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Date: Tue, 7 Jun 2011 17:56:04 -0600
From: David Ahern <dsahern@...il.com>
To: linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Cc: acme@...stprotocols.net, mingo@...e.hu, peterz@...radead.org,
fweisbec@...il.com, paulus@...ba.org, tglx@...utronix.de,
David Ahern <dsahern@...il.com>
Subject: [PATCH 4/6] perf record: add time-of-day option
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 <dsahern@...il.com>
---
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
--
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