Bug 6015

Summary:	Lttng does not work on qemuarm due to lttng-tracer module not found
Product:	[Runtime] General Runtime	Reporter:	Alexandra Safta <alexandra.safta>
Component:	General Runtime	Assignee:	Bruce Ashfield <bruce.ashfield>
Status:	RESOLVED FIXED	QA Contact:	Catalin Scrieciu <catalin.scrieciu>
Severity:	normal
Priority:	Medium	CC:	alexandru.c.georgescu, catalin.scrieciu, dvhart, pokylinux, tom.zanussi
Version:	1.6
Target Milestone:	1.7
Hardware:	x86
OS:	Multiple
Whiteboard:
OS type for building Yocto:	---	Type of Regression:	New (Never tested)
Verified:		Documentation change:	Don't know

Description Alexandra Safta 2014-03-20 13:16:52 UTC

When running lttng tools on target-side tests and executing: lttng calibrate -k 
the following error is displayed: 
modprobe: FATAL: Module lttng-tracer not found. 
Error: Unable to load module lttng-tracer 
Error: Unable to remove module lttng-tracer 
Warning: No kernel tracer available 
Error: Kernel tracer not available 


The same error also affects channel enabling:
root@qemuarm:~# lttng enable-channel ch1 -k 
modprobe: FATAL: Module lttng-tracer not found. 
Error: Unable to load module lttng-tracer 
Error: Unable to remove module lttng-tracer 
Warning: No kernel tracer available 
Error: Channel ch1: Kernel tracer not available (session auto-20140320-095910) 
Warning: Some command(S)went wrong 
root@qemuarm:~#

Comment 1 Tom Zanussi 2014-03-20 22:51:29 UTC

See below for the threads discussing why this is.  Basically, lttng-modules has been blacklisted by the lttng team for arm, therefore no lttng-modules.

I originally also removed lttng-tools for that reason, but because lttng-ust is still valid, it was added back, and though lttng-tools exists, it's useless on arm other than for lttng-ust because lttng-modules isn't available on arm.

https://www.mail-archive.com/openembedded-core@lists.openembedded.org/msg50051.html

https://www.mail-archive.com/openembedded-core@lists.openembedded.org/msg50054.html

Comment 2 Darren Hart 2014-03-20 23:35:21 UTC

THis sounds like a closed wait for upstream or closed not a bug. Thoughts?

Comment 3 Tom Zanussi 2014-03-20 23:39:11 UTC

Well, it's a bug, but not something I'd fix, so I guess the best course would be to wait for upstream.

Comment 4 Darren Hart 2014-06-09 22:48:45 UTC

Following Tom's advice and marking WaitForUpstream.

Comment 5 Bruce Ashfield 2014-08-11 03:21:11 UTC

lttng-modules has been re-enabled for ARM in oe-core master. So this
is now available.

Comment 6 Alexandru Georgescu 2014-08-11 08:18:45 UTC

Catalin, 
Can you verify this on our next FP?


Thanks,
Alex.