Re: [PATCH] arch/arm/kernel: use cpu_relax() in halt loops

[Russell King - ARM Linux]

On Tue, Dec 14, 2010 at 11:48:48PM +0100, Jonathan Neuschäfer wrote:
> Looking throught arch/arm/kernel/ I found some halt loops.
> I just thought we could save some power here using cpu_relax(),
> or am I missing something?

#if __LINUX_ARM_ARCH__ == 6
#define cpu_relax()                     smp_mb()
#else
#define cpu_relax()                     barrier()
#endif

IOW, it's either a memory barrier or compiler barrier on ARM; it
doesn't do any power saving.
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