Re: [PATCH] Nick's scheduler policy v12

[Nick Piggin <piggin@cyberone.com.au>]

Martin J. Bligh wrote:

>>On Fri, Sep 05, 2003 at 11:54:04AM -0700, Martin J. Bligh wrote:
>>
>>>>Backboost is gone so X really should be at -10 or even higher.
>>>>
>>>Wasn't that causing half the problems originally? Boosting X seemed
>>>to starve xmms et al. Or do the interactivity changes fix xmms
>>>somehow, but not X itself? Explicitly fiddling with task's priorities
>>>seems flawed to me.
>>>
>>Wasn't it the larger timeslices with lower nice values in stock and Con's
>>patches that made X with nice -10 a bad idea?
>>
>
>Debian renices X by default to -10 ... I fixed all my desktop interactivity
>problems around 2.5.63 timeframe by just turning that off. That was way 
>before Con's patches.
>

Yep, as Mike mentioned, renicing X causes it to get bigger
timeslices with the stock scheduler. If you had 2 nice -20 processes,
they would each get a timeslice of 200ms, so you're harming their
latency.

>
>There may be some more details around this, and I'd love to hear them,
>but I fundmantally believe that explitit fiddling with particular
>processes because we believe they're somehow magic is wrong (and so
>does Linus, from previous discussions).
>

Well it would be nice if someone could find out how to do it, but I
think that if we want X to be able to get 80% CPU when 2 other CPU hogs
are running, you have to renice it.