On Tue, Aug 20, 2013 at 4:47 AM, Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > --- a/kernel/time/Kconfig > +++ b/kernel/time/Kconfig > @@ -157,6 +157,33 @@ config NO_HZ_FULL_SYSIDLE > > Say N if you are unsure. > > +config NO_HZ_FULL_SYSIDLE_SMALL > + int "Number of CPUs above which large-system approach is used" > + depends on NO_HZ_FULL_SYSIDLE > + range 1 NR_CPUS This causes "kernel/time/Kconfig:162:warning: range is invalid" on m68k and all other architectures that do not support SMP. How to reproduce: make ARCH=m68k defconfig Furthermore, it seems only hexagon, metag, mips, and x86 set NR_CPUS to 1 if !SMP. On other architectures, NR_CPUS is not defined and presumed to be 0. Hence in non-interactive configs (e.g. "make defconfig"), NO_HZ_FULL_SYSIDLE_SMALL will end up as 0. In interactive configs (e.g. "make oldconfig") Kconfig suggest "0" as the default, but refuses to accept it as it doesn't fall within the range 1..0. How to reproduce: Remove the "depends on NO_HZ_FULL_SYSIDLE" make ARCH=powerpc mpc83xx_defconfig grep NO_HZ_FULL_SYSIDLE_SMALL .config -> CONFIG_NO_HZ_FULL_SYSIDLE_SMALL=0 sed 's/CONFIG_NO_HZ_FULL_SYSIDLE_SMALL=0//g' -i .config make ARCH=powerpc oldconfig -> no value is accepted Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html