Re: strange MTRR on 2.6.29-git

From: Ingo Molnar
Date: Sun Apr 05 2009 - 09:41:48 EST



* Meelis Roos <mroos@xxxxxxxx> wrote:

> > > reg00: base=0x000000000 (    0MB), size=  512MB, count=1: write-back
> > > reg01: base=0x020000000 (  512MB), size=    1MB, count=1: write-back
> > > reg02: base=0x020000000 (  512MB), size=    1MB, count=1: uncachable
> > > reg03: base=0x0f2000000 ( 3872MB), size=   32MB, count=2: write-combining
> > > reg04: base=0x0f8000000 ( 3968MB), size=   64MB, count=1: write-combining
>
> > that is original setting by BIOS.
> > it should be ok.
> > if you like, could try to enable
> >
> > CONFIG_MTRR=y
> > CONFIG_MTRR_SANITIZER=y
> > CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=1
> > CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
> >
> > it could do the clean up for you.
>
> Thank you, it did clean it up:
>
> reg00: base=0x000000000 ( 0MB), size= 512MB, count=1: write-back
> reg01: base=0x0f2000000 ( 3872MB), size= 32MB, count=2: write-combining
> reg02: base=0x0f8000000 ( 3968MB), size= 64MB, count=1: write-combining
>
> and it removed the overlapping MTRR-s altogether since there was
> no RAM described t be here. Seems to work fine.

ok, great.

I'm wondering whether CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT should be
1 by default in the future.

Ingo
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