Non-serializing equivalent of CPUID?

spamtrap_at_crayne.org
Date: 11/13/04 

Date: Sat, 13 Nov 2004 01:23:57 +0000 (UTC)

In a multithreaded application I'd like to make a call to get which
processor the each thread is running on. I can use CPUID and get the
APIC id (the first byte of EBX when EAX=1), which gives me exactly what
I want but the CPUID instruction is serializing and isn't that great
for performance.

I see Windows2003 has a system call to get the processor id, so perhaps
there is a non-serializing way to get what I want?
Any hints would be greatly appreciated! Thanks,
Brand