Messages in this thread Patch in this message | | | Subject | [RFC PATCH] Perf: Fix an issue where perf report fails to show the proper percentage | From | "Naveen N. Rao" <> | Date | Fri, 03 Feb 2012 22:31:13 +0530 |
| |
This patch fixes an issue where perf report shows nan% for certain perf.data files. The below is from a report for a do_fork probe:
-nan% sshd [kernel.kallsyms] [k] do_fork -nan% packagekitd [kernel.kallsyms] [k] do_fork -nan% dbus-daemon [kernel.kallsyms] [k] do_fork -nan% bash [kernel.kallsyms] [k] do_fork
A git bisect shows commit f3bda2c as the cause. However, looking back through the git history, I saw commit 640c03c which seems to have removed the required initialization for perf_sample->period. The problem only started showing after commit f3bda2c. The below patch re-introduces the initialization and it fixes the problem for me.
With the below patch, for the same perf.data:
73.08% bash [kernel.kallsyms] [k] do_fork 8.97% 11-dhclient [kernel.kallsyms] [k] do_fork 6.41% sshd [kernel.kallsyms] [k] do_fork 3.85% 20-chrony [kernel.kallsyms] [k] do_fork 2.56% sendmail [kernel.kallsyms] [k] do_fork
This patch applies over current linux-tip commit 9949284.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- tools/perf/util/evsel.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index dcfefab..9a11f9e 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -463,6 +463,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type, memset(data, 0, sizeof(*data)); data->cpu = data->pid = data->tid = -1; data->stream_id = data->id = data->time = -1ULL; + data->period = 1; if (event->header.type != PERF_RECORD_SAMPLE) { if (!sample_id_all)
| |