Re: HT and idle = poll

Linus Torvalds (torvalds@transmeta.com)
Thu, 6 Mar 2003 12:05:48 -0800 (PST)


On Thu, 6 Mar 2003, Davide Libenzi wrote:
>
> Not only. The polling CPU will also shoot a strom of memory requests,
> clobbering the CPU's memory I/O stages.

Well, that would only be true with a really crappy CPU with no caches.

Polling the same location (as long as it's a pure poll, not trying to do
some locked read-modify-write cycle) should be fine. At least for
something like idle-polling, where the one location it _is_ polling should
not actually be touched by anybody else until the wakeup actually happens.

Linus

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