[OE-core] lttng-modules may trigger deadlock in the timekeeping subsystem with Linux <= 3.10.13, <= 3.11.2

[Woegerer, Paul]

Hi,

looking at the following commits shows that the current version of
lttng-modules 2.3.x can trigger a deadlock in the timekeeping subsystem
of Linux.

http://git.lttng.org/?p=lttng-modules.git;a=commit;h=fc8216ae9ec5d18172d8227d179475e7cc1fb45c
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=9998f5216f4641a79e158135c4c1658dcc6cd2d8
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=e14bf96416c39675a5f785b032d1c5279020b93d

This is caused by a bug in the kernel that was introduced in 3.10. The
problem is already fixed in Linux 3.10.14, 3.11.3 and 3.12. See:
http://marc.info/?l=linux-kernel&m=137894350929349

lttng-modules 2.3.2 contains preprocessor-code that makes sure that
building of lttng-modules fails for the unlucky combinations of kernel
and lttng-modules. The problem is when we update our lttng-modules 2.3.0
to 2.3.2 then we would have lttng-modules failing to build for our qemu*
MACHINEs.

Any recommendations on how we should address this ?

Many thanks,
Paul

-- 
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division