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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2012-02-03 22:31:13 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-20 12:48:08 -0800 |
| commit | 795f18956b547f0cfbcaa6d907d2bb05726a6a3e (patch) | |
| tree | 78318177d33d3f5e8438cd029881af98dd94bae2 /tools | |
| parent | 1d05f993784973189395051cc711fdd6dd5eb389 (diff) | |
| download | kernel_samsung_smdk4412-795f18956b547f0cfbcaa6d907d2bb05726a6a3e.zip kernel_samsung_smdk4412-795f18956b547f0cfbcaa6d907d2bb05726a6a3e.tar.gz kernel_samsung_smdk4412-795f18956b547f0cfbcaa6d907d2bb05726a6a3e.tar.bz2 | |
perf evsel: Fix an issue where perf report fails to show the proper percentage
commit a4a03fc7ef89020baca4f19174e6a43767c6d78a upstream.
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.
Problem introduced in:
$ git describe 640c03c
v2.6.37-rc3-83-g640c03c
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120203170113.5190.25558.stgit@localhost6.localdomain6
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | 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 0239eb8..ad2183c 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -348,6 +348,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type, 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) |