Messages in this thread | | | From | Con Kolivas <> | Subject | Re: 2.6.0-test2-mm3 osdl-aim-7 regression | Date | Thu, 7 Aug 2003 20:01:13 +1000 |
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On Thu, 7 Aug 2003 18:25, Nick Piggin wrote: > >The more frequently you round robin the lower the scheduler latency > > between SCHED_OTHER tasks of the same priority. However, the longer the > > timeslice the more benefit you get from cpu cache. Where is the sweet > > spot? Depends on the hardware and your usage requirements of course, but > > Ingo has empirically chosen 25ms after 50ms seemed too long. Basically > > cache trashing becomes a real problem with timeslices below ~7ms on > > modern hardware in my limited testing. A minor quirk in Ingo's original > > code means _occasionally_ a task will be requeued with <3ms to go. It > > will be interesting to see if fixing this (which O12.2+ does) makes a big > > difference or whether we need to reconsider how frequently (if at all) we > > round robin tasks. > > Why not have it dynamic? CPU hogs get longer timeslices (but of course > can be preempted by higher priorities).
Funny you should say that. Before Ingo merged his A3 changes, that's what my version of them did.
Con
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