Re: Calling current() from interrupt context

From: David S. Miller (
Date: Mon Oct 09 2000 - 17:39:22 EST

   Date: Tue, 10 Oct 2000 00:44:58 +0200
   From: "Andi Kleen" <>

   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.

David S. Miller
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

This archive was generated by hypermail 2b29 : Sun Oct 15 2000 - 21:00:14 EST