[ltt-dev] LTTng traces

Mathieu Desnoyers compudj at krystal.dyndns.org
Tue Feb 10 12:29:52 EST 2009


* Jérôme Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> Thank you for your information. That helped me a lot.
> Now I've another question about it, is there a file or header where I can find all the event ID's and their parameters ?
> I know that I can find some informations about the parameters in the xxx-trace.c files but is there another way to get this and especially the ID's ?
> 

event IDs are allocated dynamically. They are listed in the metadata
channel.

Mathieu

> Thanks in advance
> Jerome
> 
> 
> On jeudi 29 janvier 2009 16:06:26 Mathieu Desnoyers wrote:
> > * Jérôme Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> > > Hi Mathieu,
> > > 
> > > Excuse-me for asking again but, is there really no other way to go than scanning the source code in order to understand the traces format and information ?
> > > For your question, I'm using the version 0.82.
> > > 
> > 
> > I would recommend :
> > 
> > starting with ltt/ltt-serialize.c : there is a very lengthy comment in
> > there which explains the format strings and how the generic serializer
> > writes the event data.
> > 
> > Looking at ltt/probes/ltt-type-serializer.h to see how the specialized
> > probes write the event information.
> > 
> > And for a more palatable document :
> > 
> > (latest publicly available version of ISO/IEC 9899:1999, Programming
> > Languages - C)
> > http://www.open-std.org/JTC1/SC22/WG14/www/docs/n1256.pdf
> > 
> > Section 6.7.2.1 Structure and union specifiers
> > 
> > LTTng event fields follow a subset of the ISO C standard for structures.
> > Specific note : unlike the standard C implementations, there is no
> > padding at the end of the event payload (structure). Also note that
> > LTTng does not support bitfields in C structures because they depend on
> > the specific compiler implementation.
> > 
> > Hope this helps,
> > 
> > Mathieu
> > 
> > > Best regards,
> > > Jerome
> > > 
> > > Le jeudi 22 janvier 2009 21:07:49 Mathieu Desnoyers, vous avez écrit :
> > > > * Stadelmann Jérôme (jerome.stadelmann at heig-vd.ch) wrote:
> > > > > Hi all,
> > > > > 
> > > > > I'm trying to parse and decode the trace files but it is not so easy.
> > > > > Is there a place or a file where I could find a description of all the facilities and the events id's ?
> > > > > 
> > > > 
> > > > In the current LTTng, there is no such thing as "facility" anymore.
> > > > Which LTTng version are you working with ?
> > > > 
> > > > Mathieu
> > > > 
> > > > > Thank you
> > > > > Jerome
> > > > > 
> > > > > _______________________________________________
> > > > > ltt-dev mailing list
> > > > > ltt-dev at lists.casi.polymtl.ca
> > > > > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
> > > > > 
> > > > 
> > > 
> > 
> 

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68




More information about the lttng-dev mailing list