>
> Hello all,
>
> Are there any patches available to enable some sort of CPU affinity? this
> would be useful for some software (e.g. Informix Dynamic Server) and in
> general would reduce cache thrashing on SMP boxes.
Linux already uses a simple form of CPU affinity. Although it is quite
simple, it is quite effective. I worked on it for about a week somewhere
around 2.1.4x and was unable to acheve any intresting improvements.
With more complicated schemes I had the following problems:
1) The added computation time outweighed the benifit.
2) The 'smart' method slowed cpu load imbalance rebalencing and slowed
things down.
or
3) It broke even.
However, this was on a Dual P5/166MMX with a combined L2 cache. On PPRO+
the L2 caches are seperate so better affinity gives you a bigger win. I
havn't done any expirmentation on PPRO+ SMP systems, so it might be a win
there...
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