PERF_PMU_CAP_AUX_OUTPUT
if (!(pmu.capabilities & PERF_PMU_CAP_AUX_OUTPUT))
x86_get_pmu(smp_processor_id())->capabilities |= PERF_PMU_CAP_AUX_OUTPUT;
(!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT) ||