From ec71a398c1bf6d8188cb24ebab6f5202523d95e1 Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Thu, 8 Mar 2018 18:15:41 -0800 Subject: [PATCH] perf/x86/intel/ds: Handle PEBS overflow for fixed counters The pebs_drain() need to support fixed counters. The DS Save Area now include "counter reset value" fields for each fixed counters. Extend the related variables (e.g. mask, counters, error) to support fixed counters. There is no extended PEBS in PEBS v2 and earlier PEBS format. Only need to change the code for PEBS v3 and later PEBS format. Extend the pebs_event_reset[] logic to support new "counter reset value" fields. Increase the reserve space for fixed counters. Based-on-code-from: Andi Kleen Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: acme@kernel.org Link: http://lkml.kernel.org/r/20180309021542.11374-3-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/events/intel/core.c | 5 ++++- arch/x86/events/intel/ds.c | 36 +++++++++++++++++++++++++++--------- arch/x86/include/asm/intel_ds.h | 3 ++- 3 files changed, 33 insertions(+), 11 deletions(-) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index d5a3124..b1a49a1 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2282,7 +2282,10 @@ again: * counters from the GLOBAL_STATUS mask and we always process PEBS * events via drain_pebs(). */ - status &= ~(cpuc->pebs_enabled & PEBS_COUNTER_MASK); + if (x86_pmu.flags & PMU_FL_PEBS_ALL) + status &= ~cpuc->pebs_enabled; + else + status &= ~(cpuc->pebs_enabled & PEBS_COUNTER_MASK); /* * PEBS overflow sets bit 62 in the global status register diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index 9fd9cb1..595b96a 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -903,10 +903,16 @@ static inline void pebs_update_threshold(struct cpu_hw_events *cpuc) { struct debug_store *ds = cpuc->ds; u64 threshold; + int reserved; + + if (x86_pmu.flags & PMU_FL_PEBS_ALL) + reserved = x86_pmu.max_pebs_events + x86_pmu.num_counters_fixed; + else + reserved = x86_pmu.max_pebs_events; if (cpuc->n_pebs == cpuc->n_large_pebs) { threshold = ds->pebs_absolute_maximum - - x86_pmu.max_pebs_events * x86_pmu.pebs_record_size; + reserved * x86_pmu.pebs_record_size; } else { threshold = ds->pebs_buffer_base + x86_pmu.pebs_record_size; } @@ -970,7 +976,11 @@ void intel_pmu_pebs_enable(struct perf_event *event) * This must be done in pmu::start(), because PERF_EVENT_IOC_PERIOD. */ if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) { - ds->pebs_event_reset[hwc->idx] = + unsigned int idx = hwc->idx; + + if (idx >= INTEL_PMC_IDX_FIXED) + idx = MAX_PEBS_EVENTS + (idx - INTEL_PMC_IDX_FIXED); + ds->pebs_event_reset[idx] = (u64)(-hwc->sample_period) & x86_pmu.cntval_mask; } else { ds->pebs_event_reset[hwc->idx] = 0; @@ -1488,9 +1498,10 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) struct debug_store *ds = cpuc->ds; struct perf_event *event; void *base, *at, *top; - short counts[MAX_PEBS_EVENTS] = {}; - short error[MAX_PEBS_EVENTS] = {}; - int bit, i; + short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {}; + short error[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {}; + int bit, i, size; + u64 mask; if (!x86_pmu.pebs_active) return; @@ -1500,6 +1511,13 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) ds->pebs_index = ds->pebs_buffer_base; + mask = (1ULL << x86_pmu.max_pebs_events) - 1; + size = x86_pmu.max_pebs_events; + if (x86_pmu.flags & PMU_FL_PEBS_ALL) { + mask |= ((1ULL << x86_pmu.num_counters_fixed) - 1) << INTEL_PMC_IDX_FIXED; + size = INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed; + } + if (unlikely(base >= top)) { /* * The drain_pebs() could be called twice in a short period @@ -1509,7 +1527,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) * update the event->count for this case. */ for_each_set_bit(bit, (unsigned long *)&cpuc->pebs_enabled, - x86_pmu.max_pebs_events) { + size) { event = cpuc->events[bit]; if (event->hw.flags & PERF_X86_EVENT_AUTO_RELOAD) intel_pmu_save_and_restart_reload(event, 0); @@ -1522,12 +1540,12 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) u64 pebs_status; pebs_status = p->status & cpuc->pebs_enabled; - pebs_status &= (1ULL << x86_pmu.max_pebs_events) - 1; + pebs_status &= mask; /* PEBS v3 has more accurate status bits */ if (x86_pmu.intel_cap.pebs_format >= 3) { for_each_set_bit(bit, (unsigned long *)&pebs_status, - x86_pmu.max_pebs_events) + size) counts[bit]++; continue; @@ -1575,7 +1593,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) counts[bit]++; } - for (bit = 0; bit < x86_pmu.max_pebs_events; bit++) { + for (bit = 0; bit < size; bit++) { if ((counts[bit] == 0) && (error[bit] == 0)) continue; diff --git a/arch/x86/include/asm/intel_ds.h b/arch/x86/include/asm/intel_ds.h index 62a9f49..ae26df1 100644 --- a/arch/x86/include/asm/intel_ds.h +++ b/arch/x86/include/asm/intel_ds.h @@ -8,6 +8,7 @@ /* The maximal number of PEBS events: */ #define MAX_PEBS_EVENTS 8 +#define MAX_FIXED_PEBS_EVENTS 3 /* * A debug store configuration. @@ -23,7 +24,7 @@ struct debug_store { u64 pebs_index; u64 pebs_absolute_maximum; u64 pebs_interrupt_threshold; - u64 pebs_event_reset[MAX_PEBS_EVENTS]; + u64 pebs_event_reset[MAX_PEBS_EVENTS + MAX_FIXED_PEBS_EVENTS]; } __aligned(PAGE_SIZE); DECLARE_PER_CPU_PAGE_ALIGNED(struct debug_store, cpu_debug_store); -- 2.7.4