Messages in this thread | | | Date | Sat, 27 Dec 2003 00:03:00 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH] 2.6.0 batch scheduling, HT aware |
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Hi!
> > > >>>I discussed this with Ingo and that's the sort of thing we thought of. > > > >>>Perhaps a relative crossover of 10 dynamic priorities and an absolute > > > >>>crossover of 5 static priorities before things got queued together. > > > >>> This is really only required for the UP HT case. > > > >> > > > >>Well I guess it would still be nice for "SMP HT" as well. Hopefully the > > > >>code can be generic enough that it would just carry over nicely. > > > > > > > >I disagree. I can't think of a real world scenario where 2+ physical > > > > cpus would benefit from this. > > > > > > Well its the same problem. A nice -20 process can still lose 40-55% of > > > its performance to a nice 19 process, a figure of 10% is probably too > > > high and we'd really want it <= 5% like what happens with a single > > > logical processor. > > > > I changed my mind just after I sent that mail. 4 physical cores running > > three nice 20 and one nice -20 task gives the nice -20 task only 25% of the > > total cpu and 25% to each of the nice 20 tasks. > > Err that should read 4 logical cores.
Actually, for 4 physical cores it is going to be true, too. And if you are memory-bound, stopping those 3 task can speed your important task, too. Its really same. Pavel -- When do you have a heart between your knees? [Johanka's followup: and *two* hearts?] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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