|To:||Peter Zijlstra <firstname.lastname@example.org>|
|Subject:||[RFC 0/12][PATCH] SCHED_DEADLINE (new version of SCHED_EDF)|
|Date:||Fri, 16 Oct 2009 17:35:24 +0200|
|Cc:||email@example.com, linux-kernel <firstname.lastname@example.org>, michael trimarchi <email@example.com>, Fabio Checconi <firstname.lastname@example.org>, Ingo Molnar <email@example.com>, Thomas Gleixner <firstname.lastname@example.org>, Dhaval Giani <email@example.com>, Johan Eker <firstname.lastname@example.org>, "p.faure" <email@example.com>, Chris Friesen <firstname.lastname@example.org>, Steven Rostedt <email@example.com>, Henrik Austad <firstname.lastname@example.org>, Frederic Weisbecker <email@example.com>, Darren Hart <firstname.lastname@example.org>, Sven-Thorsten Dietrich <email@example.com>, Bjoern Brandenburg <firstname.lastname@example.org>, Tommaso Cucinotta <email@example.com>, "giuseppe.lipari" <firstname.lastname@example.org>, Juri Lelli <email@example.com>|
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... - 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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