Re: [PATCH v3 3/3] perf tools: Enable on a list of CPUs for hybrid
From: Jin, Yao
Date: Tue Jul 20 2021 - 03:08:04 EST
Hi Jiri,
On 7/20/2021 3:36 AM, Jiri Olsa wrote:
On Mon, Jul 12, 2021 at 03:12:35PM +0800, Jin Yao wrote:
The perf-record and perf-stat have supported the option '-C/--cpus'
to count or collect only on the list of CPUs provided. This option
needs to be supported for hybrid as well.
For hybrid support, it needs to check that the CPUs are available on
hybrid PMU. One example for AlderLake, cpu0-7 is 'cpu_core', cpu8-11
is 'cpu_atom'.
Before:
# perf stat -e cpu_core/cycles/ -C11 -- sleep 1
Performance counter stats for 'CPU(s) 11':
<not supported> cpu_core/cycles/
1.006179431 seconds time elapsed
The perf-stat silently returned "<not supported>" without any helpful
information. It should error out that cpu11 was not 'cpu_core'.
After:
# perf stat -e cpu_core/cycles/ -C11 -- sleep 1
WARNING: 11 isn't a 'cpu_core', please use a CPU list in the 'cpu_core' range (0-7)
failed to use cpu list 11
We also need to support the events without pmu prefix specified.
# perf stat -e cycles -C11 -- sleep 1
WARNING: 11 isn't a 'cpu_core', please use a CPU list in the 'cpu_core' range (0-7)
Performance counter stats for 'CPU(s) 11':
1,067,373 cpu_atom/cycles/
1.005544738 seconds time elapsed
The perf tool creates two cycles events automatically, cpu_core/cycles/ and
cpu_atom/cycles/. It checks that cpu11 is not 'cpu_core', then shows a warning
for cpu_core/cycles/ and only count the cpu_atom/cycles/.
If part of cpus are 'cpu_core' and part of cpus are 'cpu_atom', the example,
# perf stat -e cycles -C0,11 -- sleep 1
WARNING: use 0 in 'cpu_core' for 'cycles', skip other cpus in list.
WARNING: use 11 in 'cpu_atom' for 'cycles', skip other cpus in list.
Performance counter stats for 'CPU(s) 0,11':
1,914,704 cpu_core/cycles/
2,036,983 cpu_atom/cycles/
1.005815641 seconds time elapsed
It now automatically selects cpu0 for cpu_core/cycles/, selects cpu11 for
cpu_atom/cycles/, and output with some warnings.
Some more complex examples,
# perf stat -e cycles,instructions -C0,11 -- sleep 1
WARNING: use 0 in 'cpu_core' for 'cycles', skip other cpus in list.
WARNING: use 11 in 'cpu_atom' for 'cycles', skip other cpus in list.
WARNING: use 0 in 'cpu_core' for 'instructions', skip other cpus in list.
WARNING: use 11 in 'cpu_atom' for 'instructions', skip other cpus in list.
Performance counter stats for 'CPU(s) 0,11':
2,780,387 cpu_core/cycles/
1,583,432 cpu_atom/cycles/
3,957,277 cpu_core/instructions/
1,167,089 cpu_atom/instructions/
1.006005124 seconds time elapsed
# perf stat -e cycles,cpu_atom/instructions/ -C0,11 -- sleep 1
WARNING: use 0 in 'cpu_core' for 'cycles', skip other cpus in list.
WARNING: use 11 in 'cpu_atom' for 'cycles', skip other cpus in list.
WARNING: use 11 in 'cpu_atom' for 'cpu_atom/instructions/', skip other cpus in list.
Performance counter stats for 'CPU(s) 0,11':
3,290,301 cpu_core/cycles/
1,953,073 cpu_atom/cycles/
1,407,869 cpu_atom/instructions/
1.006260912 seconds time elapsed
Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
v3:
- Rebase to perf/core.
- No functional change.
v2:
- Automatically map to hybrid pmu.
