From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: ahmadkhorrami <ahmadkhorrami@ut.ac.ir>
Cc: linux-trace-users <linux-trace-users@vger.kernel.org>,
lttng-dev <lttng-dev@lists.lttng.org>,
Jeremie Galarneau <jeremie.galarneau@efficios.com>,
Namhyung Kim <namhyung@kernel.org>, rostedt <rostedt@goodmis.org>
Subject: Re: Capturing User-Level Function Calls/Returns
Date: Wed, 15 Jul 2020 14:45:18 -0400 (EDT) [thread overview]
Message-ID: <83963025.14828.1594838718290.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <20200715142849.0bfe909a@oasis.local.home>
----- On Jul 15, 2020, at 2:28 PM, rostedt rostedt@goodmis.org wrote:
> On Wed, 15 Jul 2020 20:37:16 +0430
> ahmadkhorrami <ahmadkhorrami@ut.ac.ir> wrote:
>
>> Hi,
>> What is the most efficient way to capture occurrence of a function
>> call/return of a binary program in userspace?
>> It seems the answer is Uprobes. 1) Am I right?
>> But Uprobes use "int" instruction which leads to a switch into kernel
>> mode. 2) Wouldn't it be better to avoid this transition?
>> I'm looking forward to your reply and will be happy to read your
>> opinions.
>> Regards.
>
>
> Hi, I believe LTTng has utilities that can help you trace user space
> programs.
Indeed, it is documented here:
https://lttng.org/docs/#doc-liblttng-ust-cyg-profile
If your program is generating function entry/exit at a very
high rate (which goes beyond your available I/O throughput and
lasts longer than the memory you have available for ring buffers),
you will also probably want to use the "blocking-timeout" option
documented at:
https://lttng.org/docs/#doc-enabling-disabling-channels
Thanks,
Mathieu
>
> I think there's also a users ftrace like utility that Namhyung was
> working on. But I don't know where in the development that is.
>
> -- Steve
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2020-07-15 18:45 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 16:07 Capturing User-Level Function Calls/Returns ahmadkhorrami
2020-07-15 18:28 ` Steven Rostedt
2020-07-15 18:45 ` Mathieu Desnoyers [this message]
2020-07-15 21:39 ` ahmadkhorrami
2020-07-15 21:48 ` Steven Rostedt
2020-07-15 22:25 ` ahmadkhorrami
2020-07-16 1:06 ` [lttng-dev] " Michel Dagenais
2020-07-16 1:49 ` Frank Ch. Eigler
2020-07-16 16:26 ` ahmadkhorrami
2020-07-16 16:20 ` ahmadkhorrami
2020-07-16 16:34 ` ahmadkhorrami
2020-07-16 1:04 ` Namhyung Kim
2020-07-16 16:07 ` ahmadkhorrami
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