diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event_p4.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c index 424fc8de68e4..02f072830237 100644 --- a/arch/x86/kernel/cpu/perf_event_p4.c +++ b/arch/x86/kernel/cpu/perf_event_p4.c @@ -465,15 +465,21 @@ out: return rc; } -static inline void p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc) +static inline int p4_pmu_clear_cccr_ovf(struct hw_perf_event *hwc) { - unsigned long dummy; + int overflow = 0; + u32 low, high; - rdmsrl(hwc->config_base + hwc->idx, dummy); - if (dummy & P4_CCCR_OVF) { + rdmsr(hwc->config_base + hwc->idx, low, high); + + /* we need to check high bit for unflagged overflows */ + if ((low & P4_CCCR_OVF) || (high & (1 << 31))) { + overflow = 1; (void)checking_wrmsrl(hwc->config_base + hwc->idx, - ((u64)dummy) & ~P4_CCCR_OVF); + ((u64)low) & ~P4_CCCR_OVF); } + + return overflow; } static inline void p4_pmu_disable_event(struct perf_event *event) @@ -584,21 +590,15 @@ static int p4_pmu_handle_irq(struct pt_regs *regs) WARN_ON_ONCE(hwc->idx != idx); - /* - * FIXME: Redundant call, actually not needed - * but just to check if we're screwed - */ - p4_pmu_clear_cccr_ovf(hwc); + /* it might be unflagged overflow */ + handled = p4_pmu_clear_cccr_ovf(hwc); val = x86_perf_event_update(event); - if (val & (1ULL << (x86_pmu.cntval_bits - 1))) + if (!handled && (val & (1ULL << (x86_pmu.cntval_bits - 1)))) continue; - /* - * event overflow - */ - handled = 1; - data.period = event->hw.last_period; + /* event overflow for sure */ + data.period = event->hw.last_period; if (!x86_perf_event_set_period(event)) continue; |