Re: adjust prefetch in free_one_pgd()

From: David Mosberger (davidm@napali.hpl.hp.com)
Date: Fri Aug 02 2002 - 11:38:12 EST


>>>>> On 02 Aug 2002 18:49:27 +0100, Alan Cox <alan@lxorguk.ukuu.org.uk> said:

  Alan> I can't think of anything cachable with nasty side effects we
  Alan> might encounter right now but one day someone will do it just
  Alan> to be annoying.

Cacheable and side-effects don't go together. Even without explicit
software prefetches, most modern CPUs will happily and aggressively
prefetch stuff from cacheable translations.

That's (partly) why we have this strange situation where execution in
virtual address space is actually _faster_ than in physical space,
even though the former involves more work per memory access.

        --david
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