Re: kernel unable to use more than 2 of 16 CPUs on IntelE5540 (i7)

From: Robert Hancock
Date: Thu Jun 24 2010 - 20:24:14 EST

On 06/24/2010 04:05 PM, Roland Dreier wrote:
Your config seems to have CONFIG_PM and therefore CONFIG_ACPI disabled.
So the kernel is relying on mptable information. Unsurprisingly on a
modern system, that info is probably broken -- since everything would
have been tested with ACPI.

Try turning on CONFIG_ACPI and see if that helps at all.

Indeed, not having ACPI enabled will prevent any multi-core CPU detection. ACPI really has to be enabled for any modern x86 system to work properly.

I'd think that the CONFIG_ACPI really should be defaulted on more strongly - maybe force it on if CONFIG_EMBEDDED isn't set or something..
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