Messages in this thread | | | Date | Wed, 18 Apr 2007 13:27:55 -0600 | From | "Chris Friesen" <> | Subject | Re: [ck] Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS] |
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Mark Glines wrote:
> One minor question: is it even possible to be completely fair on SMP? > For instance, if you have a 2-way SMP box running 3 applications, one of > which has 2 threads, will the threaded app have an advantage here? (The > current system seems to try to keep each thread on a specific CPU, to > reduce cache thrashing, which means threads and processes alike each > get 50% of the CPU.)
I think the ideal in this case would be to have both threads on one cpu, with the other app on the other cpu. This gives inter-process fairness while minimizing the amount of task migration required.
More interesting is the case of three processes on a 2-cpu system. Do we constantly migrate one of them back and forth to ensure that each of them gets 66% of a cpu?
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