Re: Fixing MTRR smp breakage and suspending sysdevs.

[Nigel Cunningham]

Hi.

On Wed, 2004-10-27 at 13:50, Dmitry Torokhov wrote:
> Well, I understand that ACPI is using semaphore and a GFP_KERNEL, but what
> is the problem with MTRR? I understand that they should be set with IRQ
> off but I highly doibt that enabling IRQ at the end is a requirement.
> I think what is described in the commnet is rather a "normal flow of events".

The real problem with MTRRs is SMP support: smp_call_function doesn't
like IRQs disabled.

I got around a similar issue with saving CPU state (for suspend-to-disk)
by using the same general sequence that I later discovered described in
arch/i386/kernel/cpu/mtrr/main.c (set_mtrr header) for saving CPU
contexts. I extended it yesterday to do the MTRR settings as well,
before Shaohua pointed to the more general need.

Regards,

Nigel
-- 
Nigel Cunningham
Pastoral Worker
Christian Reformed Church of Tuggeranong
PO Box 1004, Tuggeranong, ACT 2901

Everyone lives by faith. Some people just don't believe it.
Want proof? Try to prove that the theory of evolution is true.

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