* [RFC PATCH] Perf: Fix an issue where perf report fails to show the proper percentage
@ 2012-02-03 17:01 Naveen N. Rao
2012-02-07 19:36 ` [tip:perf/core] perf evsel: " tip-bot for Naveen N. Rao
0 siblings, 1 reply; 2+ messages in thread
From: Naveen N. Rao @ 2012-02-03 17:01 UTC (permalink / raw)
To: acme, mingo, linux-kernel; +Cc: robert.richter, ananth, srikar
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)
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [tip:perf/core] perf evsel: Fix an issue where perf report fails to show the proper percentage
2012-02-03 17:01 [RFC PATCH] Perf: Fix an issue where perf report fails to show the proper percentage Naveen N. Rao
@ 2012-02-07 19:36 ` tip-bot for Naveen N. Rao
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot for Naveen N. Rao @ 2012-02-07 19:36 UTC (permalink / raw)
To: linux-tip-commits
Cc: acme, linux-kernel, hpa, mingo, ananth, robert.richter, srikar,
naveen.n.rao, tglx, mingo
Commit-ID: a4a03fc7ef89020baca4f19174e6a43767c6d78a
Gitweb: http://git.kernel.org/tip/a4a03fc7ef89020baca4f19174e6a43767c6d78a
Author: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
AuthorDate: Fri, 3 Feb 2012 22:31:13 +0530
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 6 Feb 2012 18:59:38 -0200
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>
---
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 667f3b7..7132ee8 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)
^ permalink raw reply related [flat|nested] 2+ messages in thread
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