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SubjectRe: [ACPI] Re: Linux 2.4.26-rc1 (cmpxchg vs 80386 build)
On Thu, 1 Apr 2004, Len Brown wrote:

> ACPI specifies a location in regular memory that is used to contain the
> lock. The lock is used both by the CPU and by the embedded controller
> to cover access to shared registers. We don't spin on this lock because
> we don't know how long the embedded controller might hold it. Instead
> when we fail to acquire it we schedule an event to trigger when the lock
> is free.

OK, that's clear to me now. Then does this lock really require
"cmpxchg"? Wouldn't a lone "xchg" suffice?

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +
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