From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jyotiswarup.Raiturkar@arm.com (Jyotiswarup Raiturkar)
Date: Thu, 20 May 2010 16:40:06 +0530
Subject: [ltt-dev] LLTng probes
In-Reply-To: <20100519143011.GA16248@Krystal>
References: <34F012EAAD78FB49A2AFF01BF6DCE07602A4A625@ASHWA.Asiapac.Arm.com>
	<20100519143011.GA16248@Krystal>
Message-ID: <34F012EAAD78FB49A2AFF01BF6DCE07602A4AA3F@ASHWA.Asiapac.Arm.com>

>> The probes are connected to the tracepoints with: kernel:marker.c:
set_marker()

Actually my question was where is the actual trace out call made? For
example for the tracepoint defined by DEFINE_TRACE(irq_exit), the trace
out call is trace_irq_exit(). Similarly there is a trace marker called
DEFINE_MARKER_TP() for irq_exit :
Kernel-trace.c : 
	DEFINE_MARKER_TP(kernel, irq_exit, irq_exit, probe_irq_exit,
"handled #1u%u");

But I don't see how this marker is actually hit during execution. What
is the call similar to trace_irq_exit() for the Tracepoint?

Thanks
Jyotiswarup Raiturkar

-----Original Message-----
From: Mathieu Desnoyers [mailto:compudj@krystal.dyndns.org] 
Sent: Wednesday, May 19, 2010 8:00 PM
To: Jyotiswarup Raiturkar
Cc: ltt-dev at lists.casi.polymtl.ca
Subject: Re: [ltt-dev] LLTng probes

* Jyotiswarup Raiturkar (Jyotiswarup.Raiturkar at arm.com) wrote:
> Hello
> 
>  
> 
> I'm looking at LTTng working inside the kernel, and trying to
understand
> the instrumentation.
> 
>  
> 
> However, I am not able to see how the DEFINE_MARKER_TP() macros and
> other probe_* functions in kernel-trace.c are actually used . As I
> understand it, to make the actual trace, modules would have to call
the
> probe_* functions; yet I'm not able to locate these calls.

The probes are connected to the tracepoints with:

kernel:marker.c: set_marker()

                     ret = tracepoint_probe_register_noupdate(
                                elem->tp_name,
                                elem->tp_cb);

Which is called when a marker is enabled. The markers are listed in a
table which is defined by the DEFINE_MARKER_TP() macros.

Thanks,

Mathieu

> 
>  
> 
> Thanks
> 
> Jyoti
> 
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-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
-- 
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium.  Thank you.