[PATCH 4/4] perf timechart: add more options to IO mode

From: Stanislav Fomichev
Date: Fri Jun 20 2014 - 06:30:37 EST


--io-skip-eagain - don't show EAGAIN errors
--io-min-time - make small io bursts visible
--io-merge-dist - merge adjacent events

Signed-off-by: Stanislav Fomichev <stfomichev@xxxxxxxxxxxxxx>
---
tools/perf/Documentation/perf-timechart.txt | 13 +++++
tools/perf/builtin-timechart.c | 75 ++++++++++++++++++++++++++++-
2 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/tools/perf/Documentation/perf-timechart.txt b/tools/perf/Documentation/perf-timechart.txt
index ec6b46c7bca0..df98d1c82688 100644
--- a/tools/perf/Documentation/perf-timechart.txt
+++ b/tools/perf/Documentation/perf-timechart.txt
@@ -64,6 +64,19 @@ TIMECHART OPTIONS
duration or tasks with given name. If number is given it's interpreted
as number of nanoseconds. If non-numeric string is given it's
interpreted as task name.
+--io-skip-eagain::
+ Don't draw EAGAIN IO events.
+--io-min-time=<nsecs>::
+ Draw small events as if they lasted min-time. Useful when you need
+ to see very small and fast IO. It's possible to specify ms or us
+ suffix to specify time in milliseconds or microseconds.
+ Default value is 1ms.
+--io-merge-dist=<nsecs>::
+ Merge events that are merge-dist nanoseconds apart.
+ Reduces number of figures on the SVG and makes it more render-friendly.
+ It's possible to specify ms or us suffix to specify time in
+ milliseconds or microseconds.
+ Default value is 1us.

RECORD OPTIONS
--------------
diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index 011569becc65..732dc408ee0b 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -62,7 +62,10 @@ struct timechart {
topology;
/* IO related settings */
u64 io_events;
- bool io_only;
+ bool io_only,
+ skip_eagain;
+ u64 min_time,
+ merge_dist;
};

struct per_pidcomm;
@@ -755,7 +758,7 @@ static int pid_end_io_sample(struct timechart *tchart, int pid, int type,
{
struct per_pid *p = find_create_pid(tchart, pid);
struct per_pidcomm *c = p->current;
- struct io_sample *sample;
+ struct io_sample *sample, *prev;

if (!c) {
pr_err("Invalid pidcomm!\n");
@@ -778,6 +781,18 @@ static int pid_end_io_sample(struct timechart *tchart, int pid, int type,
}

sample->end_time = end;
+ prev = sample->next;
+
+ /* we want to be able to see small and fast transfers, so make them
+ * at least min_time long, but don't overlap them */
+ if (sample->end_time - sample->start_time < tchart->min_time)
+ sample->end_time = sample->start_time + tchart->min_time;
+ if (prev && sample->start_time < prev->end_time) {
+ if (prev->err) /* try to make errors more visible */
+ sample->start_time = prev->end_time;
+ else
+ prev->end_time = sample->start_time;
+ }

if (ret < 0) {
sample->err = ret;
@@ -792,6 +807,24 @@ static int pid_end_io_sample(struct timechart *tchart, int pid, int type,
sample->bytes = ret;
}

+ /* merge two requests to make svg smaller and render-friendly */
+ if (prev &&
+ prev->type == sample->type &&
+ prev->err == sample->err &&
+ prev->fd == sample->fd &&
+ prev->end_time + tchart->merge_dist >= sample->start_time) {
+
+ sample->bytes += prev->bytes;
+ sample->merges += prev->merges + 1;
+
+ sample->start_time = prev->start_time;
+ sample->next = prev->next;
+ free(prev);
+
+ if (!sample->err && sample->bytes > c->max_bytes)
+ c->max_bytes = sample->bytes;
+ }
+
tchart->io_events++;

return 0;
@@ -1112,6 +1145,10 @@ static void draw_io_bars(struct timechart *tchart)
for (sample = c->io_samples; sample; sample = sample->next) {
double h = (double)sample->bytes / c->max_bytes;

+ if (tchart->skip_eagain &&
+ sample->err == -EAGAIN)
+ continue;
+
if (sample->err)
h = 1;

@@ -1842,6 +1879,30 @@ parse_highlight(const struct option *opt __maybe_unused, const char *arg,
return 0;
}

+static int
+parse_time(const struct option *opt, const char *arg, int __maybe_unused unset)
+{
+ char unit = 'n';
+ u64 *value = opt->value;
+
+ if (sscanf(arg, "%" PRIu64 "%cs", value, &unit) > 0) {
+ switch (unit) {
+ case 'm':
+ *value *= 1000000;
+ break;
+ case 'u':
+ *value *= 1000;
+ break;
+ case 'n':
+ break;
+ default:
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
int cmd_timechart(int argc, const char **argv,
const char *prefix __maybe_unused)
{
@@ -1854,6 +1915,8 @@ int cmd_timechart(int argc, const char **argv,
.ordered_samples = true,
},
.proc_num = 15,
+ .min_time = 1000000,
+ .merge_dist = 1000,
};
const char *output_name = "output.svg";
const struct option timechart_options[] = {
@@ -1875,6 +1938,14 @@ int cmd_timechart(int argc, const char **argv,
"min. number of tasks to print"),
OPT_BOOLEAN('t', "topology", &tchart.topology,
"sort CPUs according to topology"),
+ OPT_BOOLEAN(0, "io-skip-eagain", &tchart.skip_eagain,
+ "skip EAGAIN errors"),
+ OPT_CALLBACK(0, "io-min-time", &tchart.min_time, "time",
+ "all IO faster than min-time will visually appear longer",
+ parse_time),
+ OPT_CALLBACK(0, "io-merge-dist", &tchart.merge_dist, "time",
+ "merge events that are merge-dist us apart",
+ parse_time),
OPT_END()
};
const char * const timechart_usage[] = {
--
1.8.3.2

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