@@ -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.
@@ -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 &&
@@ -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);
@@ -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);
@@ -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);
@@ -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);
}
}
@@ -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;
}
@@ -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
@@ -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