Hi, On Fri, 13 Jul 2007, Mike Galbraith wrote:
> > The new scheduler does _a_lot_ of heavy 64 bit calculations without any > > attempt to scale that down a little... > > See prio_to_weight[], prio_to_wmult[] and sysctl_sched_stat_granularity. > Perhaps more can be done, but "without any attempt..." isn't accurate. Calculating these values at runtime would have been completely insane, the alternative would be a crummy approximation, so using a lookup table is actually a good thing. That's not the problem. BTW could someone please verify the prio_to_wmult table, especially [16] and [21] look a little off, like a digit was cut off. While I'm at this, the 10% scaling there looks a little much (unless there are other changes I haven't looked at yet), the old code used more like 5%. This would mean a prio -20 task would get 98.86% cpu time compared to a prio 0 task, that was previously about the difference between -20 and 19 (and it would have previously gotten only 88.89%), now a prio -20 task would get 99.98% cpu time compared to a prio 19 task. The individual levels are unfortunately not that easily comparable, but at the overall scale the change looks IMHO a little drastic. bye, Roman - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
