[PATCH v5 14/26] perf stat: Add default hybrid events

Jin Yao
2021-04-23T05:37:40Z

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':

24,043.99 msec cpu-clock # 23.991 CPUs utilized
139 context-switches # 5.781 /sec
25 cpu-migrations # 1.040 /sec
6 page-faults # 0.250 /sec
10,381,751 cpu_core/cycles/ # 431.782 K/sec
1,264,216 cpu_atom/cycles/ # 52.579 K/sec
3,406,958 cpu_core/instructions/ # 141.697 K/sec
414,588 cpu_atom/instructions/ # 17.243 K/sec
705,149 cpu_core/branches/ # 29.327 K/sec
82,358 cpu_atom/branches/ # 3.425 K/sec
40,821 cpu_core/branch-misses/ # 1.698 K/sec
9,086 cpu_atom/branch-misses/ # 377.891 /sec

1.002228863 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>
---
v5:
- Do the same way like when topdown calls parse events for checking
result and displayt the error.

v4:
- No change.

tools/perf/builtin-stat.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 1255af4751c2..3ab4069ff8f0 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1626,6 +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 },
};

/*
@@ -1863,6 +1869,28 @@ static int add_default_attributes(void)
}

if (!evsel_list->core.nr_entries) {
+ if (perf_pmu__has_hybrid()) {
+ const char *hybrid_str = "cycles,instructions,branches,branch-misses";
+
+ if (target__has_cpu(&target))
+ default_sw_attrs[0].config = PERF_COUNT_SW_CPU_CLOCK;
+
+ if (evlist__add_default_attrs(evsel_list,
+ default_sw_attrs) < 0) {
+ return -1;
+ }
+
+ err = parse_events(evsel_list, hybrid_str, &errinfo);
+ if (err) {
+ fprintf(stderr,
+ "Cannot set up hybrid events %s: %d\n",
+ hybrid_str, err);
+ parse_events_print_error(&errinfo, hybrid_str);
+ return -1;
+ }
+ return err;
+ }
+
if (target__has_cpu(&target))
default_attrs0[0].config = PERF_COUNT_SW_CPU_CLOCK;

--
2.17.1