From 2b9e344df384e595db24ac61ae5f780e9b024878 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 12 Sep 2013 12:53:44 +0200 Subject: [PATCH] perf/x86/intel: Clean up checkpoint-interrupt bits Clean up the weird CP interrupt exception code by keeping a CP mask. Andi suggested this implementation but weirdly didn't actually implement it himself, do so now because it removes the conditional in the interrupt handler and avoids the assumption its only on cnt2. Suggested-by: Andi Kleen Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-dvb4q0rydkfp00kqat4p5bah@git.kernel.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.h | 5 +++++ arch/x86/kernel/cpu/perf_event_intel.c | 22 +++++++++++++--------- 2 files changed, 18 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h index cc16faae0538..ce84edeeae27 100644 --- a/arch/x86/kernel/cpu/perf_event.h +++ b/arch/x86/kernel/cpu/perf_event.h @@ -163,6 +163,11 @@ struct cpu_hw_events { u64 intel_ctrl_host_mask; struct perf_guest_switch_msr guest_switch_msrs[X86_PMC_IDX_MAX]; + /* + * Intel checkpoint mask + */ + u64 intel_cp_status; + /* * manage shared (per-core, per-cpu) registers * used on Intel NHM/WSM/SNB diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index dd1d4f3e18e6..ec70d0cce555 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1184,6 +1184,11 @@ static void intel_pmu_disable_fixed(struct hw_perf_event *hwc) wrmsrl(hwc->config_base, ctrl_val); } +static inline bool event_is_checkpointed(struct perf_event *event) +{ + return (event->hw.config & HSW_IN_TX_CHECKPOINTED) != 0; +} + static void intel_pmu_disable_event(struct perf_event *event) { struct hw_perf_event *hwc = &event->hw; @@ -1197,6 +1202,7 @@ static void intel_pmu_disable_event(struct perf_event *event) cpuc->intel_ctrl_guest_mask &= ~(1ull << hwc->idx); cpuc->intel_ctrl_host_mask &= ~(1ull << hwc->idx); + cpuc->intel_cp_status &= ~(1ull << hwc->idx); /* * must disable before any actual event @@ -1271,6 +1277,9 @@ static void intel_pmu_enable_event(struct perf_event *event) if (event->attr.exclude_guest) cpuc->intel_ctrl_host_mask |= (1ull << hwc->idx); + if (unlikely(event_is_checkpointed(event))) + cpuc->intel_cp_status |= (1ull << hwc->idx); + if (unlikely(hwc->config_base == MSR_ARCH_PERFMON_FIXED_CTR_CTRL)) { intel_pmu_enable_fixed(hwc); return; @@ -1282,11 +1291,6 @@ static void intel_pmu_enable_event(struct perf_event *event) __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE); } -static inline bool event_is_checkpointed(struct perf_event *event) -{ - return (event->hw.config & HSW_IN_TX_CHECKPOINTED) != 0; -} - /* * Save and restart an expired event. Called by NMI contexts, * so it has to be careful about preempting normal event ops: @@ -1389,11 +1393,11 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) } /* - * To avoid spurious interrupts with perf stat always reset checkpointed - * counters. + * Checkpointed counters can lead to 'spurious' PMIs because the + * rollback caused by the PMI will have cleared the overflow status + * bit. Therefore always force probe these counters. */ - if (cpuc->events[2] && event_is_checkpointed(cpuc->events[2])) - status |= (1ULL << 2); + status |= cpuc->intel_cp_status; for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) { struct perf_event *event = cpuc->events[bit]; -- 2.45.2