[PATCH 48/75] perf top: Save and display the lost count stats

Arnaldo Carvalho de Melo
2018-12-06T21:29:47Z

From: Jiri Olsa <jolsa@kernel.org>

Add a 'lost count' to 'perf top' headers:

# perf top --stdio
PerfTop: 3850 irqs/sec kernel:49.0% exact: 100.0% lost: 0/0 [4000Hz cycles:ppp], (all, 8 CPUs)

# perf top
Samples: 0 of event 'cycles:ppp', 4000 Hz, Event count (approx.): 0 lost: 0/0

The format is: <current period lost>/<total lost>

Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/n/tip-zo11rn270gij5jtp8fknpf8u@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-top.c | 27 +++++++++++++++++++++++++++
tools/perf/ui/browsers/hists.c | 4 ++++
tools/perf/util/top.c | 6 +++---
tools/perf/util/top.h | 2 +-
4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 1beb3e360521..c02ea537d5a7 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -800,6 +800,29 @@ static void perf_event__process_sample(struct perf_tool *tool,
addr_location__put(&al);
}

+static void
+perf_top__process_lost(struct perf_top *top, union perf_event *event,
+ struct perf_evsel *evsel)
+{
+ struct hists *hists = evsel__hists(evsel);
+
+ top->lost += event->lost.lost;
+ top->lost_total += event->lost.lost;
+ hists->stats.total_lost += event->lost.lost;
+}
+
+static void
+perf_top__process_lost_samples(struct perf_top *top,
+ union perf_event *event,
+ struct perf_evsel *evsel)
+{
+ struct hists *hists = evsel__hists(evsel);
+
+ top->lost += event->lost_samples.lost;
+ top->lost_total += event->lost_samples.lost;
+ hists->stats.total_lost_samples += event->lost_samples.lost;
+}
+
static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
{
struct record_opts *opts = &top->record_opts;
@@ -865,6 +888,10 @@ static void perf_top__mmap_read_idx(struct perf_top *top, int idx)
if (event->header.type == PERF_RECORD_SAMPLE) {
perf_event__process_sample(&top->tool, event, evsel,
&sample, machine);
+ } else if (event->header.type == PERF_RECORD_LOST) {
+ perf_top__process_lost(top, event, evsel);
+ } else if (event->header.type == PERF_RECORD_LOST_SAMPLES) {
+ perf_top__process_lost_samples(top, event, evsel);
} else if (event->header.type < PERF_RECORD_MAX) {
hists__inc_nr_events(evsel__hists(evsel), event->header.type);
machine__process_event(machine, event, &sample);
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index a96f62ca984a..ae208c16c8a3 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -2219,6 +2219,10 @@ static int hists_browser__scnprintf_title(struct hist_browser *browser, char *bf
if (!is_report_browser(hbt)) {
struct perf_top *top = hbt->arg;

+ printed += scnprintf(bf + printed, size - printed,
+ " lost: %" PRIu64 "/%" PRIu64,
+ top->lost, top->lost_total);
+
if (top->zero)
printed += scnprintf(bf + printed, size - printed, " [z]");
}
diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index 8e517def925b..e6582fa6a4db 100644
--- a/tools/perf/util/top.c
+++ b/tools/perf/util/top.c
@@ -46,8 +46,8 @@ size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
samples_per_sec;
ret = SNPRINTF(bf, size,
" PerfTop:%8.0f irqs/sec kernel:%4.1f%%"
- " exact: %4.1f%% [", samples_per_sec,
- ksamples_percent, esamples_percent);
+ " exact: %4.1f%% lost: %" PRIu64 "/%" PRIu64 " [", samples_per_sec,
+ ksamples_percent, esamples_percent, top->lost, top->lost_total);
} else {
float us_samples_per_sec = top->us_samples / top->delay_secs;
float guest_kernel_samples_per_sec = top->guest_kernel_samples / top->delay_secs;
@@ -113,5 +113,5 @@ void perf_top__reset_sample_counters(struct perf_top *top)
{
top->samples = top->us_samples = top->kernel_samples =
top->exact_samples = top->guest_kernel_samples =
- top->guest_us_samples = 0;
+ top->guest_us_samples = top->lost = 0;
}
diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index 9add1f72ce95..1fbcbd79720a 100644
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -22,7 +22,7 @@ struct perf_top {
* Symbols will be added here in perf_event__process_sample and will
* get out after decayed.
*/
- u64 samples;
+ u64 samples, lost, lost_total;
u64 kernel_samples, us_samples;
u64 exact_samples;
u64 guest_us_samples, guest_kernel_samples;
--
2.19.2