[PATCH v3 14/27] perf stat: Add default hybrid events

Jin Yao
2021-03-29T07:03:15Z

Previously if '-e' is not specified in perf stat, some software events
and hardware events are added to evlist by default.

Before:

# ./perf stat -a -- sleep 1

Performance counter stats for 'system wide':

24,044.40 msec cpu-clock # 23.946 CPUs utilized
99 context-switches # 4.117 /sec
24 cpu-migrations # 0.998 /sec
3 page-faults # 0.125 /sec
7,000,244 cycles # 0.000 GHz
2,955,024 instructions # 0.42 insn per cycle
608,941 branches # 25.326 K/sec
31,991 branch-misses # 5.25% of all branches

1.004106859 seconds time elapsed

Among the events, cycles, instructions, branches and branch-misses
are hardware events.

One hybrid platform, two hardware events are created for one
hardware event.

cpu_core/cycles/,
cpu_atom/cycles/,
cpu_core/instructions/,
cpu_atom/instructions/,
cpu_core/branches/,
cpu_atom/branches/,
cpu_core/branch-misses/,
cpu_atom/branch-misses/

These events would be added to evlist on hybrid platform.

Since parse_events() has been supported to create two hardware events
for one event on hybrid platform, so we just use parse_events(evlist,
"cycles,instructions,branches,branch-misses") to create the default
events and add them to evlist.

After:

# ./perf stat -a -- sleep 1

Performance counter stats for 'system wide':

24,048.60 msec task-clock # 23.947 CPUs utilized
438 context-switches # 18.213 /sec
24 cpu-migrations # 0.998 /sec
6 page-faults # 0.249 /sec
24,813,157 cpu_core/cycles/ # 1.032 M/sec
8,072,687 cpu_atom/cycles/ # 335.682 K/sec
20,731,286 cpu_core/instructions/ # 862.058 K/sec
3,737,203 cpu_atom/instructions/ # 155.402 K/sec
2,620,924 cpu_core/branches/ # 108.984 K/sec
381,186 cpu_atom/branches/ # 15.851 K/sec
93,248 cpu_core/branch-misses/ # 3.877 K/sec
36,515 cpu_atom/branch-misses/ # 1.518 K/sec

1.004235472 seconds time elapsed

We can see two events are created for one hardware event.

One TODO is, the shadow stats looks a bit different, now it's just
'M/sec'.

The perf_stat__update_shadow_stats and perf_stat__print_shadow_stats
need to be improved in future if we want to get the original shadow
stats.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
v3:
- No functional change.

tools/perf/builtin-stat.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7b2dfe21c5a8..33fda8f55f66 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1140,6 +1140,13 @@ static int parse_stat_cgroups(const struct option *opt,
return parse_cgroups(opt, str, unset);
}

+static int add_default_hybrid_events(struct evlist *evlist)
+{
+ struct parse_events_error err;
+
+ return parse_events(evlist, "cycles,instructions,branches,branch-misses", &err);
+}
+
static struct option stat_options[] = {
OPT_BOOLEAN('T', "transaction", &transaction_run,
"hardware transaction statistics"),
@@ -1619,6 +1626,12 @@ static int add_default_attributes(void)
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES },

+};
+ struct perf_event_attr default_sw_attrs[] = {
+ { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK },
+ { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES },
+ { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
+ { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS },
};

/*
@@ -1856,6 +1869,14 @@ static int add_default_attributes(void)
}

if (!evsel_list->core.nr_entries) {
+ if (perf_pmu__has_hybrid()) {
+ if (evlist__add_default_attrs(evsel_list,
+ default_sw_attrs) < 0) {
+ return -1;
+ }
+ return add_default_hybrid_events(evsel_list);
+ }
+
if (target__has_cpu(&target))
default_attrs0[0].config = PERF_COUNT_SW_CPU_CLOCK;

--
2.17.1