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    SubjectRe: fairsched + O(1) process scheduler
    On Tue, Apr 08, 2003 at 02:56:34PM -0400, Hubertus Franke wrote:
    >
    > Antonio, while you are coding here is some additional input.

    Great!

    > By intoducing the user based pending queue and leaking
    > the tasks back into the runqueue based on the per user ticks, you
    > are changing semantics slightly.
    >
    > If the task is reinserted back into the runqueue oit should be
    > reinserted into the expired queue iff and only no
    > expired/active queue switch has happened.
    > Otherwise it should be reinserted into the active list.

    This sounds right :)

    > This will becoe important when we later distinguish between
    > users that have limited share and those that have unlimited.

    Yes, we should push the "p->user->uid == 0" test into the
    send_task_to_user() function then... and later on implement
    a "p->user->unlimited_cpu_share == 1" test.

    > Can be implemented by keeping a per runqueue array switch count
    > and store it with the pending task. On reinsertion, if
    > the task has the same as the current it goes to the expired.
    > If its older than the current, then the task missed the array switch
    > and it should go into the active queue.
    >
    > Also, I don't follow necessarily your reason to put an INTERACTIVE
    > task back on the active queue immediately, rather than going first
    > through the pending queue again.
    >
    > This way, a high priority job with even a small sleep_avg already being
    > declared INTERACTIVE, will continue to suck up cycles beyond its
    > user's limits. This can be as long as 8 secs currently.

    Perhaps I'm not declaring this in any explicit way, but I feel
    that this type of control should only be applied to cpu hogs.

    > Instead, things to consider is to feed these as well through the
    > pending queue and distinguish in the pending queue ?
    > More thoughts required here... I let you know when any of them is
    > successful at my end.

    I'm somewhat deadlocked right now, so I'll have to wait until I have
    some think up some way to make it work as intended.

    Greets, Antonio
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