diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2025-02-13 10:08:19 +0100 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2025-02-18 14:04:32 -0800 |
| commit | 2570c02c3a5a8b27e2e14cd205ccb796e01f3308 (patch) | |
| tree | efb670724e91bc73a86b8c9af16ffd3a2f032b18 /tools/perf/builtin-record.c | |
| parent | ee1cffbe24e7dc129c737a5f433b35e2ce0bdd78 (diff) | |
perf report: Add --latency flag
Add record/report --latency flag that allows to capture and show
latency-centric profiles rather than the default CPU-consumption-centric
profiles. For latency profiles record captures context switch events,
and report shows Latency as the first column.
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Link: https://lore.kernel.org/r/e9640464bcbc47dde2cb557003f421052ebc9eec.1739437531.git.dvyukov@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'tools/perf/builtin-record.c')
| -rw-r--r-- | tools/perf/builtin-record.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index cda7e6a7b45d..9af3f21fd015 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -161,6 +161,7 @@ struct record { struct evlist *sb_evlist; pthread_t thread_id; int realtime_prio; + bool latency; bool switch_output_event_set; bool no_buildid; bool no_buildid_set; @@ -3373,6 +3374,9 @@ static struct option __record_options[] = { parse_events_option), OPT_CALLBACK(0, "filter", &record.evlist, "filter", "event filter", parse_filter), + OPT_BOOLEAN(0, "latency", &record.latency, + "Enable data collection for latency profiling.\n" + "\t\t\t Use perf report --latency for latency-centric profile."), OPT_CALLBACK_NOOPT(0, "exclude-perf", &record.evlist, NULL, "don't record events from perf itself", exclude_perf), @@ -4019,6 +4023,22 @@ int cmd_record(int argc, const char **argv) } + if (record.latency) { + /* + * There is no fundamental reason why latency profiling + * can't work for system-wide mode, but exact semantics + * and details are to be defined. + * See the following thread for details: + * https://lore.kernel.org/all/Z4XDJyvjiie3howF@google.com/ + */ + if (record.opts.target.system_wide) { + pr_err("Failed: latency profiling is not supported with system-wide collection.\n"); + err = -EINVAL; + goto out_opts; + } + record.opts.record_switch_events = true; + } + if (rec->buildid_mmap) { if (!perf_can_record_build_id()) { pr_err("Failed: no support to record build id in mmap events, update your kernel.\n"); |