On Tuesday 13 March 2007 02:26, Linus Torvalds wrote: > On Mon, 12 Mar 2007, Mike Galbraith wrote: > > On Mon, 2007-03-12 at 22:23 +1100, Con Kolivas wrote: > > > Mike the cpu is being proportioned out perfectly according to fairness > > > as I mentioned in the prior email, yet X is getting the lower latency > > > scheduling. I'm not sure within the bounds of fairness what more would > > > you have happen to your liking with this test case? > > > > It has been said that "perfection is the enemy of good". The two > > interactive tasks receiving 40% cpu while two niced background jobs > > receive 60% may well be perfect, but it's damn sure not good. > > Well, the real problem is really "server that works on behalf of somebody > else". > > X is just the worst *practical* example of this, since not only is it the > most common such server, it's also a case where people see interactive > issues really easily. > > And the problem is that a lot of clients actually end up doing *more* in > the X server than they do themselves directly. Doing things like showing a > line of text on the screen is a lot more expensive than just keeping track > of that line of text, so you end up with the X server easily being marked > as getting "too much" CPU time, and the clients as being starved for CPU > time. And then you get bad interactive behaviour. > > So "good fairness" really should involve some notion of "work done for > others". It's just not very easy to do..
Instead of assuming it's bad, have you tried RSDL for yourself? Mike is using 2 lame threads for his test case. -- -ck - 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/
