Re: [patch] CONFIG_NR_CPUS

Thomas 'Dent' Mirlacher (dent@cosy.sbg.ac.at)
Thu, 6 Jun 2002 23:23:11 +0200 (MET DST)


--snip/snip

> OK. What I'll do is:
>
> #ifdef CONFIG_SMP
> #define NR_CPUS CONFIG_NR_CPUS
> #else
> #define NR_CPUS 1
> #endif
>
> and then go edit every SMP-capable arch's config.in/Config.help
> files. But the arch maintainers should test one case please - x86
> was locking up at boot on quad CPU with NR_CPUS=2. Others may do
> the same.

well, what you need to do is make sure smp_num_cpu <= NR_CPUS,
otherwise the kernel will go ballistic on several places within
the code.

- at least in the network system there is the assumption, that
NR_CPUS is the upper limit of cpus. after initialization, everything
uses smp_num_cpus, which is a nice thing for cpu-hotplugging :)

tm

-- 
in some way i do, and in some way i don't.

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