[ltt-dev] LTTng and multi-core

[Klein, Russell]

Mathieu,

Unfortunately, I think I'm stuck on this version.  I have linux version
2.6.30 as a base, this is what Freescale ported to the platform I am
using. My understanding is that 0.12.20 is the highest version which
supports trace version 2.3.  I have version 0.159 of LTTng - I believe
that this is the highest version supported by 2.6.30 (tho I can't recall
why I think that, as the compatibility matrix says I should be able to
go up to 0.170)

Given that I need to be on Linux 2.6.30 - what are my best versions to
be using?

Thanks, Russ Klein

-----Original Message-----
From: Mathieu Desnoyers [mailto:compudj at krystal.dyndns.org] 
Sent: Wednesday, October 13, 2010 7:09 PM
To: Klein, Russell
Cc: ltt-dev at lists.casi.polymtl.ca
Subject: Re: [ltt-dev] LTTng and multi-core

Oh, I thought you were viewing your trace with the Eclipse TMF LTTng
viewer. lttv-gui is indeed the current "stable" tool to use.

LTTV 0.12.20 is quite old though. There might be bugs in it that were
fixed since then. Can you try gathering a trace with the latest LTTng
version and try to view it with LTTV, so we can figure out if the
problem is still there before we start looking for it ?

Thanks,

Mathieu

* Klein, Russell (russell_klein at mentor.com) wrote:
> Mathieu,
> 
> I am viewing the results in lttv-gui, I have version 0.12.20.  Are you
> asking me to run it in "lttv"?  I'm not sure how to run that.
> 
> There are 2 views in lttv-gui, which seem to contradict each other.
In
> the "event viewer" the COREID field is the same for all events
> associated with all threads created by the application.  However, in
the
> "control flow viewer" it shows several threads/processes as
concurrently
> in the "run" state.  Which I assume can only occur if the threads are
on
> different cores.  
> 
> I'm not sure how to interpret the "resource viewer", but it appears to
> have a lot of activity on all cores during the execution of the app.
> This would tend to confirm that the threads are spread across the
cores,
> as expected.
> 
> Thanks, Russ
> 
> 
> -----Original Message-----
> From: Mathieu Desnoyers [mailto:compudj at krystal.dyndns.org] 
> Sent: Wednesday, October 13, 2010 3:51 PM
> To: Klein, Russell
> Cc: ltt-dev at lists.casi.polymtl.ca
> Subject: Re: [ltt-dev] LTTng and multi-core
> 
> * Klein, Russell (russell_klein at mentor.com) wrote:
> > An additional data point on the message forwarded by Francois
> > (http://lttng.org/pipermail/ltt-dev/2010-October/003369.html) :
> > 
> >  
> > 
> > I added the function sched_getcpu() to the application, so I could
see
> > the core id for each thread as it was launched.  The core-id as
> reported
> > by the sched_getcpu does *not* match the values in the CPUID field
in
> > the event viewer.  It appears that the values in the event viewer
are
> > incorrect.
> 
> Can you try viewing your trace with the LTTV viewer and compare ?
> 
> It's available on the http://lttng.org website.
> 
> Thanks,
> 
> Mathieu
> 
> 
> -- 
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com