How to determine the L2 cache size on non-AMD CPUs (automatic page queue color tuning)?

Alexander Leidinger Alexander at
Wed Jun 16 16:56:56 GMT 2004

On Wed, 16 Jun 2004 09:35:40 -0700 (PDT)
John Polstra <jdp at> wrote:

> On 16-Jun-2004 Radek Kozlowski wrote:

> > The latest version of cpuid is from 2002 and at least for my Athlon XP-M 
> > processor it doesn't read the information about L2 cache correctly. 
> > IIRC, for my L2 size it only takes one byte from the beginning of ecx 
> > register, whereas in my case it is stored in two, a.s.o. So I wouldn't 
> > rely on cpuid when it comes to newer CPUs.

If bootverbose prints the cache size correctly (at least on -current), I
already have code which does the right thing for your AMD CPU.

> Yes, but it gives working code that generally shows how to get the
> information.  Here's a link to an Intel document "Intel(R) Processor
> Idientification and the CPUID Instruction" that covers the newer CPUs:

I will have a look at both (the cpuid port and the PDF).


           I'm available to get hired (preferred in .lu).                       Alexander @
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