|To:||Peter Zijlstra <firstname.lastname@example.org>|
|Subject:||[RFC][PATCH 00/22] sched: SCHED_DEADLINE v3|
|Date:||Fri, 29 Oct 2010 08:18:47 +0200|
|Cc:||Ingo Molnar <email@example.com>, Thomas Gleixner <firstname.lastname@example.org>, Steven Rostedt <email@example.com>, Chris Friesen <firstname.lastname@example.org>, email@example.com, Frederic Weisbecker <firstname.lastname@example.org>, Darren Hart <email@example.com>, Johan Eker <firstname.lastname@example.org>, "p.faure" <email@example.com>, linux-kernel <firstname.lastname@example.org>, Claudio Scordino <email@example.com>, michael trimarchi <firstname.lastname@example.org>, Fabio Checconi <email@example.com>, Tommaso Cucinotta <firstname.lastname@example.org>, Juri Lelli <email@example.com>, Nicola Manica <firstname.lastname@example.org>, Luca Abeni <email@example.com>, Dhaval Giani <firstname.lastname@example.org>, Harald Gustafsson <email@example.com>, paulmck <firstname.lastname@example.org>, Dario <email@example.com>|
Hello everyone, This is the take 3 for the SCHED_DEADLINE patchset. I've done my best to have something that can be publicly shown by the Kernel Summit. To be sincere, I didn't make in getting the code to the point I wanted to but, hey, I hope this can be at least something from where to start the discussion. :-) BTW, the patchset introduces a new deadline based real-time task scheduling policy --called SCHED_DEADLINE-- with bandwidth isolation (aka "resource reservation") capabilities. It now supports global/clustered multiprocessor scheduling through dynamic task migrations. The code is being jointly developed by ReTiS Lab (http://retis.sssup.it) and Evidence S.r.l (http://www.evidence.eu.com) in the context of the ACTORS EU-funded project (http://www.actors-project.eu). It is also starting to get some users, both in academic and applied research, considered I'm getting some feedback from Ericsson, MIT and from Iowa State, Porto (ISEP), Carnegie Mellon, Barcelona and Trento universities. From the previous release[*]: - all the comments and the fixes coming from the reviews we got have been considered and applied; - global and clustered (e.g., through cpusets) scheduling is now available. This means that tasks can migrate among (a subset of) CPUs when this is needed, by means of pushes & pulls, like in sched_rt.c; - (c)group based task admission logic and bandwidth management has been removed, in favour of a per root_domain tasks bandwidth accounting mechanism; - finally, all the code underwent major restructuring (many parts have been almost completely rewritten), to make it easier to read and understand, as well as more consistent with kernel mechanisms and conventions; Still missing/incomplete: - (c)group based bandwidth management, and maybe scheduling. It seems some more discussion on what precisely we want is *really* needed for this point; - better handling of rq selection for dynamic task migration, by means of a cpupri equivalent for -deadline tasks. Not that hard to do, we already have some ideas and hope to have the code soon; - bandwidth inheritance (to replace deadline/priority inheritance). What's in the patchset is just very few more than a simple placeholder. I tried doing something that may fit in the current architecture of rt_mutexes (i.e., the pi-chain of waiters) but did not get to anything meaningful. We are now working on migrating to something similar to what it's probably known here as proxy execution... It's not easy at all, but we are on it. :-) The official page of the project is: http://www.evidence.eu.com/sched_deadline.html while the development is taking place at: http://gitorious.org/sched_deadline/pages/Home http://gitorious.org/sched_deadline Check the repositories frequently if you're interested, and feel free to e-mail me for any issue you run into. Patchset is on top of tip/master (as of today). The git-tree and patches for PREEMPT_RT will be available on the project website in the next days. Relationship of this patchset with the EDF-throttling one is tight, although the two implementations add different (new) features and solve different problems. In case they have to coexist, a lot of code could be shared and duplications would be easily avoided. As usual, any kind of feedback is welcome and appreciated. Thanks in advice and regards, Dario [*] http://lwn.net/Articles/376502, http://lwn.net/Articles/353797 Dario Faggioi, SCHED_DEADLINE (22) sched: add sched_class->task_dead. sched: add extended scheduling interface. sched: SCHED_DEADLINE data structures. sched: SCHED_DEADLINE SMP-related data structures. sched: SCHED_DEADLINE policy implementation. sched: SCHED_DEADLINE handles spacial kthreads. sched: SCHED_DEADLINE push and pull logic. sched: SCHED_DEADLINE avg_update accounting. sched: add period support for -deadline tasks. sched: add a syscall to wait for the next instance. sched: add schedstats for -deadline tasks. sched: add runtime reporting for -deadline tasks. sched: add resource limits for -deadline tasks. sched: add latency tracing for -deadline tasks. sched: add traceporints for -deadline tasks. sched: add SMP traceporints for -deadline tasks. sched: add signaling overrunning -deadline tasks. sched: add reclaiming logic to -deadline tasks. rtmutex: turn the plist into an rb-tree. sched: drafted deadline inheritance logic. sched: add bandwidth management for sched_dl. sched: add sched_dl documentation. Documentation/scheduler/sched-deadline.txt | 147 +++ arch/arm/include/asm/unistd.h | 4 + arch/arm/kernel/calls.S | 4 + arch/x86/ia32/ia32entry.S | 4 + arch/x86/include/asm/unistd_32.h | 6 +- arch/x86/include/asm/unistd_64.h | 8 + arch/x86/kernel/syscall_table_32.S | 4 + include/asm-generic/resource.h | 7 +- include/linux/init_task.h | 10 + include/linux/rtmutex.h | 13 +- include/linux/sched.h | 208 ++++- include/linux/syscalls.h | 9 + include/trace/events/sched.h | 312 +++++- kernel/fork.c | 4 +- kernel/hrtimer.c | 2 +- kernel/posix-cpu-timers.c | 55 + kernel/rtmutex-debug.c | 8 +- kernel/rtmutex.c | 146 ++- kernel/rtmutex_common.h | 22 +- kernel/sched.c | 1046 ++++++++++++++++-- kernel/sched_debug.c | 46 + kernel/sched_dl.c | 1713 ++++++++++++++++++++++++++++ kernel/sched_fair.c | 6 +- kernel/sched_rt.c | 7 +- kernel/sched_stoptask.c | 2 +- kernel/softirq.c | 6 +- kernel/sysctl.c | 14 + kernel/trace/trace_sched_wakeup.c | 44 +- kernel/trace/trace_selftest.c | 31 +- kernel/watchdog.c | 3 +- 30 files changed, 3721 insertions(+), 170 deletions(-) -- <<This happens because I choose it to happen!>> (Raistlin Majere) ---------------------------------------------------------------------- Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy) http://blog.linux.it/raistlin / firstname.lastname@example.org / email@example.com
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