From: Ingo M. <mi...@el...> - 2003-01-20 09:24:34
|
On Sun, 19 Jan 2003, Erich Focht wrote: > The results: > - kernbench UserTime is best for the 2.5.59 scheduler (623s). IngoB0 > best value 627.33s for idle=20ms, busy=2000ms. > - hackbench: 2.5.59 scheduler is significantly better for all > measurements. > > I suppose this comes from the fact that the 2.5.59 version has the > chance to load_balance across nodes when a cpu goes idle. No idea what > other reason it could be... Maybe anybody else? this shows that agressive idle-rebalancing is the most important factor. I think this means that the unification of the balancing code should go into the other direction: ie. applying the ->nr_balanced logic to the SMP balancer as well. kernelbench is the kind of benchmark that is most sensitive to over-eager global balancing, and since the 2.5.59 ->nr_balanced logic produced the best results, it clearly shows it's not over-eager. hackbench is one that is quite sensitive to under-balancing. Ie. trying to maximize both will lead us to a good balance. Ingo |