Messages in this thread | | | Date | Fri, 2 Apr 2004 12:54:06 +0200 (CEST) | From | "Maciej W. Rozycki" <> | Subject | Re: [ACPI] Re: Linux 2.4.26-rc1 (cmpxchg vs 80386 build) |
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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 + - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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