Messages in this thread | | | Date | Fri, 6 Sep 2013 20:50:41 +0200 | Subject | Re: [PATCH tip/core/rcu 8/9] nohz_full: Add full-system-idle state machine | From | Geert Uytterhoeven <> |
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On Fri, Sep 6, 2013 at 7:30 PM, Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote: >> 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. > > Would it make sense to require that NR_CPUS=1 for !SMP?
Yes, this looks reasonable to me.
> I tried creating a NR_CPUS_REALLY as follows: > > config NR_CPUS_REALLY > int "Fixed version of NR_CPUS" > default NR_CPUS if NR_CPUS > default 1 if !NR_CPUS > > But this still gave a warning on the first "default" even though it > was not in effect. I also tried using Kconfig "if":
IIRC, it tries to use the first default first, so the below may work (the "if SMP" is probably not needed):
config NR_CPUS_REALLY int "Fixed version of NR_CPUS" default 1 if !SMP default NR_CPUS if SMP
> Defining NR_CPUS=1 if !SMP is looking pretty good to me just now. > This would probably have other benefits -- I cannot be the only > person who ever wanted this. ;-)
Sure. I just didn't want to create patches for all architectures without having a discussion first.
And it would be nice if it cuould be done in a central place, without touching all architectures.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
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
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