This is a note to let you know that I've just added the patch titled
perf stat: Fix counting when initial delay configured
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-stat-fix-counting-when-initial-delay-configured.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 67e3ba97975f46659bfb079cb64a269a675c2328
Author: Changbin Du <changbin.du@xxxxxxxxxx>
Date: Thu Mar 2 11:11:44 2023 +0800
perf stat: Fix counting when initial delay configured
[ Upstream commit 25f69c69bc3ca8c781a94473f28d443d745768e3 ]
When creating counters with initial delay configured, the enable_on_exec
field is not set. So we need to enable the counters later. The problem
is, when a workload is specified the target__none() is true. So we also
need to check stat_config.initial_delay.
In this change, we add a new field 'initial_delay' for struct target
which could be shared by other subcommands. And define
target__enable_on_exec() which returns whether enable_on_exec should be
set on normal cases.
Before this fix the event is not counted:
$ ./perf stat -e instructions -D 100 sleep 2
Events disabled
Events enabled
Performance counter stats for 'sleep 2':
<not counted> instructions
1.901661124 seconds time elapsed
0.001602000 seconds user
0.000000000 seconds sys
After fix it works:
$ ./perf stat -e instructions -D 100 sleep 2
Events disabled
Events enabled
Performance counter stats for 'sleep 2':
404,214 instructions
1.901743475 seconds time elapsed
0.001617000 seconds user
0.000000000 seconds sys
Fixes: c587e77e100fa40e ("perf stat: Do not delay the workload with --delay")
Signed-off-by: Changbin Du <changbin.du@xxxxxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Hui Wang <hw.huiwang@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230302031146.2801588-2-changbin.du@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index aad65c95c3711..0b709e3ead2ac 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -558,12 +558,7 @@ static int enable_counters(void)
return err;
}
- /*
- * We need to enable counters only if:
- * - we don't have tracee (attaching to task or cpu)
- * - we have initial delay configured
- */
- if (!target__none(&target)) {
+ if (!target__enable_on_exec(&target)) {
if (!all_counters_use_bpf)
evlist__enable(evsel_list);
}
@@ -941,7 +936,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
return err;
}
- if (stat_config.initial_delay) {
+ if (target.initial_delay) {
pr_info(EVLIST_DISABLED_MSG);
} else {
err = enable_counters();
@@ -953,8 +948,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
if (forks)
evlist__start_workload(evsel_list);
- if (stat_config.initial_delay > 0) {
- usleep(stat_config.initial_delay * USEC_PER_MSEC);
+ if (target.initial_delay > 0) {
+ usleep(target.initial_delay * USEC_PER_MSEC);
err = enable_counters();
if (err)
return -1;
@@ -1244,7 +1239,7 @@ static struct option stat_options[] = {
"aggregate counts per thread", AGGR_THREAD),
OPT_SET_UINT(0, "per-node", &stat_config.aggr_mode,
"aggregate counts per numa node", AGGR_NODE),
- OPT_INTEGER('D', "delay", &stat_config.initial_delay,
+ OPT_INTEGER('D', "delay", &target.initial_delay,
"ms to wait before starting measurement after program start (-1: start with events disabled)"),
OPT_CALLBACK_NOOPT(0, "metric-only", &stat_config.metric_only, NULL,
"Only print computed metrics. No raw values", enable_metric_only),
diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 09ea334586f23..5a0b3db1cab11 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -576,11 +576,7 @@ int create_perf_stat_counter(struct evsel *evsel,
if (evsel__is_group_leader(evsel)) {
attr->disabled = 1;
- /*
- * In case of initial_delay we enable tracee
- * events manually.
- */
- if (target__none(target) && !config->initial_delay)
+ if (target__enable_on_exec(target))
attr->enable_on_exec = 1;
}
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 32c8527de3478..977616cf69e46 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -137,7 +137,6 @@ struct perf_stat_config {
FILE *output;
unsigned int interval;
unsigned int timeout;
- int initial_delay;
unsigned int unit_width;
unsigned int metric_only_len;
int times;
diff --git a/tools/perf/util/target.h b/tools/perf/util/target.h
index daec6cba500d4..880f1af7f6ad6 100644
--- a/tools/perf/util/target.h
+++ b/tools/perf/util/target.h
@@ -18,6 +18,7 @@ struct target {
bool per_thread;
bool use_bpf;
bool hybrid;
+ int initial_delay;
const char *attr_map;
};
@@ -72,6 +73,17 @@ static inline bool target__none(struct target *target)
return !target__has_task(target) && !target__has_cpu(target);
}
+static inline bool target__enable_on_exec(struct target *target)
+{
+ /*
+ * Normally enable_on_exec should be set if:
+ * 1) The tracee process is forked (not attaching to existed task or cpu).
+ * 2) And initial_delay is not configured.
+ * Otherwise, we enable tracee events manually.
+ */
+ return target__none(target) && !target->initial_delay;
+}
+
static inline bool target__has_per_thread(struct target *target)
{
return target->system_wide && target->per_thread;
