Re: [RFC Patch]Use ar.kr2 for smp_processor_id

From: <peterc_at_gelato.unsw.edu.au>
Date: 2007-02-08 19:28:55
>>>>> "Zou" == Zou Nan hai <nanhai.zou@intel.com> writes:

Zou> Pin ar.kr2 of each CPU, so that smp_processor_id can use it.
Zou> This will save some memory foot-print when smp_procerror_id() is
Zou> called.

Accessing ar.k? takes 12 cycles... it's faster in the kernel to
use current_thread_info()->cpu which if cache hot can be done in two
cycles.

--
Dr Peter Chubb  http://www.gelato.unsw.edu.au  peterc AT gelato.unsw.edu.au
http://www.ertos.nicta.com.au           ERTOS within National ICT Australia
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Received on Thu Feb 08 21:29:40 2007

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