From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
To: Hemant Kumar <hkshaw@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com,
peterz@infradead.org, oleg@redhat.com,
hegdevasant@linux.vnet.ibm.com, mingo@redhat.com,
anton@redhat.com, systemtap@sourceware.org, namhyung@kernel.org,
aravinda@linux.vnet.ibm.com
Subject: Re: [PATCH v2 0/3] Perf support to SDT markers
Date: Tue, 08 Oct 2013 06:04:00 -0000 [thread overview]
Message-ID: <5253A04E.4020809@hitachi.com> (raw)
In-Reply-To: <20131007063911.11693.33624.stgit@hemant-fedora>
Hi,
(2013/10/07 15:46), Hemant Kumar wrote:
> This patchset helps in probing dtrace style markers(SDT) present in user space
> applications through perf. Notes/markes are placed at important places by the
> developers. They have a negligible overhead when not enabled. We can enable
> them and probe at these places and find some important information like the
> arguments' values, etc.
Thank you for updating!
By the way, could you rebase this series to the latest -tip kernel next time?
It is more convenient for us to test & merge it.
[...]
> - Now use perf to list the markers in the app:
> # perf probe --markers -x ./user_app
>
> %user_app:foo_start
> %user_app:fun_start
Here, what I got.
$ ./perf probe --markers -x /lib64/librt.so
%librt:lll_futex_wake
OK, it lists up markers.
$ ./perf probe --markers -x ./perf
SDT markers not present!
Error : Failed to find SDT markers!(-1)
OK, this shows an error, INHO, it'd better show which binary doesn't have markers.
$ ./perf probe --markers
Failed to open (null)
Error : Failed to find SDT markers!(-1)
Hmm, it's a bit odd error. It should check if there is an elf binary is specified.
$ ./perf probe --markers /lib64/librt.so
%librt:lll_futex_wake
It seems to work without -x. However, that is only when the path is started with /.
And also the usage is not described by --help.
$ ./perf probe --markers ./perf
Semantic error :File always requires line number or lazy pattern.
Error: Parse Error. (-22)
So, to avoid confusion, --markers should abort without -x(--exec) option.
> - And then use perf probe to add a probe point :
>
> # perf probe -x ./user_app -a '%user_app:foo_start'
And also, without -x, -a also exits with an odd error message.
$ ./perf probe -a %libm:slowexp_p6
Failed to open (null)
Error: Failed to add events. (-1)
I'll review each patch soon.
Thank you,
--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com
next prev parent reply other threads:[~2013-10-08 6:04 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-07 6:47 Hemant Kumar
2013-10-07 6:48 ` [PATCH v2 3/3] Documentation regarding perf/sdt Hemant Kumar
2013-10-07 6:48 ` [PATCH v2 1/3] SDT markers listing by perf: Hemant Kumar
2013-10-08 8:57 ` Namhyung Kim
2013-10-08 13:04 ` Hemant
2013-10-08 11:39 ` Masami Hiramatsu
2013-10-08 13:25 ` Hemant
2013-10-07 6:48 ` [PATCH v2 2/3] Support for perf to probe into SDT markers: Hemant Kumar
2013-10-08 9:09 ` Namhyung Kim
2013-10-08 13:09 ` Hemant
2013-10-08 11:47 ` Masami Hiramatsu
2013-10-08 13:30 ` Hemant
2013-10-07 15:48 ` [PATCH v2 0/3] Perf support to SDT markers Frank Ch. Eigler
2013-10-08 9:10 ` Namhyung Kim
2013-10-08 13:10 ` Hemant
2013-10-08 13:32 ` Hemant
2013-10-08 6:04 ` Masami Hiramatsu [this message]
2013-10-08 12:54 ` Hemant
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=5253A04E.4020809@hitachi.com \
--to=masami.hiramatsu.pt@hitachi.com \
--cc=anton@redhat.com \
--cc=aravinda@linux.vnet.ibm.com \
--cc=hegdevasant@linux.vnet.ibm.com \
--cc=hkshaw@linux.vnet.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=srikar@linux.vnet.ibm.com \
--cc=systemtap@sourceware.org \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).