[PATCH 2/9] perf top: Fix percent output when no samples collected

From: Namhyung Kim
Date: Mon May 13 2013 - 22:11:42 EST


From: Namhyung Kim <namhyung.kim@xxxxxxx>

If there's no sample, kernel and exact percent output at the header
looked like "-nan%".

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/util/top.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index 54d37a4753c5..f857b51b6bde 100644
--- a/tools/perf/util/top.c
+++ b/tools/perf/util/top.c
@@ -23,20 +23,31 @@

size_t perf_top__header_snprintf(struct perf_top *top, char *bf, size_t size)
{
- float samples_per_sec = top->samples / top->delay_secs;
- float ksamples_per_sec = top->kernel_samples / top->delay_secs;
- float esamples_percent = (100.0 * top->exact_samples) / top->samples;
+ float samples_per_sec;
+ float ksamples_per_sec;
+ float esamples_percent;
struct perf_record_opts *opts = &top->record_opts;
struct perf_target *target = &opts->target;
size_t ret = 0;

+ if (top->samples) {
+ samples_per_sec = top->samples / top->delay_secs;
+ ksamples_per_sec = top->kernel_samples / top->delay_secs;
+ esamples_percent = (100.0 * top->exact_samples) / top->samples;
+ } else {
+ samples_per_sec = ksamples_per_sec = esamples_percent = 0.0;
+ }
+
if (!perf_guest) {
+ float ksamples_percent = 0.0;
+
+ if (samples_per_sec)
+ ksamples_percent = (100.0 * ksamples_per_sec) /
+ samples_per_sec;
ret = SNPRINTF(bf, size,
" PerfTop:%8.0f irqs/sec kernel:%4.1f%%"
" exact: %4.1f%% [", samples_per_sec,
- 100.0 - (100.0 * ((samples_per_sec - ksamples_per_sec) /
- samples_per_sec)),
- esamples_percent);
+ ksamples_percent, esamples_percent);
} 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;
--
1.7.11.7

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