Messages in this thread | | | Date | Thu, 6 Mar 2003 12:08:43 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: HT and idle = poll |
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On 6 Mar 2003, Alan Cox wrote: > On Thu, 2003-03-06 at 19:30, Linus Torvalds wrote: > > >So, don't use idle=poll with HT when you know your workload has idle time! I > > >have not tried oprofile, but it stands to reason that this would be a > > idle=poll probably needs to be doing "rep nop" in a tight loop.
We already do that. It's not enough. The HT thing will still steal cycles continually, since the "rep nop" is really only equivalent to a "sched_yield()".
Think of "rep nop" as yielding, and "mwait" as a true wait.
(I don't actually have any real information on "mwait", so I may be wrong about the details on the new instructions. They looked obvious enough, though).
Linus
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