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    SubjectRe: [patch] voluntary-preempt-
    On Wed, 18 Aug 2004 14:27:03 +0200
    Ingo Molnar <> wrote:

    > * Florian Schmidt <> wrote:
    > > Hi, it applied against with some offsets and some buzz [?].
    > > Well anyways it compiled fine and the copy_page_range latency is
    > > gone.. Now i also see the extracty entropy thing, too..
    > could you try the attached patch that changes SHA_CODE_SIZE to 3 -
    > does this reduce the latency caused by extract_entropy?

    will do..

    > > Btw: one question: at one point in time the IRQ handlers were in the
    > > SCHED_FIFO scheduling class. Why has this changed?
    > so that they dont starve the audio threads by default - the audio IRQ
    > has to get another priority anyway. Maybe we could try a default
    > SCHED_FIFO prio lower than the typical rt_priority of jackd - e.g. 30?

    Oh, upon rereading the chrt manpage i found out why i failed to set them
    to SCHED_FIFO manually. So it was my error. I thought the
    scheduling of the IRQ handlers was not changable at runtime. Thus my
    question to make them SCHED_FIFO by default.

    Well, i still think they should be SCHED_FIFO by default, so no user
    process that is not itself SCHED_FIFO can starve them [X11 was able to
    starve mouse irq's on my system with the defualt IRQ handlers
    running SCHED_OTHER FWIW]. To make starving of user-SCHED_FIFO processes
    unprobably maybe use a default static prio of 0.

    Afaik jackd uses priorities > 0 for its audio threads when runing
    SCHED_FIFO anyways..

    But since the user will have to tweak his IRQ handlers manually anyways
    [set soundcard irq higher prio than the rest, etc..], it doesn't really
    make a difference.


    Palimm Palimm!

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