[CentOS] [OT] Memory Models and Multi/Virtual-Cores -- WAS: 4.0 -> 4.1 update failing

Fri Jun 24 13:59:36 UTC 2005
Feizhou <feizhou at graffiti.net>

Bryan J. Smith wrote:

>On Fri, 2005-06-24 at 07:42 -0500, Bryan J. Smith wrote:
>  
>
>>I'll find it.  It was from a gentlemen from AMD that discussed it in a
>>thread right after Intel announced EM64T.  Linus & co. were talking
>>about how EM64T is still using a 32-bit platform underneath.  The AMD
>>gentlemen commented how they a few vendors had a BIOS option "Linux" for
>>the memory access, and the Linux kernel could support linear addressing
>>above 4GB.
>>    
>>
>
>Ack, it doesn't appear to be directly in the 2004Feb17 thread:  
>  http://kerneltrap.org/node/2466  
>
>There are a few comments on how the Athlon differs from Intel because of
>the Alpha EV6, but not the more technical detail I was referring to.
>  
>
http://marc.theaimsgroup.com/?l=linux-kernel&m=107759901509280&w=2

The Linux option in bios is mentioned here.

>Again, to get this "mode" you have to:  
>a)  Tell the BIOS to enable a "Linux" memory mode
>b)  Have a Linux kernel (Linux/x86-64 I believe?) that supports it
>
>Yes, that's a modification of the Linux/x86-64 kernel running on a "32-
>bit" Athlon, because it offers the extended, linear memory addressing
>and other memory management.
>  
>
http://marc.theaimsgroup.com/?l=linux-kernel&m=107757492125437&w=2

I think what Bryan here is talking about is called IOMMU by the kernel guys.