>   Recall that building lttng-ust on a Beagle Bone Black (Angstrom GNU/Linux 
> v2012.12 (Core edition) on kernel 3.8.13), 
>the make fails at the CCLD of libringbuffer_la-ring_buffer_frontend.lo with an 
>unexpected (and so far unexplained) 
>group of "Error: selected processor does not support ARM mode 'dmb'" (25 
>times).
>
> [...]
>   At this point I can only try lttng-tools in its "kernel tracing only" mode. 
>  [...]
>
>   I run into trouble quickly, however.  The CC of 
> common/hashtable/rculfhash.lo runs into "Error: selected processor 
>does not support ARM mode 'dmb'" (8 times).  The make aborts at this point.

   Progress on this front.  I did one thing: I edited 
userspace-rcu/urcu/arch/arm.h to comment out the #ifdef CONFIG_RCU_ARM_HAVE_DMB 
defines so that userspace-rcu builds "dmb-less".  Once rebuilt and 
re-installed, I can then move on to try lttng-tools again, and this time it 
passes the rculfhash.lo step.  It dies much later for a completely unrelated 
reason which I expect to fix shortly.  At this point I also expect a rebuild of 
lttng-ust would succeed.

   So it looks like the problem is that the makefiles of lttng-tools and 
lttng-ust somehow impose too strong an architecture constraint on their linker 
(i.e. dmb-less generic ARM instead of ARMv7 with dmb).

   I hope this helps.

Daniel U. Thibault
Protection des systèmes et contremesures (PSC) | Systems Protection & 
Countermeasures (SPC) Cyber sécurité pour les missions essentielles (CME) | 
Mission Critical Cyber Security (MCCS) RDDC - Centre de recherches de 
Valcartier | DRDC - Valcartier Research Centre
2459 route de la Bravoure
Québec QC  G3J 1X5
CANADA
Vox : (418) 844-4000 x4245
Fax : (418) 844-4538
NAC : 918V QSDJ <http://www.travelgis.com/map.asp?addr=918V%20QSDJ>
Gouvernement du Canada | Government of Canada 
<http://www.valcartier.drdc-rddc.gc.ca/>

_______________________________________________
lttng-dev mailing list
[email protected]
http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

Reply via email to