Re: oops/warning report for the week of November 26, 2008

From: Arjan van de Ven
Date: Thu Nov 27 2008 - 15:27:16 EST


On Thu, 27 Nov 2008 21:18:36 +0100
Ingo Molnar <mingo@xxxxxxx> wrote:

>
> * Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> wrote:
>
> > Ingo Molnar wrote:
> >> * Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> wrote:
> >>
> >>> Rank 8: mtrr_trim_uncached_memory (warning)
> >>> Reported 227 times (619 total reports)
> >>> There is a high number of machines where our MTRR checks
> >>> trigger. I suspect we are too picky in accepting the MTRR
> >>> configuration.
> >>
> >> the warning here means: "the BIOS messed up but we fixed it up for
> >> you just fine".
> >
> > I don't believe that right now. we see so many of these, including
> > many "there's no MTRRs at all", that I am seriously suspecting that
> > our code is just incorrect somehow and triggering too much.
>
> well we looked at existing reports and Linux was right to fix them
> up. Show us one that is incorrect, then we can fix it up.
>
> the "no MTRR's" are vmware/(also qemu?) guests not implementing a
> full CPU emulation.

... and it's still our fault in part, since we don't even check to see
if a cpu claims to support MTRR before complaining about it...

easy to fix though: