Messages in this thread | | | From | Con Kolivas <> | Subject | Re: interactive task starvation | Date | Wed, 22 Mar 2006 00:13:15 +1100 |
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On Wednesday 22 March 2006 00:10, Mike Galbraith wrote: > On Tue, 2006-03-21 at 22:53 +1100, Con Kolivas wrote: > > On Tuesday 21 March 2006 22:18, Ingo Molnar wrote: > > > great work by Mike! One detail: i'd like there to be just one default > > > throttling value, i.e. no grace_g tunables [so that we have just one > > > default scheduler behavior]. Is the default grace_g[12] setting good > > > enough for your workload? > > > > I agree. If anything is required, a simple on/off tunable makes much more > > sense. Much like I suggested ages ago with an "interactive" switch which > > was rather unpopular when I first suggested it. > > Let me try to explain why on/off is not sufficient. > > You notice how Willy said that his notebook is more responsive with > tunables set to 0,0? That's important, because it's absolutely true... > depending what you're doing. Setting tunables to 0,0 cuts off the idle > sleep logic, and the sleep_avg divisor - both of which were put there > specifically for interactivity - and returns the scheduler to more or > less original O(1) scheduler. You and I both know that these are most > definitely needed in a Desktop environment. For instance, if Willy > starts editing code in X, and scrolls while something is running in the > background, he'll suddenly say hey, maybe this _ain't_ more responsive, > because all of a sudden the starvation added with the interactivity > logic will be sorely missed as my throttle wrings X's neck. > > How long should Willy be able to scroll without feeling the background, > and how long should Apache be able to starve his shell. They are one > and the same, and I can't say, because I'm not Willy. I don't know how > to get there from here without tunables. Picking defaults is one thing, > but I don't know how to make it one-size-fits-all. For the general > case, the values delivered will work fine. For the apache case, they > absolutely 100% guaranteed will not.
So how do you propose we tune such a beast then? Apache users will use off, everyone else will have no idea but to use the defaults.
Cheers, Con - 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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