[PATCH v8 01/10] perf record --off-cpu: Add --off-cpu-thresh option
From: Howard Chu
Date: Tue Nov 12 2024 - 19:28:44 EST
Specify the threshold for dumping offcpu samples with --off-cpu-thresh,
the unit is us (microsecond). Default value is 500000us (500ms, 0.5s).
Suggested-by: Ian Rogers <irogers@xxxxxxxxxx>
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>
Signed-off-by: Howard Chu <howardchu95@xxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241108204137.2444151-2-howardchu95@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 26 ++++++++++++++++++++++++++
tools/perf/util/off_cpu.h | 1 +
tools/perf/util/record.h | 1 +
3 files changed, 28 insertions(+)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index f83252472921..c069000efe5c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -3149,6 +3149,28 @@ static int record__parse_mmap_pages(const struct option *opt,
return ret;
}
+static int record__parse_off_cpu_thresh(const struct option *opt,
+ const char *str,
+ int unset __maybe_unused)
+{
+ struct record_opts *opts = opt->value;
+ char *endptr;
+ u64 off_cpu_thresh_us;
+
+ if (!str)
+ return -EINVAL;
+
+ off_cpu_thresh_us = strtoull(str, &endptr, 10);
+
+ /* threshold isn't string "0", yet strtoull() returns 0, parsing failed */
+ if (*endptr || (off_cpu_thresh_us == 0 && strcmp(str, "0")))
+ return -EINVAL;
+ else
+ opts->off_cpu_thresh_us = off_cpu_thresh_us;
+
+ return 0;
+}
+
void __weak arch__add_leaf_frame_record_opts(struct record_opts *opts __maybe_unused)
{
}
@@ -3342,6 +3364,7 @@ static struct record record = {
.ctl_fd = -1,
.ctl_fd_ack = -1,
.synth = PERF_SYNTH_ALL,
+ .off_cpu_thresh_us = OFFCPU_THRESH,
},
};
@@ -3564,6 +3587,9 @@ static struct option __record_options[] = {
OPT_BOOLEAN(0, "off-cpu", &record.off_cpu, "Enable off-cpu analysis"),
OPT_STRING(0, "setup-filter", &record.filter_action, "pin|unpin",
"BPF filter action"),
+ OPT_CALLBACK(0, "off-cpu-thresh", &record.opts, "us",
+ "Dump off-cpu samples if off-cpu time reaches this threshold. The unit is microsecond (default: 500000)",
+ record__parse_off_cpu_thresh),
OPT_END()
};
diff --git a/tools/perf/util/off_cpu.h b/tools/perf/util/off_cpu.h
index 2dd67c60f211..c6edc0f7c40d 100644
--- a/tools/perf/util/off_cpu.h
+++ b/tools/perf/util/off_cpu.h
@@ -16,6 +16,7 @@ struct record_opts;
PERF_SAMPLE_PERIOD | PERF_SAMPLE_CALLCHAIN | \
PERF_SAMPLE_CGROUP)
+#define OFFCPU_THRESH 500000ull
#ifdef HAVE_BPF_SKEL
int off_cpu_prepare(struct evlist *evlist, struct target *target,
diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h
index a6566134e09e..2ca74add26c0 100644
--- a/tools/perf/util/record.h
+++ b/tools/perf/util/record.h
@@ -79,6 +79,7 @@ struct record_opts {
int synth;
int threads_spec;
const char *threads_user_spec;
+ u64 off_cpu_thresh_us;
};
extern const char * const *record_usage;
--
2.43.0