[Xenomai-help] Xenomai and SMP load balancing

[Arnout Vandecappelle <arnout@domain.hid>]

 [Please keep me in CC]

 Hoi all,

 I have a Xenomai application that I run on an SMP processor (i3 or i5).  
It takes about 90% load on one of the cores (cpu0).  The rest of the system 
is usually idle, except for occasional runs of some compute-intensive batch 
processes (that run in the non-RT Linux domain).

 The problem is that the Linux load balancer doesn't know about the
Xenomai thread.  It therefore tends to select cpu0 as well for the
batch processes.  That means that the batch processes take much longer
then needed.

 I can solve this by reserving one complete core for the Xenomai thread
(by setting /proc/xenomai/affinity to 1 and giving the isolcpus=0 at boot
time).  But this makes it difficult to move to a non-SMT platform, or
to run several Xenomai applications on different cores.

 Is there a better way to let the Linux load balancer take into account
the load of the Xenomai threads?

 Regards,
 Arnout

-- 
Arnout Vandecappelle                               arnout at mind be
Senior Embedded Software Architect                 +32-16-286540
Essensium/Mind                                     http://www.mind.be
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