Messages in this thread | | | Date | Tue, 5 Aug 2003 15:16:08 +1000 | From | Con Kolivas <> | Subject | Re: [PATCH] O13int for interactivity |
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Quoting Nick Piggin <piggin@cyberone.com.au>:
> Con Kolivas wrote: > > >Quoting Nick Piggin <piggin@cyberone.com.au>: > > > > > >> > >>Con Kolivas wrote: > >> > >> > >>>On Tue, 5 Aug 2003 12:21, Nick Piggin wrote: > >>> > >>> > >>>>No, this still special-cases the uninterruptible sleep. Why is this > >>>>needed? What is being worked around? There is probably a way to > >>>>attack the cause of the problem. > >>>> > >>>> > >>>Footnote: I was thinking of using this to also _elevate_ the dynamic > >>> > >>priority > >> > >>>of tasks waking from interruptible sleep as well which may help > throughput. > >>> > >>> > >>Con, an uninterruptible sleep is one which is not be woken by a signal, > >>an interruptible sleep is one which is. There is no other connotation. > >>What happens when read/write syscalls are changed to be interruptible? > >>I'm not saying this will happen... but come to think of it, NFS probably > >>has interruptible read/write. > >> > >>In short: make the same policy for an interruptible and an uninterruptible > >>sleep. > >> > > > >That's the policy that has always existed... > > > >Interesting that I have only seen the desired effect and haven't noticed any > > >side effect from this change so far. I'll keep experimenting as much as > >possible (as if I wasn't going to) and see what the testers find as well. > > > > Oh, I'm not saying that your change is outright wrong, on the contrary I'd > say you have a better feel for what is needed than I do, but if you are > finding > that the uninterruptible sleep case needs some tweaking then the same tweak > should be applied to all sleep cases. If there really is a difference, > then its > just a fluke that the sleep paths in question use the type of sleep you are > testing for, and nothing more profound than that.
Ah I see. It was from my observations of the behaviour of tasks in D that found it was the period spent in D that was leading to unfairness. The same tweak can't be applied to the rest of the sleeps because that inactivates everything. So it is a fluke that the thing I'm trying to penalise is what tasks in uninterruptible sleep do, but it is by backward observation of D tasks, not random chance.
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