Use reftime event for initial correlation of perf_clock to time-of-day. Add timekeeping trace events to event list to capture jumps in time-of-day.
Signed-off-by: David Ahern <[email protected]> --- tools/perf/Documentation/perf-record.txt | 3 + tools/perf/builtin-record.c | 102 +++++++++++++++++++++++++++++- 2 files changed, 104 insertions(+), 1 deletions(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 5a520f8..e4c87ba 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -148,6 +148,9 @@ an empty cgroup (monitor all the time) using, e.g., -G foo,,bar. Cgroups must ha corresponding events, i.e., they always refer to events defined earlier on the command line. +--tod:: +Collect data for displaying time-of-day strings when printing events. + SEE ALSO -------- linkperf:perf-stat[1], linkperf:perf-list[1] diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 8e2c857..4f8d5f2 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -32,6 +32,9 @@ #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) +#define TRACE_TOD_SUBSYSTEM "timekeeping" +#define TRACE_TOD_SUBSYSTEM_LEN 11 + enum write_mode_t { WRITE_FORCE, WRITE_APPEND @@ -65,6 +68,8 @@ static bool sample_address = false; static bool sample_time = false; static bool no_buildid = false; static bool no_buildid_cache = false; +static bool want_tod = false; +static u64 tod_sample_type; static struct perf_evlist *evsel_list; static long samples = 0; @@ -215,6 +220,9 @@ static void config_attr(struct perf_evsel *evsel, struct perf_evlist *evlist) attr->sample_type |= PERF_SAMPLE_CPU; } + if (want_tod) + attr->sample_type |= tod_sample_type; + if (nodelay) { attr->watermark = 0; attr->wakeup_events = 1; @@ -248,6 +256,86 @@ static bool perf_evlist__equal(struct perf_evlist *evlist, return true; } +static int perf_event__synthesize_reftime(perf_event__handler_t process) +{ + union perf_event ev; + struct timespec tp; + + memset(&ev, 0, sizeof(ev)); + + if (gettimeofday(&ev.reftime.tv, NULL) != 0) { + error("gettimeofday failed.\n"); + return -1; + } + if (clock_gettime(CLOCK_MONOTONIC, &tp) != 0) { + error("clock_gettime(CLOCK_MONOTONIC) failed.\n"); + return -1; + } + ev.reftime.nsec = (u64) tp.tv_sec * NSEC_PER_SEC + (u64) tp.tv_nsec; + + ev.header.type = PERF_RECORD_REFTIME; + ev.header.size = sizeof(ev.reftime); + + return process(&ev, NULL, session); +} + +static int add_timeofday_events(void) +{ + int rc, i, len; + struct perf_event_attr attr; + struct perf_evsel *evsel; + + /* events that modify xtime */ + const char *tod_events[] = {"settimeofday", + "timekeeping_inject_offset", + "timekeeping_inject_sleeptime", + NULL}; + + i = 0; + rc = -1; + while (tod_events[i]) { + memset(&attr, 0, sizeof(attr)); + len = strlen(tod_events[i]); + + if (parse_single_tracepoint_event(TRACE_TOD_SUBSYSTEM, + tod_events[i], len, &attr, NULL) == EVT_FAILED) { + error("Failed to parse event %s\n", tod_events[i]); + goto out; + } + + evsel = perf_evsel__new(&attr, evsel_list->nr_entries); + if (evsel == NULL) + return -1; + + perf_evlist__add(evsel_list, evsel); + + /* +2 for ':' delimiter and string terminator */ + evsel->name = calloc(TRACE_TOD_SUBSYSTEM_LEN + len + 2, 1); + if (!evsel->name) + return -1; + + sprintf(evsel->name, "timekeeping:%s", tod_events[i]); + + tod_sample_type |= attr.sample_type; + + ++i; + } + + /* + * right now sample_type for all samples needs to be the same. + * tracepoints are collected at sample period 1 and hence do not + * request the period with the sample. However, default for record + * is cycles at a frequency. So, until this sample_type mess is + * fixed.... + */ + if (freq) + tod_sample_type |= PERF_SAMPLE_PERIOD; + + rc = 0; +out: + return rc; +} + static void open_counters(struct perf_evlist *evlist) { struct perf_evsel *pos; @@ -289,7 +377,8 @@ try_again: * Old kernel, no attr->sample_id_type_all field */ sample_id_all_avail = false; - if (!sample_time && !raw_samples && !time_needed) + if (!sample_time && !raw_samples && + !time_needed && !want_tod) attr->sample_type &= ~PERF_SAMPLE_TIME; goto retry_sample_id; @@ -629,6 +718,11 @@ static int __cmd_record(int argc, const char **argv) } } + if (want_tod && + (perf_event__synthesize_reftime(process_synthesized_event) != 0)) + error("Failed to create reftime event. " + "Cannot generate wall-clock timestamps\n"); + machine = perf_session__find_host_machine(session); if (!machine) { pr_err("Couldn't find native kernel information.\n"); @@ -787,6 +881,8 @@ const struct option record_options[] = { OPT_CALLBACK('G', "cgroup", &evsel_list, "name", "monitor event in cgroup name only", parse_cgroups), + OPT_BOOLEAN(0, "tod", &want_tod, + "Collect data for time-of-day strings"), OPT_END() }; @@ -842,6 +938,10 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) goto out_symbol_exit; } + if (want_tod && (add_timeofday_events() != 0)) + error("Failed to add timekeeping events to event list.\n" + "Cannot generate wall-clock timestamps\n"); + if (target_pid != -1) target_tid = target_pid; -- 1.7.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
