Messages in this thread | | | Date | Wed, 12 Jul 2000 22:57:14 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: Report: Big Improvement in -test3 |
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On Wed, 12 Jul 2000, Richard Gooch wrote:
> Linus Torvalds writes: > > > > Heh. > > > > This was actually almost certainly due to a _really_ simple improvement. > > > > As of test4-pre4, the default time-slice for a normal process is just > > 50ms, while it used to be 200ms. > > > > 200ms is way too long a timeslice when working with interactive things: > > it's easily noticeable. 50ms should be much better. > > So is the number of ticks (5 now?) now decoupled from the > goodness/dynamic priority level?
Yes.
If people wondered why the "->priority" -> "->nice" change was done, now you know. "->priority" used to be a tick-based nice level, and it just wasn't able to handle UNIX semantics when the resolution of ticks dropped to just a few ticks.
Simple vulcan mind-trick. Switch them around, and instead of calculating "nice" from the number of ticks, we calculate ticks from the virtual nice value, making the problem go away and allowing for a shorter timeslice without having to do major surgery.
Linus
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