Re: [RFC] Implementing temporal affinity

From: Stuart MacDonald (stuartm@connecttech.com)
Date: Fri Aug 25 2000 - 13:43:20 EST


From: "Chris Swiedler" <ceswiedler@mindspring.com>
> > Let's say the minimum time is 50 cycles:
> >
> > Process A last_cpu = 1
> > Process B last_cpu = 1
> > Process C last_cpu = 1
> >
> > Process C runs for 200 cycles on CPU 1
> > Process C last_cpu = 1
> > Process A runs for 300 cycles on CPU 2
> > Process A last_cpu = 2
> >
> > Process C is running on CPU 1
> > Process C last_cpu = 1
> > Process B runs for 15 cycles on CPU 2 but is interrupted
> > Process B last_cpu = 1 (unaltered)
> >
> > Here we have:
> > Process A last_cpu = 2
> > Process B last_cpu = 1
> > Process C last_cpu = 1
> > C is currenty running on 1
> > Scheduler needs to pick a process for 2
> > A runs on 2
> >
> > C is starved
>
> ??? I don't see how C is starved. C and B have an equal chance of being
> scheduled for CPU 1 (barring other factors). Certainly, C won't be starved
> in an extreme sense, because we're only adjusting the goodness(), and so
> eventually it will be scheduled again.

Sorry, typo. B is starved. C is already running on 1
and has 185 cycles left.

Also, I meant starved in that even though B is the
process time-affinity scheduling should choose, it
won't get chosen.

..Stu

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