[Xenomai-help] Xenomai on i7-870

[Jakub Nowacki <j.s.nowacki@domain.hid>]

Dear All,

I've recently installed Xenomai for our RT lab machine that uses RTXI 
(http://www.rtxi.org/). I followed the installation instruction on the 
web page but I got a number of issues in the process. Just to set some 
common ground: the machine is mentioned i7-870 on Intel's Q57 board; the 
setup is done for kernel 2.6.37.6 on Xubuntu 11.04 with the latest 
stable Xenomai (2.5.6) and Adeos patch. As for myself, I have some 
experience with Linux kernel setup but I'm not an expert.

Before I found that the Intel's white paper describing Xenomai 
installation [Ugal 2009] shouldn't be used, I followed some suggestions 
there and disabled power management (PM) completely. The kernel compiles 
without any problems and works fine, but I the system sees only 4 out of 
8 cores (just a reminder that i7-870 has 4 cores but 8 threads that are 
normally visible as CPUs). It is not end of the world for me at this 
point and the system seems to work fine (I have low latencies etc.) but 
I wanted to fix that.

I've started to read into the installation and other resources, and 
disabled only the important bits, i.e. CONFIG_CPU_FREQ, 
CONFIG_ACPI_PROCESSOR, CONFIG_INTEL_IDLE; the rest of the kernel is 
pretty much generic Ubuntu config (I used 
https://wiki.ubuntu.com/KernelTeam/GitKernelBuild as a reference). The 
outcome is that machine now seems to have all cores but just after login 
the system freezes completely (without running anything related with 
Xenomai, just a couple of seconds after each login into Xfce). I 
actually managed to find on the mailing list that it can be caused by 
CONFIG_HPET_TIMER but I'm not able to disable it. Meaning, it is 
excluded from config GUIs (I've tried practically all of them) and if I 
change it manually in the .config file, it just somehow switches back to 
being enabled when I compile the kernel.
BTW I've tried the APIC options from the FAQ, but they do not fix the 
freezing. Also, HPET_TIMER is enabled in the previous kernel config 
where I disable whole PM, and the system seems to work fine with it.

Also I had similar problem with CONFIG_PCI_MSI, namely, it is blocked 
(cannot be disabled) in the GUI when PM is enabled (or something there, 
I'm not sure). But than later in the HPET thread I've found that I 
should leave MSI enabled, hence, I'm not sure what should I do here.

Moreover, there is a problem with CONFIG_APM in this kernel, namely, it 
seems to not be there. I'm not sure if it just does not exist for the 
new kernel or I'm not doing something right.

Do you have any suggestions? I can provide you with the config file. 
Also, I can try doing some test and debugging if it's needed.

Best wishes,

Jakub