diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_counter.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index a8a53ab..4b8715b 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -54,6 +54,7 @@ struct x86_pmu { int num_counters_fixed; int counter_bits; u64 counter_mask; + u64 max_period; }; static struct x86_pmu x86_pmu __read_mostly; @@ -279,14 +280,8 @@ static int __hw_perf_counter_init(struct perf_counter *counter) hwc->nmi = 1; hwc->irq_period = hw_event->irq_period; - /* - * Intel PMCs cannot be accessed sanely above 32 bit width, - * so we install an artificial 1<<31 period regardless of - * the generic counter period: - */ - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - if ((s64)hwc->irq_period <= 0 || hwc->irq_period > 0x7FFFFFFF) - hwc->irq_period = 0x7FFFFFFF; + if ((s64)hwc->irq_period <= 0 || hwc->irq_period > x86_pmu.max_period) + hwc->irq_period = x86_pmu.max_period; atomic64_set(&hwc->period_left, hwc->irq_period); @@ -910,6 +905,12 @@ static struct x86_pmu intel_pmu = { .event_map = intel_pmu_event_map, .raw_event = intel_pmu_raw_event, .max_events = ARRAY_SIZE(intel_perfmon_event_map), + /* + * Intel PMCs cannot be accessed sanely above 32 bit width, + * so we install an artificial 1<<31 period regardless of + * the generic counter period: + */ + .max_period = (1ULL << 31) - 1, }; static struct x86_pmu amd_pmu = { @@ -927,6 +928,8 @@ static struct x86_pmu amd_pmu = { .num_counters = 4, .counter_bits = 48, .counter_mask = (1ULL << 48) - 1, + /* use highest bit to detect overflow */ + .max_period = (1ULL << 47) - 1, }; static int intel_pmu_init(void) @@ -999,6 +1002,7 @@ void __init init_hw_perf_counters(void) perf_max_counters = x86_pmu.num_counters; pr_info("... value mask: %016Lx\n", x86_pmu.counter_mask); + pr_info("... max period: %016Lx\n", x86_pmu.max_period); if (x86_pmu.num_counters_fixed > X86_PMC_MAX_FIXED) { x86_pmu.num_counters_fixed = X86_PMC_MAX_FIXED; |