tools/perf/builtin-record.c | 7 ++++
tools/perf/builtin-stat.c | 6 +++
tools/perf/util/evlist-hybrid.c | 65 +++++++++++++++++++++++++++++++++
tools/perf/util/evlist-hybrid.h | 1 +
tools/perf/util/evlist.c | 1 +
tools/perf/util/pmu.c | 35 ++++++++++++++++++
tools/perf/util/pmu.h | 4 ++
7 files changed, 119 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 671a21c9ee4d..9518b028b850 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2884,6 +2884,13 @@ int cmd_record(int argc, const char **argv)
/* Enable ignoring missing threads when -u/-p option is defined. */
rec->opts.ignore_missing_thread = rec->opts.target.uid != UINT_MAX || rec->opts.target.pid;
+ if (evlist__use_cpu_list(rec->evlist, rec->opts.target.cpu_list)) {
+ pr_err("failed to use cpu list %s\n",
+ rec->opts.target.cpu_list);
+ goto out;
+ }
+
+ rec->opts.target.hybrid = perf_pmu__has_hybrid();
err = -ENOMEM;
if (evlist__create_maps(rec->evlist, &rec->opts.target) < 0)
usage_with_options(record_usage, record_options);
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index d25cb8088e8c..f7067587008f 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -2430,6 +2430,12 @@ int cmd_stat(int argc, const char **argv)
if ((stat_config.aggr_mode == AGGR_THREAD) && (target.system_wide))
target.per_thread = true;
+ if (evlist__use_cpu_list(evsel_list, target.cpu_list)) {
+ pr_err("failed to use cpu list %s\n", target.cpu_list);
+ goto out;
+ }
+
+ target.hybrid = perf_pmu__has_hybrid();
if (evlist__create_maps(evsel_list, &target) < 0) {
if (target__has_task(&target)) {
pr_err("Problems finding threads of monitor\n");
diff --git a/tools/perf/util/evlist-hybrid.c b/tools/perf/util/evlist-hybrid.c
index db3f5fbdebe1..13c9f3063dda 100644
--- a/tools/perf/util/evlist-hybrid.c
+++ b/tools/perf/util/evlist-hybrid.c
@@ -86,3 +86,68 @@ bool evlist__has_hybrid(struct evlist *evlist)
return false;
}
+
+int evlist__use_cpu_list(struct evlist *evlist, const char *cpu_list)
the name seems not to cover what it's doing, how about something
like evlist__fix_cpus or such
OK, evlist__fix_cpus() is better, use this name in v4.
+{
+ struct perf_cpu_map *cpus;
+ struct evsel *evsel, *tmp;
+ struct perf_pmu *pmu;
+ int ret, unmatched_count = 0, events_nr = 0;
+
+ if (!perf_pmu__has_hybrid() || !cpu_list)
+ return 0;
+
+ cpus = perf_cpu_map__new(cpu_list);
+ if (!cpus)
+ return -1;
+
+ evlist__for_each_entry_safe(evlist, tmp, evsel) {
+ struct perf_cpu_map *matched_cpus, *unmatched_cpus;
+ char buf1[128], buf2[128];
+
+ pmu = perf_pmu__find_hybrid_pmu(evsel->pmu_name);
+ if (!pmu)
+ continue;
+
+ ret = perf_pmu__cpus_match(pmu, cpus, &matched_cpus,
+ &unmatched_cpus);
+ if (ret)
+ goto out;
+
+ events_nr++;
+
+ if (matched_cpus->nr > 0 && (unmatched_cpus->nr > 0 ||
+ matched_cpus->nr < cpus->nr ||
+ matched_cpus->nr < pmu->cpus->nr)) {
+ perf_cpu_map__put(evsel->core.cpus);
+ perf_cpu_map__put(evsel->core.own_cpus);
+ evsel->core.cpus = perf_cpu_map__get(matched_cpus);
+ evsel->core.own_cpus = perf_cpu_map__get(matched_cpus);
I'm bit confused in here.. AFAIUI there's 2 evsel objects create
for hybrid 'cycles' ... should they have already proper cpus set?
For 'cycles', yes two evsels are created automatically. One is for atom CPU (e.g. 8-11), the other
is for core CPU (e.g. 0-7). In this example, these 2 evsels have already the cpus set.
While the 'cpus' here is just the user specified cpu list.
cpus = perf_cpu_map__new(cpu_list);
We need to check that the cpu in 'cpus' is available on hybrid pmu or not and adjust the
evsel->core.cpus according the matching results.
+
+ if (unmatched_cpus->nr > 0) {
+ cpu_map__snprint(matched_cpus, buf1, sizeof(buf1));
+ pr_warning("WARNING: use %s in '%s' for '%s', skip other cpus in list.\n",
+ buf1, pmu->name, evsel->name);
+ }
+ }
+
+ if (matched_cpus->nr == 0) {
+ evlist__remove(evlist, evsel);
+ evsel__delete(evsel);
+
+ cpu_map__snprint(cpus, buf1, sizeof(buf1));
+ cpu_map__snprint(pmu->cpus, buf2, sizeof(buf2));
+ pr_warning("WARNING: %s isn't a '%s', please use a CPU list in the '%s' range (%s)\n",
+ buf1, pmu->name, pmu->name, buf2);
+ unmatched_count++;
+ }
hum, should we rather fail in here?
perf stat -e cpu_core/cycles/,cpu_atom/instructions/ -C11
CPU11 is atom CPU so the evsel 'cpu_core/cycles/' is failed but cpu_atom/instructions/ is OK.
Don't we report the partially successful event?
Thanks
Jin Yao
jirka