From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: Re: Questions about CTF format Date: Thu, 2 May 2013 16:27:58 -0400 Message-ID: <20130502202758.GE15675__20868.9194209457$1367526511$gmane$org@Krystal> References: <20120705142052.GA23162@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.openrapids.net ([64.15.138.104] helo=blackscsi.openrapids.net) by ltt.polymtl.ca with esmtp (Exim 4.72) (envelope-from ) id 1UY06i-0006Ou-5v for lttng-dev@lists.lttng.org; Thu, 02 May 2013 16:28:00 -0400 Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: lttng-dev-bounces@lists.lttng.org To: Diego Dompe Cc: lttng-dev@lists.lttng.org, tiwg@multicore-association.org List-Id: lttng-dev@lists.lttng.org * Diego Dompe (ddompe@gmail.com) wrote: > Hi Mathieu, > > Thanks for the help. Here is my list of details: > > - Clocks: the spec doesn't explain properly that timestamps are an offset > from the base time of the clock they refer to. Since I was using 64bit > timestamps I somehow assumed that I was using absolute timestamps from the > epoch (although the spec doesn't says it either). Not sure if it was there when you wrote your comment, but the CTF spec currently has: "The "offset_s" and "offset" fields indicate the offset from POSIX.1 Epoch, 1970-01-01 00:00:00 +0000 (UTC), to the zero of value of the clock." > - I saw that the lttng-generated traces for metadata are always a multiple > of 4k in size (at least the ones I generate for either kernel or user > space). I can't find where in the spec it mentions requirements regarding > metadata packet padding. I was generating metadata packets that ended up > right after my TSDL and eclipse wasn't happy about it (although I didn't > try babeltrace). Also I found that the lttng-generated traces have a > "empty" metadata packet after the metadata containing the TSDL, I didn't > find either any documentation regarding this. Babeltrace had a limitation on not accepting packets smaller than 4kB (page size actually), but it is now fixed. Thanks, Mathieu > > Regards, > > Diego > > On Thu, Jul 5, 2012 at 8:20 AM, Mathieu Desnoyers < > mathieu.desnoyers@efficios.com> wrote: > > > * Diego Dompe (ddompe@gmail.com) wrote: > > > Hi, > > > > > > I'm developing a custom tracer for an embedded product that will generate > > > CTF format. I was able to generate generic traces that can be interpreted > > > properly with babeltrace (but not with eclipse, I already file a bug for > > > that), but I found the CTF specification lacking in some aspects (I had > > to > > > peek into lttng-generated CTF traces to figure out some details). I was > > > wondering what is the proper mailing list to clear my questions and > > provide > > > feedback on the CTF specification for improvement in the areas where the > > > documentation is not detailed yet. I don't see any CTF-specific mailing > > > list, it's OK to discuss it here? Or maybe directly with a developer(s)? > > > > Hi Diego, > > > > Yes, this mailing list would be the proper place, along maybe with > > adding the MCA tiwg mailing list in CC, which I'm doing here. > > > > Thanks, > > > > Mathieu > > > > -- > > Mathieu Desnoyers > > Operating System Efficiency R&D Consultant > > EfficiOS Inc. > > http://www.efficios.com > > -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com