Messages in this thread | | | Subject | Re: [PATCH V2 20/25] perf/x86/intel: Add Alder Lake Hybrid support | From | "Liang, Kan" <> | Date | Thu, 11 Mar 2021 12:31:06 -0500 |
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On 3/11/2021 11:32 AM, Peter Zijlstra wrote: > On Thu, Mar 11, 2021 at 05:09:25PM +0100, Peter Zijlstra wrote: >> On Wed, Mar 10, 2021 at 08:37:56AM -0800, kan.liang@linux.intel.com wrote: >>> From: Kan Liang <kan.liang@linux.intel.com> >>> >>> Alder Lake Hybrid system has two different types of core, Golden Cove >>> core and Gracemont core. The Golden Cove core is registered to >>> "cpu_core" PMU. The Gracemont core is registered to "cpu_atom" PMU. >>> >>> The difference between the two PMUs include: >>> - Number of GP and fixed counters >>> - Events >>> - The "cpu_core" PMU supports Topdown metrics. >>> The "cpu_atom" PMU supports PEBS-via-PT. >>> >>> The "cpu_core" PMU is similar to the Sapphire Rapids PMU, but without >>> PMEM. >>> The "cpu_atom" PMU is similar to Tremont, but with different >>> event_constraints, extra_regs and number of counters. >>> >> >>> + /* Initialize big core specific PerfMon capabilities.*/ >>> + pmu = &x86_pmu.hybrid_pmu[X86_HYBRID_PMU_CORE_IDX]; >>> + pmu->name = "cpu_core"; >> >>> + /* Initialize Atom core specific PerfMon capabilities.*/ >>> + pmu = &x86_pmu.hybrid_pmu[X86_HYBRID_PMU_ATOM_IDX]; >>> + pmu->name = "cpu_atom"; >> >> So do these things use the same event lists as SPR and TNT? Is there any >> way to discover that, because AFAICT /proc/cpuinfo will say every CPU >> is 'Alderlake', and the above also doesn't give any clue. >> >> FWIW, ARM big.LITTLE does discriminate in its /proc/cpuinfo, but I'm not >> entirely sure it's really useful. Mark said perf userspace uses >> somethink akin to our CPUID, except exposed through sysfs, to find the >> event lists. >> >> My desktop has: cpu/caps/pmu_name and that gives "skylake", do we want >> the above to have cpu_core/caps/pmu_name give "sapphire_rapids" etc.. ? > > FWIW, "Tremont" is the only pmu_name with a capital :-( I don't suppose > we can still fix that? >
The cpu/caps/pmu_name is not used for the event list.
I don't think perf tool checks the "Tremont". I think it should be OK to fix it. Let me post a patch.
Thanks, Kan
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