RE: [patch] scheduler bugfix, SMP, 2.4.0-test7

From: Ingo Molnar (mingo@elte.hu)
Date: Tue Aug 29 2000 - 06:04:37 EDT

  • Next message: Andrea Arcangeli: "Re: [patch] waitqueue optimization, 2.4.0-test7"

    On Mon, 28 Aug 2000, Dimitris Michailidis wrote:

    > Speaking of footprints, that reschedule_idle should really be turned into a
    > FASTCALL. It's large and inlining creates too many copies in frequently
    > executed code. __wake_up() even has two of them, check how large it is some
    > time.

    i agree fully. The attached patch against test8-pre1 changes
    schedule_idle() from inline to FASTCALL - things look much nicer with this
    one applied.

    the patch's second half adds the check for need_resched after schedule().
    IMO this is needed not only for (admittedly secondary reason of) latency,
    but for correctness as well: schedule_idle() might have preempted the
    current process (even if both processes are non-idle), so checking for
    need_resched is needed for robustness.

            Ingo


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