Re: [rfc 00/45] [RFC] CPU ops and a rework of per cpu data handling on x86_64

David Miller
2007-11-20T04:04:51Z

From: Andi Kleen <ak@suse.de>
Date: Tue, 20 Nov 2007 04:25:34 +0100

>
> > Although we have a per-cpu area base in a fixed global register
> > for addressing, the above isn't beneficial on sparc64 because
> > the atomic is much slower than doing a:
> >
> > local_irq_disable();
> > nonatomic_percpu_memory_op();
> > local_irq_enable();
>
> Again might be pointing out the obvious, but you
> need of course save_flags()/restore_flags(), not disable/enable().

Right, but the cost is the same for that on sparc64 unlike
x86 et al.