[lttng-dev] CentOS 7.3 Support

[Jonathan Rajotte-Julien]

Hi,

On Wed, Jun 07, 2017 at 06:35:58AM -0400, Michael Steppe wrote:
> Great! Thanks Jonathan. As a quick follow up question, I am now seeing some
> warnings about discarded events that I remember reading about in your

Could you give us the output so we can be sure which warnings we are speaking of
exactly?

> release notes somewhere. Is there a way to silence these types of warnings?

You probably do not want to silence them. You are probably better off
configuring your channels correctly based on the workload of your hosts.
Having lost events will hinder your ability to analyze the resulting trace.

See the man page for "lttng enable-channel" [1] for more information on how to
increase the sub-buffers size.

You can also find a more friendly explanation on lttng.org/docs, more
specifically [2] and [3]

[1] http://lttng.org/man/1/lttng-enable-channel/v2.9/
[2] http://lttng.org/docs/v2.9/#doc-channel-overwrite-mode-vs-discard-mode
[3] http://lttng.org/docs/v2.9/#doc-channel-subbuf-size-vs-subbuf-count

Note that these are core concepts and did not change between 2.8 and 2.9 .

Cheers

> 
> Thanks again!
> Michael Steppe
> 
> On Tue, Jun 6, 2017 at 2:59 PM, Jonathan Rajotte-Julien <
> jonathan.rajotte-julien at efficios.com> wrote:
> 
> > Hi,
> >
> > On Tue, Jun 06, 2017 at 01:19:11PM -0400, Michael Steppe wrote:
> > > Hello!
> > >
> > > I had previously built LTTng-modules 2.8.0 from source without issue on
> > > CentOS 7.2 (3.10.0-327 kernel). When I tried to build on CentOS 7.3
> > > (3.10.0-514 kernel), however, it failed with multiple "error: struct has
> > no
> > > member named 'id'" and "error: struct has no member named 'name'"
> > errors. I
> > > tried building LTTng-modules 2.9.2 from source on CentOS 7.3 and was
> > > successful (it also built successfully on CentOS 7.2).
> > >
> > > I was just curious at what version of LTTng-modules did the newer kernel
> > in
> > > CentOS 7.3 get supported. I would like to jump as small as possible, so
> > if
> > > there was a version of the modules between 2.8.0 and 2.9.2 that was
> > > supported that would be great.
> >
> > In the specific case of kernel 3.10.0-514, lttng-modules stable 2.8 is
> > fixed
> > starting from commit f61eb2851f482baee02bb508aef01f67fdb3fbaf (stable 2.8
> > branch) and 5f9ff4e230753160ccfc300d44004b117cf678ad (master branch):
> >
> > -----------
> > commit f61eb2851f482baee02bb508aef01f67fdb3fbaf
> > Author: Michael Jeanson <mjeanson at efficios.com>
> > Date:   Wed Dec 7 14:17:33 2016 -0500
> >
> >     Fix: asoc instrumentation for RHEL 7.3
> >
> > Signed-off-by: Michael Jeanson <mjeanson at efficios.com>
> > Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> > -----------
> >
> > Hence you can upgrade lttng-modules to any tag greater or equal to v2.8.4.
> >
> > If you can't upgrade to the 2.9.x stable release the v2.8.5 tag is
> > your best bet.
> >
> > Cheers
> >
> > >
> > > Thanks!
> > > Michael Steppe
> >
> > > _______________________________________________
> > > lttng-dev mailing list
> > > lttng-dev at lists.lttng.org
> > > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
> >
> >
> > --
> > Jonathan Rajotte-Julien
> > EfficiOS
> >

-- 
Jonathan Rajotte-Julien
EfficiOS