diff options
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 1 | ||||
| -rw-r--r-- | arch/x86/events/intel/lbr.c | 3 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 12 | ||||
| -rw-r--r-- | include/uapi/linux/perf_event.h | 8 | ||||
| -rw-r--r-- | kernel/events/core.c | 10 |
5 files changed, 33 insertions, 1 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 3086055bf681..3dcfecf858f3 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -518,6 +518,7 @@ static void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events * } } cpuhw->bhrb_stack.nr = u_index; + cpuhw->bhrb_stack.hw_idx = -1ULL; return; } diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 534c76606049..7639e2097101 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -585,6 +585,7 @@ static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc) cpuc->lbr_entries[i].reserved = 0; } cpuc->lbr_stack.nr = i; + cpuc->lbr_stack.hw_idx = -1ULL; } /* @@ -680,6 +681,7 @@ static void intel_pmu_lbr_read_64(struct cpu_hw_events *cpuc) out++; } cpuc->lbr_stack.nr = out; + cpuc->lbr_stack.hw_idx = -1ULL; } void intel_pmu_lbr_read(void) @@ -1120,6 +1122,7 @@ void intel_pmu_store_pebs_lbrs(struct pebs_lbr *lbr) int i; cpuc->lbr_stack.nr = x86_pmu.lbr_nr; + cpuc->lbr_stack.hw_idx = -1ULL; for (i = 0; i < x86_pmu.lbr_nr; i++) { u64 info = lbr->lbr[i].info; struct perf_branch_entry *e = &cpuc->lbr_entries[i]; diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 547773f5894e..68e21e828893 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -93,14 +93,26 @@ struct perf_raw_record { /* * branch stack layout: * nr: number of taken branches stored in entries[] + * hw_idx: The low level index of raw branch records + * for the most recent branch. + * -1ULL means invalid/unknown. * * Note that nr can vary from sample to sample * branches (to, from) are stored from most recent * to least recent, i.e., entries[0] contains the most * recent branch. + * The entries[] is an abstraction of raw branch records, + * which may not be stored in age order in HW, e.g. Intel LBR. + * The hw_idx is to expose the low level index of raw + * branch record for the most recent branch aka entries[0]. + * The hw_idx index is between -1 (unknown) and max depth, + * which can be retrieved in /sys/devices/cpu/caps/branches. + * For the architectures whose raw branch records are + * already stored in age order, the hw_idx should be 0. */ struct perf_branch_stack { __u64 nr; + __u64 hw_idx; struct perf_branch_entry entries[0]; }; diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 377d794d3105..397cfd65b3fe 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -181,6 +181,8 @@ enum perf_branch_sample_type_shift { PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT = 16, /* save branch type */ + PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT = 17, /* save low level index of raw branch records */ + PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */ }; @@ -208,6 +210,8 @@ enum perf_branch_sample_type { PERF_SAMPLE_BRANCH_TYPE_SAVE = 1U << PERF_SAMPLE_BRANCH_TYPE_SAVE_SHIFT, + PERF_SAMPLE_BRANCH_HW_INDEX = 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT, + PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT, }; @@ -853,7 +857,9 @@ enum perf_event_type { * char data[size];}&& PERF_SAMPLE_RAW * * { u64 nr; - * { u64 from, to, flags } lbr[nr];} && PERF_SAMPLE_BRANCH_STACK + * { u64 hw_idx; } && PERF_SAMPLE_BRANCH_HW_INDEX + * { u64 from, to, flags } lbr[nr]; + * } && PERF_SAMPLE_BRANCH_STACK * * { u64 abi; # enum perf_sample_regs_abi * u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_USER diff --git a/kernel/events/core.c b/kernel/events/core.c index e453589da97c..3f1f77de7247 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6555,6 +6555,11 @@ static void perf_output_read(struct perf_output_handle *handle, perf_output_read_one(handle, event, enabled, running); } +static inline bool perf_sample_save_hw_index(struct perf_event *event) +{ + return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX; +} + void perf_output_sample(struct perf_output_handle *handle, struct perf_event_header *header, struct perf_sample_data *data, @@ -6643,6 +6648,8 @@ void perf_output_sample(struct perf_output_handle *handle, * sizeof(struct perf_branch_entry); perf_output_put(handle, data->br_stack->nr); + if (perf_sample_save_hw_index(event)) + perf_output_put(handle, data->br_stack->hw_idx); perf_output_copy(handle, data->br_stack->entries, size); } else { /* @@ -6836,6 +6843,9 @@ void perf_prepare_sample(struct perf_event_header *header, if (sample_type & PERF_SAMPLE_BRANCH_STACK) { int size = sizeof(u64); /* nr */ if (data->br_stack) { + if (perf_sample_save_hw_index(event)) + size += sizeof(u64); + size += data->br_stack->nr * sizeof(struct perf_branch_entry); } |