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SubjectRe: [RFC][PATCH] linux-2.6.0-test2_mtrr-race-fix_A0
Date

Hi,

You should not remove the barrier past mtrr change. If you do that, it is
possible that cpu's run with inconsistent mtrrs. This can have bad
sideeffects since at least the cache snooping protocol used by intel uses
assumptions about the cachability of memory regions. Those information about
the cachability is also taken from the mtrrs as far as I remember.
This intel cpu developer manual, which documented the early PII and PPro
chips, recommended this algorithm. Since actual intel cpus use the same old
cpu to chipset bus protocol, this old documentation most propably still
applies.

So the conclusion is that as far as you don't know the exact way all those SMP
protocols between chipsets and CPUs with all the possible sideeffects very
well, dont't change this behavour.

But I'm shure that fixes to the stack allocated variable problem are welcome
:)

Greetings

Mathias Fröhlich

--
Mathias Fröhlich, email: Mathias.Froehlich@web.de
old email was: frohlich@na.uni-tuebingen.de

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