Re: [PATCH] printk: use this_cpu_{read|write} api onprintk_pending
From: Christoph Lameter
Date: Fri Nov 26 2010 - 12:27:11 EST
On Fri, 26 Nov 2010, Eric Dumazet wrote:
> Le vendredi 26 novembre 2010 Ã 11:11 -0600, Christoph Lameter a Ãcrit :
>
> > I thought sanity tests do not apply for performance testing scenarios?
> >
>
> CONFIG_DEBUG_PREEMPT
You really enable that option for performance testing?
> > smp_processor_id() is usually a simple per cpu data access and very fast.
> >
>
> Sure, but when its already in a register, its better to use the
> register ;)
Well that increases register pressure in the caller. There may be no need
to handle the current processor number in the caller.