diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps b/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps index 8757dcf41c0825..a5f506f7d4819e 100644 --- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps +++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-caps @@ -16,3 +16,9 @@ Description: Example output in powerpc: grep . /sys/bus/event_source/devices/cpu/caps/* /sys/bus/event_source/devices/cpu/caps/pmu_name:POWER9 + + The "branch_counter_nr" in the supported platform exposes the + maximum number of counters which can be shown in the u64 counters + of PERF_SAMPLE_BRANCH_COUNTERS, while the "branch_counter_width" + exposes the width of each counter. Both of them can be used by + the perf tool to parse the logged counters in each branch. diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 8c1f7def596e4a..3c14596bbfaf81 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -2313,7 +2313,7 @@ static void record_and_restart(struct perf_event *event, unsigned long val, struct cpu_hw_events *cpuhw; cpuhw = this_cpu_ptr(&cpu_hw_events); power_pmu_bhrb_read(event, cpuhw); - perf_sample_save_brstack(&data, event, &cpuhw->bhrb_stack); + perf_sample_save_brstack(&data, event, &cpuhw->bhrb_stack, NULL); } if (event->attr.sample_type & PERF_SAMPLE_DATA_SRC && diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index e24976593a298a..4ee6390b45c903 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -940,7 +940,7 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs) continue; if (has_branch_stack(event)) - perf_sample_save_brstack(&data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); if (perf_event_overflow(event, &data, regs)) x86_pmu_stop(event, 0); diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 40ad1425ffa24b..40c9af124128d6 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -1702,7 +1702,7 @@ int x86_pmu_handle_irq(struct pt_regs *regs) perf_sample_data_init(&data, 0, event->hw.last_period); if (has_branch_stack(event)) - perf_sample_save_brstack(&data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); if (perf_event_overflow(event, &data, regs)) x86_pmu_stop(event, 0); diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index a08f794a0e79ac..41a164764a848f 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3047,7 +3047,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) perf_sample_data_init(&data, 0, event->hw.last_period); if (has_branch_stack(event)) - perf_sample_save_brstack(&data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL); if (perf_event_overflow(event, &data, regs)) x86_pmu_stop(event, 0); diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index bf97ab904d40f7..cb3f329f8fa4fa 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1755,7 +1755,7 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event, setup_pebs_time(event, data, pebs->tsc); if (has_branch_stack(event)) - perf_sample_save_brstack(data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(data, event, &cpuc->lbr_stack, NULL); } static void adaptive_pebs_save_regs(struct pt_regs *regs, @@ -1912,7 +1912,7 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event, if (has_branch_stack(event)) { intel_pmu_store_pebs_lbrs(lbr); - perf_sample_save_brstack(data, event, &cpuc->lbr_stack); + perf_sample_save_brstack(data, event, &cpuc->lbr_stack, NULL); } } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 0367d748fae0e6..7897ef06602723 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1139,6 +1139,10 @@ static inline bool branch_sample_priv(const struct perf_event *event) return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_PRIV_SAVE; } +static inline bool branch_sample_counters(const struct perf_event *event) +{ + return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS; +} struct perf_sample_data { /* @@ -1173,6 +1177,7 @@ struct perf_sample_data { struct perf_callchain_entry *callchain; struct perf_raw_record *raw; struct perf_branch_stack *br_stack; + u64 *br_stack_cntr; union perf_sample_weight weight; union perf_mem_data_src data_src; u64 txn; @@ -1250,7 +1255,8 @@ static inline void perf_sample_save_raw_data(struct perf_sample_data *data, static inline void perf_sample_save_brstack(struct perf_sample_data *data, struct perf_event *event, - struct perf_branch_stack *brs) + struct perf_branch_stack *brs, + u64 *brs_cntr) { int size = sizeof(u64); /* nr */ @@ -1258,7 +1264,16 @@ static inline void perf_sample_save_brstack(struct perf_sample_data *data, size += sizeof(u64); size += brs->nr * sizeof(struct perf_branch_entry); + /* + * The extension space for counters is appended after the + * struct perf_branch_stack. It is used to store the occurrences + * of events of each branch. + */ + if (brs_cntr) + size += brs->nr * sizeof(u64); + data->br_stack = brs; + data->br_stack_cntr = brs_cntr; data->dyn_size += size; data->sample_flags |= PERF_SAMPLE_BRANCH_STACK; } diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 39c6a250dd1b92..4461f380425b73 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift { PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT = 18, /* save privilege mode */ + PERF_SAMPLE_BRANCH_COUNTERS_SHIFT = 19, /* save occurrences of events on a branch */ + PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */ }; @@ -235,6 +237,8 @@ enum perf_branch_sample_type { PERF_SAMPLE_BRANCH_PRIV_SAVE = 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT, + PERF_SAMPLE_BRANCH_COUNTERS = 1U << PERF_SAMPLE_BRANCH_COUNTERS_SHIFT, + PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT, }; @@ -982,6 +986,12 @@ enum perf_event_type { * { u64 nr; * { u64 hw_idx; } && PERF_SAMPLE_BRANCH_HW_INDEX * { u64 from, to, flags } lbr[nr]; + * # + * # The format of the counters is decided by the + * # "branch_counter_nr" and "branch_counter_width", + * # which are defined in the ABI. + * # + * { u64 counters; } cntr[nr] && PERF_SAMPLE_BRANCH_COUNTERS * } && PERF_SAMPLE_BRANCH_STACK * * { u64 abi; # enum perf_sample_regs_abi diff --git a/kernel/events/core.c b/kernel/events/core.c index 3eb26c2c6e655e..d27ffd80ed6785 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7341,6 +7341,14 @@ void perf_output_sample(struct perf_output_handle *handle, if (branch_sample_hw_index(event)) perf_output_put(handle, data->br_stack->hw_idx); perf_output_copy(handle, data->br_stack->entries, size); + /* + * Add the extension space which is appended + * right after the struct perf_branch_stack. + */ + if (data->br_stack_cntr) { + size = data->br_stack->nr * sizeof(u64); + perf_output_copy(handle, data->br_stack_cntr, size); + } } else { /* * we always store at least the value of nr