On Fri, Apr 09, 2021 at 09:50:20AM -0400, Liang, Kan wrote: > > > On 4/9/2021 2:58 AM, Peter Zijlstra wrote: > > On Mon, Apr 05, 2021 at 08:10:58AM -0700, [email protected] wrote: > > > @@ -2089,9 +2119,46 @@ static int __init init_hw_perf_events(void) > > > if (err) > > > goto out1; > > > - err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW); > > > - if (err) > > > - goto out2; > > > + if (!is_hybrid()) { > > > + err = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW); > > > + if (err) > > > + goto out2; > > > + } else { > > > + u8 cpu_type = get_this_hybrid_cpu_type(); > > > + struct x86_hybrid_pmu *hybrid_pmu; > > > + bool registered = false; > > > + int i; > > > + > > > + if (!cpu_type && x86_pmu.get_hybrid_cpu_type) > > > + cpu_type = x86_pmu.get_hybrid_cpu_type(); > > > + > > > + for (i = 0; i < x86_pmu.num_hybrid_pmus; i++) { > > > + hybrid_pmu = &x86_pmu.hybrid_pmu[i]; > > > + > > > + hybrid_pmu->pmu = pmu; > > > + hybrid_pmu->pmu.type = -1; > > > + hybrid_pmu->pmu.attr_update = x86_pmu.attr_update; > > > + hybrid_pmu->pmu.capabilities |= > > > PERF_PMU_CAP_HETEROGENEOUS_CPUS; > > > + > > > + err = perf_pmu_register(&hybrid_pmu->pmu, > > > hybrid_pmu->name, > > > + (hybrid_pmu->cpu_type == > > > hybrid_big) ? PERF_TYPE_RAW : -1); > > > + if (err) > > > + continue; > > > + > > > + if (cpu_type == hybrid_pmu->cpu_type) > > > + x86_pmu_update_cpu_context(&hybrid_pmu->pmu, > > > raw_smp_processor_id()); > > > + > > > + registered = true; > > > + } > > > + > > > + if (!registered) { > > > + pr_warn("Failed to register hybrid PMUs\n"); > > > + kfree(x86_pmu.hybrid_pmu); > > > + x86_pmu.hybrid_pmu = NULL; > > > + x86_pmu.num_hybrid_pmus = 0; > > > + goto out2; > > > + } > > > > I don't think this is quite right. registered will be true even if one > > fails, while I think you meant to only have it true when all (both) > > types registered correctly. > > No, I mean that perf error out only when all types fail to be registered.
All or nothing seems a better approach to me. There really isn't a good reason for any one of them to fail.
