perf top: Fix percent output when no samples collected
If there's no sample, kernel and exact percent output at the header
looked like "-nan%".
Tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1368497347-9628-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/top.c b/tools/perf/util/top.c
index 54d37a4..f857b51 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;