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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2012-02-03 22:31:13 +0530 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2012-02-06 18:59:38 -0200 |
| commit | a4a03fc7ef89020baca4f19174e6a43767c6d78a (patch) | |
| tree | 4b32c000a6b8767868293432bf1a6c748b391af8 | |
| parent | bf32c9ebc9890764c7a9984e3a0c8a57a059753d (diff) | |
| download | linux-a4a03fc7ef89020baca4f19174e6a43767c6d78a.tar.gz linux-a4a03fc7ef89020baca4f19174e6a43767c6d78a.tar.bz2 linux-a4a03fc7ef89020baca4f19174e6a43767c6d78a.zip | |
perf evsel: Fix an issue where perf report fails to show the proper percentage
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>
Cc: stable@kernel.org
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>
| -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 667f3b78bb2c..7132ee834e0e 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) |