Re: [patch 06/11] x86: nmi_32/64.c - use apic_write_around insteadof apic_write

From: Cyrill Gorcunov
Date: Wed May 28 2008 - 12:04:35 EST


[Maciej W. Rozycki - Wed, May 28, 2008 at 04:35:14PM +0100]
| On Sat, 24 May 2008, Cyrill Gorcunov wrote:
|
| > apic_write_around will be expanded to apic_write in 64bit mode
| > anyway. Only a few CPUs (well, old CPUs to be precise) requires
| > such an action. In general it should not hurt and could be cleaned
| > up for apic_write (just in case)
| >
| > Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
| > ---
|
| Acked-by: Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
|
| Almost all local APIC write accesses must use apic_write_around(). The
| notable exceptions are appropriately guarded accesses to the ESR (there is
| no need ever to write to this register on Pentium processors and a read of
| the register has side-effects) and pieces of code known never to run on
| original Pentium processors.
|
| Maciej
|

Thanks Maciej!

Could you take a look please on

http://lkml.org/lkml/2008/5/26/146

i'm investigateting what is happening (Adrian pointed on
main reason I think) but can't understand why is that.

- Cyrill -
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