Re: [patch 4/21] fix ARCH_HAS_PREFETCH

H. Peter Anvin (hpa@zytor.com)
Wed, 14 Aug 2002 18:28:05 -0700


Alan Cox wrote:
> On Wed, 2002-08-14 at 21:58, H. Peter Anvin wrote:
>
>>Since some processors now have "busy wait delay" instructions, this
>>would also make it possible to do:
>
>
> Nobody should be using an empty busy loop. If its a short timed busy
> loop then they should be using udelay, if its a long one
> schedule_timeout()
>

Indeed.

> If its polling hardware then it isnt an empty loop

True indeed as well, although we should still have a busy_wait(); macro
that can insert whatever hint instruction the architecture might or
might not have.

-hpa

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