From: Jiri Olsa <jolsa@redhat.com>
To: ahmadkhorrami <ahmadkhorrami@ut.ac.ir>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Linux-trace Users <linux-trace-users@vger.kernel.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-trace-users-owner@vger.kernel.org,
Jin Yao <yao.jin@linux.intel.com>
Subject: Re: Wrong Perf Backtraces
Date: Mon, 23 Mar 2020 09:49:42 +0100 [thread overview]
Message-ID: <20200323084942.GA1534489@krava> (raw)
In-Reply-To: <21b3df4080709f193d62b159887e2a83@ut.ac.ir>
On Mon, Mar 23, 2020 at 07:48:26AM +0430, ahmadkhorrami wrote:
> Here is a link to the detailed question at Stackoverflow:
>
> https://stackoverflow.com/questions/60766026/wrong-perf-backtraces
hi,
what perf version are you running?
jirka
>
> I can copy it here, if needed.
>
> Thanks
>
> On 2020-03-23 05:04, Steven Rostedt wrote:
>
> > On Mon, 23 Mar 2020 00:54:01 +0430
> > ahmadkhorrami <ahmadkhorrami@ut.ac.ir> wrote:
> >
> >> Hi,
> >> I used "Perf" to extract call graphs in an evince benchmark. The command
> >> used is as follows:
> >> sudo perf record -d --call-graph dwarf -c 10000 e
> >> mem_load_uops_retired.l3_miss:uppp /opt/evince-3.28.4/bin/evince
> >>
> >> I extracted the backtraces using "perf script" and found out that there
> >> are many corrupted backtrace instances. Some contained repeated function
> >> calls, for example two consecutive gmallocn()s exactly at the same
> >> offsets. There are also some backtraces where the callers and callees do
> >> not match.
> >
> > Could you show some examples of the backtraces you mention?
> >
> >> Note that that mappings are correct. In other words, each single line of
> >> the reported backtraces is correct (i.e., addresses match with
> >> functions). But is seems that there are some function calls in the
> >> middle, which are missed by "Perf". Strangely, in all runs (and also
> >> with different sampling frequencies) the problem occurs exactly at the
> >> same place.
> >>
> >> I am really confused and looking forward to any help. I can also send
> >> backtraces if needed.
> >
> > -- Steve
next prev parent reply other threads:[~2020-03-23 8:51 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <157597d74ff17f781d9de7e7e3defd13@ut.ac.ir>
2020-03-22 20:24 ` Wrong Perf Backtraces ahmadkhorrami
2020-03-23 0:34 ` Steven Rostedt
[not found] ` <21b3df4080709f193d62b159887e2a83@ut.ac.ir>
2020-03-23 8:49 ` Jiri Olsa [this message]
2020-03-23 10:03 ` ahmadkhorrami
2020-03-25 15:18 ` ahmadkhorrami
2020-03-25 15:46 ` Jiri Olsa
2020-03-25 18:54 ` ahmadkhorrami
2020-03-25 18:58 ` Arnaldo Carvalho de Melo
2020-03-25 19:10 ` ahmadkhorrami
2020-03-25 19:28 ` Arnaldo Carvalho de Melo
2020-03-25 20:01 ` ahmadkhorrami
2020-03-25 20:39 ` Jiri Olsa
2020-03-25 21:02 ` Jiri Olsa
2020-03-25 21:09 ` Steven Rostedt
2020-03-25 21:37 ` ahmadkhorrami
2020-03-25 21:46 ` Jiri Olsa
2020-03-25 22:21 ` ahmadkhorrami
2020-03-25 23:09 ` ahmadkhorrami
2020-03-26 9:59 ` Jiri Olsa
2020-03-26 13:20 ` ahmadkhorrami
2020-03-26 15:39 ` Jiri Olsa
2020-03-26 18:19 ` ahmadkhorrami
2020-03-26 18:21 ` ahmadkhorrami
2020-03-27 9:20 ` Jiri Olsa
2020-03-27 10:59 ` ahmadkhorrami
2020-03-27 11:04 ` ahmadkhorrami
2020-03-27 12:10 ` Milian Wolff
2020-03-27 12:58 ` ahmadkhorrami
2020-03-27 13:25 ` Milian Wolff
2020-03-27 13:33 ` ahmadkhorrami
2020-03-27 18:43 ` ahmadkhorrami
2020-03-27 22:37 ` Jiri Olsa
2020-03-27 23:12 ` ahmadkhorrami
2020-03-28 23:34 ` Jiri Olsa
2020-03-29 0:43 ` ahmadkhorrami
2020-03-29 1:16 ` ahmadkhorrami
2020-03-29 11:19 ` Jiri Olsa
2020-03-29 11:52 ` ahmadkhorrami
2020-03-29 12:08 ` Jiri Olsa
2020-03-29 12:39 ` ahmadkhorrami
2020-03-29 13:50 ` Milian Wolff
2020-03-29 14:23 ` ahmadkhorrami
2020-03-29 19:20 ` Jiri Olsa
2020-03-30 6:09 ` Milian Wolff
2020-03-30 13:07 ` Jiri Olsa
2020-03-30 13:49 ` ahmadkhorrami
2020-03-30 19:05 ` ahmadkhorrami
2020-03-30 21:05 ` debuginfod-based dwarf downloading, was " Frank Ch. Eigler
2020-03-31 9:26 ` Jiri Olsa
2020-03-31 14:00 ` Frank Ch. Eigler
2020-03-31 4:43 ` ahmadkhorrami
2020-03-31 9:30 ` Jiri Olsa
2020-03-31 11:53 ` ahmadkhorrami
2020-03-31 12:43 ` ahmadkhorrami
2020-03-31 13:20 ` Jiri Olsa
2020-03-31 13:39 ` ahmadkhorrami
2020-03-31 14:44 ` Milian Wolff
2020-03-31 15:02 ` ahmadkhorrami
2020-03-31 15:05 ` ahmadkhorrami
2020-03-31 15:29 ` Milian Wolff
2020-03-31 16:10 ` Arnaldo Carvalho de Melo
2020-03-31 19:20 ` ahmadkhorrami
2020-03-31 19:17 ` ahmadkhorrami
2020-03-31 20:57 ` ahmadkhorrami
2020-04-04 1:01 ` ahmadkhorrami
2020-04-11 16:42 ` ahmadkhorrami
2020-04-11 21:04 ` ahmadkhorrami
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