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Date: Mon, 30 Mar 2015 11:17:16 +0200
From: Philippe Gerum <rpm@xenomai.org>
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Subject: Re: [Xenomai] Q: LTTNG & xenomai status
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To: Michael Haberler <haberlerm@gmail.com>, xenomai <xenomai@xenomai.org>

On 03/30/2015 10:58 AM, Michael Haberler wrote:
> 2015-03-26 23:37 GMT+01:00 Michael Haberler <haberlerm@gmail.com>:
> 
>> what is the status on using LTTNG tracepoints in an RT thread? the last
>> discussion has been a while back, like 2010ish
>>
>> LTTNG 2.5.1 is in the debian jessie stream. Can I use that as-is?
>>
>> Any special precautions I need to take, or do the stock instructions for
>> LTTNG apply?
>>
> 
> noting that CONFIG_FTRACE was disabled for performance reasons:
> http://www.xenomai.org/pipermail/xenomai/2013-January/027272.html
> 
> that would suggest *functionally* it is not an issue, and LTTng layers
> ontop of CONFIG_FTRACE for kernel tracing
> 
> or am I overlooking something?
> 

Functionally it is not an issue, but the LTT core for any given LTT
version might not be entirely safe for running over a kernel with
pipelined interrupts. Fixing this is part of the usual process of
merging LTTng and the I-pipe.

-- 
Philippe.