOUND 0x8300 /* BE bound metric */
Thanks, Kan
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