Re: nr_cpu_ids incorrect on AMD Quad-Core Opteron 8380

From: Borislav Petkov
Date: Mon Feb 01 2010 - 10:04:53 EST


On Mon, Feb 1, 2010 at 2:57 PM, Borislav Petkov <petkovbb@xxxxxxxxxxxxxx> wrote:
> On Sun, Jan 31, 2010 at 11:59 PM, zhiyi <zhuang@xxxxxxxxxxxxxx> wrote:
>> My module worked for a kernel 2.6.29 with CONFIG_NR_CPUS=64 on my dual
>> quad-core AMD Opteron. The value of nr_cpu_ids I got from the same module
>> was correct (8).
>
> This could mean that your include/generated/autoconf.h, which is used by
> external modules, is not updated and contains CONFIG_NR_CPUS=8. Do
>
> make mrproper
>
> in your kernel directory by moving your .config out of the way first and
> then rebuild your kernel and external module(s). nr_cpu_ids should pick
> up the updated CONFIG_NR_CPUS value from your .config.

That's actually not necessary - the nr_cpu_ids thing is set at compile
time to CONFIG_NR_CPUS but then capped to a possibly lower value upon
boot depending on the info in the ACPI mptables. Can you please send the
.config and the full dmesg of the quadsocket machine?

Thanks.

--
Regards/Gruss,
Boris
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