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From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Subject: [ltt-dev] Traces data alignment
Date: Tue, 24 Mar 2009 09:11:31 -0400	[thread overview]
Message-ID: <20090324131131.GB24346@Krystal> (raw)
In-Reply-To: <200903240934.37456.jerome.stadelmann@heig-vd.ch>

* J?r?me Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> On vendredi 20 mars 2009 15:53:55 Mathieu Desnoyers wrote:
> > * J?r?me Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> > > On jeudi 19 mars 2009 18:00:01 Mathieu Desnoyers wrote:
> > > > * J?r?me Stadelmann (jerome.stadelmann at heig-vd.ch) wrote:
> > > > > Hi everybody,
> > > > > 
> > > > > I'm working on a LTTng traces parser and I'm a little bit blocked on the alignment. Can someone please explain how and where it is coded ?
> > > > 
> > > > The lttv lib "ltttraceread" should do that for you.
> > >  
> > > > > What are the roles of the alignment defined in the traces header and the one defined in the metadata file in the core_marker_id ?
> > > > > 
> > > > 
> > > > They tell that a specific tracefile content is aligned or not, and if
> > > > the content of a given event is aligned or not. You should really have
> > > > at least a look at the ltt lib traceread reference implementation.
> > > 
> > > Thank you. This library helped me a lot. I see that there is an up to 2 byte alignment in the core marker id event definition. Is there the only special case ?
> > > I've searched the uses of the ltt_align function. Are there other functions to look for ?
> > > 
> > 
> > Looking at ltt_align use is a good starting point.
> > 
> > Can you point out to the specific package/version/file/line you refer to
> > for the core marker id "special case" you talk about here ?
> > 
> 
> I think I've understood now. The alignment in the metadata file is
> "hardcoded" as 2 byte because the id field is the biggest value and is
> coded as a 2 bytes value. Am I right ?
> 

Possibly. Again, can you point out which package/version/file/line you
refer to so I can be sure we are talking about the same piece of code ?
Telling which file and function, with a cut and paste of the context,
would be nice to have.

Mathieu

> > Mathieu
> > 
> > > Jerome
> > >  
> > > > Mathieu
> > > > 
> > > > > Regards,
> > > > > 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




  reply	other threads:[~2009-03-24 13:11 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-19 15:06 Jérôme Stadelmann
2009-03-19 17:00 ` Mathieu Desnoyers
2009-03-20  7:16   ` Jérôme Stadelmann
2009-03-20 14:53     ` Mathieu Desnoyers
2009-03-23  7:03       ` Jérôme Stadelmann
2009-03-24  8:34       ` Jérôme Stadelmann
2009-03-24 13:11         ` Mathieu Desnoyers [this message]
2009-03-25  6:16           ` Jérôme Stadelmann
2009-03-25  7:05             ` Mathieu Desnoyers
2009-03-26  6:41               ` Jérôme Stadelmann

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