diff options
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 13 | ||||
| -rw-r--r-- | tools/perf/builtin-record.c | 41 |
2 files changed, 50 insertions, 4 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 6e8b4649307c..561ef55743e2 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -556,6 +556,19 @@ overhead. You can still switch them on with: --switch-output --no-no-buildid --no-no-buildid-cache +--switch-output-event:: +Events that will cause the switch of the perf.data file, auto-selecting +--switch-output=signal, the results are similar as internally the side band +thread will also send a SIGUSR2 to the main one. + +Uses the same syntax as --event, it will just not be recorded, serving only to +switch the perf.data file as soon as the --switch-output event is processed by +a separate sideband thread. + +This sideband thread is also used to other purposes, like processing the +PERF_RECORD_BPF_EVENT records as they happen, asking the kernel for extra BPF +information, etc. + --switch-max-files=N:: When rotating perf.data with --switch-output, only keep N files. diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 5b6a1d23efe5..bb5b4d2fc32b 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -88,7 +88,9 @@ struct record { struct evlist *evlist; struct perf_session *session; struct evlist *sb_evlist; + pthread_t thread_id; int realtime_prio; + bool switch_output_event_set; bool no_buildid; bool no_buildid_set; bool no_buildid_cache; @@ -1437,6 +1439,13 @@ out: return err; } +static int record__process_signal_event(union perf_event *event __maybe_unused, void *data) +{ + struct record *rec = data; + pthread_kill(rec->thread_id, SIGUSR2); + return 0; +} + static int __cmd_record(struct record *rec, int argc, const char **argv) { int err; @@ -1581,12 +1590,24 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) goto out_child; } - if (!opts->no_bpf_event) { - rec->sb_evlist = evlist__new(); + if (rec->sb_evlist != NULL) { + /* + * We get here if --switch-output-event populated the + * sb_evlist, so associate a callback that will send a SIGUSR2 + * to the main thread. + */ + evlist__set_cb(rec->sb_evlist, record__process_signal_event, rec); + rec->thread_id = pthread_self(); + } + if (!opts->no_bpf_event) { if (rec->sb_evlist == NULL) { - pr_err("Couldn't create side band evlist.\n."); - goto out_child; + rec->sb_evlist = evlist__new(); + + if (rec->sb_evlist == NULL) { + pr_err("Couldn't create side band evlist.\n."); + goto out_child; + } } if (evlist__add_bpf_sb_event(rec->sb_evlist, &session->header.env)) { @@ -2180,10 +2201,19 @@ static int switch_output_setup(struct record *rec) }; unsigned long val; + /* + * If we're using --switch-output-events, then we imply its + * --switch-output=signal, as we'll send a SIGUSR2 from the side band + * thread to its parent. + */ + if (rec->switch_output_event_set) + goto do_signal; + if (!s->set) return 0; if (!strcmp(s->str, "signal")) { +do_signal: s->signal = true; pr_debug("switch-output with SIGUSR2 signal\n"); goto enabled; @@ -2441,6 +2471,9 @@ static struct option __record_options[] = { &record.switch_output.set, "signal or size[BKMG] or time[smhd]", "Switch output when receiving SIGUSR2 (signal) or cross a size or time threshold", "signal"), + OPT_CALLBACK_SET(0, "switch-output-event", &record.sb_evlist, &record.switch_output_event_set, "switch output event", + "switch output event selector. use 'perf list' to list available events", + parse_events_option_new_evlist), OPT_INTEGER(0, "switch-max-files", &record.switch_output.num_files, "Limit number of switch output generated files"), OPT_BOOLEAN(0, "dry-run", &dry_run, |