On Thu, Mar 11, 2021 at 05:09:25PM +0100, Peter Zijlstra wrote: > On Wed, Mar 10, 2021 at 08:37:56AM -0800, kan.li...@linux.intel.com wrote: > > From: Kan Liang <kan.li...@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?
