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From: francis.deslauriers@mail.utoronto.ca (Francis Deslauriers)
Subject: [lttng-dev] Beginner question: how to inspect scheduling of multi-threaded user application?
Date: Wed, 24 Aug 2016 12:17:40 -0400	[thread overview]
Message-ID: <CADcCL0hqkvEPZEu85GzJnJKi9nOi0wntpOYoVz37QhcRVpb+=g@mail.gmail.com> (raw)
In-Reply-To: <35de22c3d2034f3abb75596477b23e3a@EUX13SRV1.EU.NEC.COM>

Hi David,
If you specifically want to trace the scheduling of the threads of your
app, you don't need custom tracepoints.
Enabling the sched_switch kernel event will give you both of cpu id and
thread id. Look at the cpu_id and next_tid fields.

You can enable the sched_switch event using : lttng enable-event -k
sched_switch

Cheers,
Francis

2016-08-24 3:17 GMT-04:00 David Aldrich <David.Aldrich at emea.nec.com>:

> Hi
>
>
>
> I am new to tracing in Linux and to lttng. I have a multi-threaded user
> application and I want to see:
>
>
>
> 1)      When the threads are scheduled to run
>
> 2)      Which cores the threads are running on.
>
>
>
> I have installed lttng on Ubuntu 14.04 LTS.  I am expecting to visualise
> the trace using TraceCompass.
>
>
>
> I have read the following doc section:
>
>
>
> http://lttng.org/docs/#doc-tracing-your-own-user-application
>
>
>
> In order to collect my trace, must I define custom tracepoint definitions ( in
> a tracepoint provider header file ), and insert tracepoints into my user
> application, or is there a simpler way of achieving my goal?
>
>
>
> Best regards
>
>
>
> David
>
>
>
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>
>
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  reply	other threads:[~2016-08-24 16:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-24  7:17 David Aldrich
2016-08-24 16:17 ` Francis Deslauriers [this message]
2016-08-24 16:35   ` Jonathan Rajotte
2016-08-24 16:39     ` Jonathan Rajotte
2016-08-26  7:49       ` David Aldrich
2016-08-26 14:53         ` Jonathan Rajotte Julien

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