Re: [PATCH v2] x86: mtrr: don't modify RdDram/WrDram bits of fixedMTRRs

From: Ingo Molnar
Date: Thu Mar 12 2009 - 21:59:44 EST



* Andreas Herrmann <andreas.herrmann3@xxxxxxx> wrote:

> Impact: bug fix + BIOS workaround

> Change to previous version:
> I slightly modified the log message (e.g. addition of FW_WARN).
>
> Please consider to apply this patch for .29.

i've applied it to tip:x86/mtrr, thanks Andreas.

I've add a -stable backport tag - so if it's problem-free it
should show up in .29.1.

It is not completely clear what the impact of this fix is. What
types of problems are such incoherent MTRR settings causing in
practice? Boot hang? S2RAM failures? Performance problems?

Without knowing the exact impact we cannot apply it this late in
the .29.0 cycle - and MTRR code change are dangerous in any case
so even if we knew the exact scope and impact we'd probably not
do it in .29.

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/