Re: [tip:x86/pat] x86: Relegate CONFIG_PAT and CONFIG_MTRR configurabilityto EMBEDDED

From: H. Peter Anvin
Date: Mon Oct 12 2009 - 13:34:45 EST


On 10/12/2009 04:10 AM, tip-bot for Arjan van de Ven wrote:
> Commit-ID: c03cb3149daed3e411657e3212d05ae27cf1a874
> Gitweb: http://git.kernel.org/tip/c03cb3149daed3e411657e3212d05ae27cf1a874
> Author: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
> AuthorDate: Sun, 11 Oct 2009 10:33:02 -0700
> Committer: Ingo Molnar <mingo@xxxxxxx>
> CommitDate: Mon, 12 Oct 2009 13:06:57 +0200
>
> x86: Relegate CONFIG_PAT and CONFIG_MTRR configurability to EMBEDDED
>
> MTRR and PAT support (which got added to CPUs over 10 years ago)
> are no longer really optional in that more and more things are
> depending on PAT just working, including various drivers and newer
> versions of X. (to not even speak of MTRR)
>
> Having this as a regular config option just no longer makes sense.
>
> This patch relegates CONFIG_X86_PAT to the EMBEDDED category so
> ultra-embedded can still disable it if they really need to.
>

Should we combine this with removing the whitelist (which is largely
vestigial at this point) and replace it with a blacklist (possibly
empty)? I still haven't seen any evidence that there are any CPUs which
have problems, and PAT support go back all the way to Pentium III -- and
page table attributes can be used all the way back to 386, it just
excludes the WC type.

-hpa
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