From: Jiri Olsa <jolsa@redhat.com>
To: "Wangnan (F)" <wangnan0@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
David Ahern <dsahern@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Milian Wolff <milian.wolff@kdab.com>,
linux-kernel@vger.kernel.org, pi3orama <pi3orama@163.com>,
lizefan 00213767 <lizefan@huawei.com>
Subject: Re: [BUG REPORT] perf tools: x86_64: Broken calllchain when sampling taken at 'callq' instruction
Date: Wed, 18 Nov 2015 09:48:42 +0100 [thread overview]
Message-ID: <20151118084842.GA10182@krava.brq.redhat.com> (raw)
In-Reply-To: <564C26C4.2040603@huawei.com>
On Wed, Nov 18, 2015 at 03:20:36PM +0800, Wangnan (F) wrote:
SNIP
>
> Then use perf to trace it:
>
> # ./pref record -g -F 9 --call-graph dwarf ./test_dwarf_unwind
> # ./perf report --no-children --stdio
> ...
> 1.23% test_dwarf_unwi test_dwarf_unwind [.] funcc
> |
> ---funcc
> |
> |--0.62%-- funcb
> | funca
> | main
> | __libc_start_main
> | _start
> |
> --0.62%-- 0 <-- I applied Jiri's patch in [1] so see this
> 0,
> which indicates a broken call chain.
can't see this case after multiple running your test,
just the 'end-of-the-callchain' zeros
49.14% test_dwarf_unwi [vdso] [.] __vdso_gettimeofday
|
---__vdso_gettimeofday
funcc
funcb
funca
main
__libc_start_main
_start
0
40.78% test_dwarf_unwi [vdso] [.] 0x0000000000000987
|
---0x7ffe28ab7987
__vdso_gettimeofday
funcc
funcb
funca
main
__libc_start_main
_start
0
what kernel do you have?
jirka
next prev parent reply other threads:[~2015-11-18 8:48 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-18 7:20 Wangnan (F)
2015-11-18 8:00 ` Wangnan (F)
2015-11-18 8:20 ` Ingo Molnar
2015-11-18 8:42 ` Wangnan (F)
2015-11-18 8:49 ` Wangnan (F)
2015-11-19 6:37 ` Ingo Molnar
2015-11-19 6:45 ` Wangnan (F)
2015-11-19 10:23 ` Ingo Molnar
2015-11-19 10:43 ` Wangnan (F)
2015-11-19 11:28 ` Peter Zijlstra
2015-11-19 11:23 ` Peter Zijlstra
2015-11-27 8:38 ` Ingo Molnar
2015-11-30 9:28 ` Peter Zijlstra
2015-12-01 7:28 ` Ingo Molnar
2015-12-01 8:38 ` Peter Zijlstra
2015-12-01 16:11 ` Ingo Molnar
2015-12-01 17:21 ` Peter Zijlstra
2015-12-02 9:55 ` Ingo Molnar
2015-11-18 8:48 ` Jiri Olsa [this message]
2015-11-18 9:02 ` Wangnan (F)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20151118084842.GA10182@krava.brq.redhat.com \
--to=jolsa@redhat.com \
--cc=acme@kernel.org \
--cc=dsahern@gmail.com \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan@huawei.com \
--cc=milian.wolff@kdab.com \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=pi3orama@163.com \
--cc=wangnan0@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome