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    Subject[RFC 0/12][PATCH] SCHED_DEADLINE (new version of SCHED_EDF)
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    Hi Peter, Hi all,

    Given all the comments and feedback we got, here it is the new version
    of our EDF patch, this time in a split series. :-)

    Special thanks to all the one that gave us any kind of suggestion,
    especially during last RTLWS in Dresden.

    The rationale/motivation for the new scheduler is the same of the first
    e-mail (http://lwn.net/Articles/353797/), thus I only add some new and
    (I think) interesting links:
    - Ericsson posting about SCHED_EDF/DEADLINE
    https://labs.ericsson.com/blog/making-linux-more-real-time

    - The slides we presented at RTLWS in Dresden:
    http://retis.sssup.it/people/faggioli/sched_deadline/rtlw_EDF.pdf

    - Luca Abeni's presentation about using deadline based reservation
    schedulers for IRQ-Threads:
    http://www.disi.unitn.it/~abeni/rtlws-slides.pdf

    Moreover, we moved the project on gitorious.org, therefore:
    http://gitorious.org/sched_deadline

    I am also setting up right now the Wiki section, where you can find some
    more detailed usage instructions, examples and overhead estimation:
    http://gitorious.org/sched_deadline/pages/Home

    Git repositories are up and running, and ready at:
    (mainline)
    git://gitorious.org/sched_deadline/linux-deadline.git sched-deadline

    (sched-devel)
    git://gitorious.org/sched_deadline/linux-deadline.git sched-devel-deadline

    (preempt-rt [*])
    git://gitorious.org/sched_deadline/linux-deadline.git rt-deadline

    The new project homepage is
    http://www.evidence.eu.com/sched_deadline.html

    Here the main changes we did, following what many of you --and mainly
    Peter-- suggested:
    - name changed from SCHED_EDF to SCHED_DEADLINE

    - SCHED_DEADLINE has higher priority than SCHED_FIFO/SCHED_RR

    - flags added in sched_param_ex to signal deadline misses
    (in case of utilization > 100%) and/or budget overruns

    - new sched_*_ex prototypes, with a len field to accomodate the size of
    sched_param_ex, trying to avoid further ABI issues if it changes

    - new syscall sched_wait_interval added. It behaves like clock_nanosleep
    but, for a SCHED_DEADLINE task, it also represent the end of the
    current instance (sched_yield no longer needed)

    - on fork, child starts but with 0 bandwidth (i.e., it does not start! :-D)

    - bug fixing :)

    Any feedback and contribution is welcome.

    Many thanks,

    Dario Faggioli
    Claudio Scordino
    Michael Trimarchi

    [*] porting toward preempt-rt is work in progress. Code is there, but we
    are testing and fixing it, with the help of Luca and Nicola from
    Trento... So don't consider it as the final version!

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