Messages in this thread | | | Date | Tue, 29 Jun 2004 14:36:38 +1000 | From | Nick Piggin <> | Subject | Re: [PATCH] Staircase scheduler v7.4 |
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Felipe Alfaro Solana wrote: > On Mon, 2004-06-28 at 22:11 +1000, Con Kolivas wrote: > > >>The design of staircase would make renicing normal interactive things >>- -ve values bad for the latency of other nice 0 tasks s is not >>recommended for X or games etc. Initial scheduling latency is very >>dependent on nice value in staircase. If you set a cpu hog to nice -5 it >>will hurt audio at nice 0 and so on. Nicing latency unimportant things >>with +ve values is more useful with this design. If you run X and >>evolution at the same nice value they will get equal cpu share for >>example so moving windows means redrawing evolution and X moving get >>equal cpu. Nicing evolution +ve will make X smoother compared to >>evolution redrawing and so on... > > > OK, just a few thoughts... > > 1. Both -mm3 and -np2 suffer from delays when redrawing "damaged" > windows (windows which were covered and now are being exposed): while > moving heavily a window over the screen, "damaged" windows are not > redrawn. I would say this is a sign of starvation. However, this does > not happen with -ck3 that is able to redraw "damaged' windows even while > heavily moving a window all over the screen. > > I can see this by looking at some icons that are lying on my desktop. > With -mm3 and -np2, they are hardly redrawn while heavily moving a > window all around. With -ck3, I can see the icons and their respective > labels all the time. > > 2. Both -mm3 and -np2 show a very smooth behavior when moving windows > all around the screen. However, -ck3 is somewhat a little bit jerky. I > think this is a consequence of point number 1. >
Try having X at a lower priority (higher nice) and it shouldn't get as much of the CPU. I think this is really a fundamental tradeoff that you can't do much about.
> 3. Both -mm3 and -ck3 are inmune to CPU hogs when mantaining > interactivity: running "while true; do a=2; done" doesn't seem to affect > the interactive behavior of them. I check this by running this CPU hog > and hovering my mouse over KXDocker, which is a nice applet for KDE > similar to the Mac OS X docker. KXDocker is another CPU hog by itself, > but plays nicely with the "while true" loop. However, -np2 seems to > suffer a little bit from starvation, as KXDocker animations don't feel > smooth. >
Hmm, in that case bash should go straight down to lowest priority, so it shouldn't impact too much on others' CPU usage... I'll see what I can do though, timeslices could still be a little too big. - 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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