From: Greg KH <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
alan@lxorguk.ukuu.org.uk,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Ingo Molnar <mingo@elte.hu>,
Robert Richter <robert.richter@amd.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: [01/15] perf evsel: Fix an issue where perf report fails to show the proper percentage
Date: Thu, 16 Feb 2012 16:55:10 -0800 [thread overview]
Message-ID: <20120217005509.959166336@linuxfoundation.org> (raw)
In-Reply-To: <20120217005650.GA17119@kroah.com>
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
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>
---
tools/perf/util/evsel.c | 1 +
1 file changed, 1 insertion(+)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -348,6 +348,7 @@ int perf_event__parse_sample(const union
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)
next prev parent reply other threads:[~2012-02-17 0:55 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-17 0:56 [00/15] 3.0.22-stable review Greg KH
2012-02-17 0:55 ` Greg KH [this message]
2012-02-17 0:55 ` [02/15] perf tools: Fix perf stack to non executable on x86_64 Greg KH
2012-02-17 0:55 ` [03/15] drm/i915: no lvds quirk for AOpen MP45 Greg KH
2012-02-17 0:55 ` [04/15] hwmon: (f75375s) Fix bit shifting in f75375_write16 Greg KH
2012-02-17 0:55 ` [05/15] lib: proportion: lower PROP_MAX_SHIFT to 32 on 64-bit kernel Greg KH
2012-02-17 0:55 ` [06/15] relay: prevent integer overflow in relay_open() Greg KH
2012-02-17 0:55 ` [07/15] mac80211: timeout a single frame in the rx reorder buffer Greg KH
2012-02-17 0:55 ` [08/15] writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue Greg KH
2012-02-17 0:55 ` [09/15] gpio/pca953x: Fix warning of enabled interrupts in handler Greg KH
2012-02-17 0:55 ` [10/15] hwmon: (f75375s) Fix automatic pwm mode setting for F75373 & F75375 Greg KH
2012-02-17 0:55 ` [11/15] crypto: sha512 - Use binary and instead of modulus Greg KH
2012-02-17 0:55 ` [12/15] crypto: sha512 - Avoid stack bloat on i386 Greg KH
2012-02-17 0:55 ` [13/15] ALSA: intel8x0: Fix default inaudible sound on Gateway M520 Greg KH
2012-02-17 0:55 ` [14/15] xen pvhvm: do not remap pirqs onto evtchns if !xen_have_vector_callback Greg KH
2012-02-17 0:55 ` [15/15] slub: fix a possible memleak in __slab_alloc() Greg KH
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