On Fri, Sep 11, 2009 at 4:03 PM, Jan Kiszka <[email protected]> wrote: > Stephen Sinclair wrote: >> Hello, >> >> I am trying to install Xenomai. After patching the kernel (I have >> tried with 2.6.29.5 and 2.6.30.5), I get the following error message: >> >> >> $ make >> scripts/kconfig/conf -s arch/x86/Kconfig >> CHK include/linux/version.h >> CHK include/linux/utsrelease.h >> SYMLINK include/asm -> include/asm-x86 >> CC arch/x86/kernel/asm-offsets.s >> In file included from include/linux/sched.h:62, >> from arch/x86/kernel/asm-offsets_64.c:8, >> from arch/x86/kernel/asm-offsets.c:4: >> include/linux/ipipe.h:76:2: error: #error "CONFIG_NR_CPUS is too >> large, please lower it." >> make[1]: *** [arch/x86/kernel/asm-offsets.s] Error 1 >> make: *** [prepare0] Error 2 >> >> >> The CONFIG_NR_CPUS config variable is set to the default 64, but I >> still get this error if I lower it to 4 or 2. (This is a dual-core >> machine, AMD X2.) >> >> I tried commenting-out this error, just to see what would happen, but >> I get an oops on boot. Setting the boot flag earlyprintk=vga shows a >> backtrace, and the crash happens immediately after >> __ipipe_enable_irqdesc, which is in ipipe_virtualize_irq. >> >> I don't know how to proceed from here, does anyone know why >> CONFIG_NR_CPUS is triggering this error? > > Could you post the .config that fails to build? > > Yeah, there is a limitation, normally 96 (IIRC). 2 or 4 CPUs is > definitely far below it. > > Jan
Hello, I finally had the time to investigate more and traced back the error to a variable related to the number of IRQs on the system. I should have previously mentioned that this is a 64-bit system by the way, so I found several related #ifdefs in irq_vector.h and apicnum.h. Anyways, I got the kernel to compile properly after disabling the flag CONFIG_SPARSE_IRQ. This made the CONFIG_NR_CPUS error go away, even after setting it back to 64. Also, it booted successfully, so I am on to the next stage of my project. Although, admittedly I have no idea what the potential consequences of turning off CONFIG_SPARSE_IRQ could be. thanks, Steve _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
