Re: [ACPI] Re: Linux 2.4.26-rc1 (cmpxchg vs 80386 build)

From: Jamie Lokier
Date: Wed Mar 31 2004 - 10:05:24 EST


Maciej W. Rozycki wrote:
> Well, "cmpxchg", "xadd", etc. can be easily emulated with an aid of a
> spinlock. With SMP operation included.

Nope. Len Brown wrote:

> Linux uses this locking mechanism to coordinate shared access
> to hardware registers with embedded controllers,
> which is true also on uniprocessors too.

You can't do that with a spinlock. The embedded controllers would
need to know about the spinlock.

-- Jamie
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