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SubjectRe: Calling current() from interrupt context
   Date: 	Tue, 10 Oct 2000 00:44:58 +0200
From: "Andi Kleen" <ak@suse.de>

On Mon, Oct 09, 2000 at 11:41:13PM +0100, Alan Cox wrote:
> I dont actually know a CPU that doesnt have one in SMP mode. Its just often
> behind an I/O interface that is slower than ideal

Where would you put it for IA32 ? I don't know any free MSR that could
be abused for that, and acessing MSRs is insanely slow anyways. Any
other ideas ?

The local APIC holds the hardware cpu number (which happens to equal
the logical cpu number in the current x86 code). And I believe the
local APIC has a 32-bit scratch register or 2 as well... but don't
quote me on that one.

Later,
David S. Miller
davem@redhat.com
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