• Dario Faggioli's avatar
    sched/deadline: Add SCHED_DEADLINE inheritance logic · 2d3d891d
    Dario Faggioli authored
    Some method to deal with rt-mutexes and make sched_dl interact with
    the current PI-coded is needed, raising all but trivial issues, that
    needs (according to us) to be solved with some restructuring of
    the pi-code (i.e., going toward a proxy execution-ish implementation).
    This is under development, in the meanwhile, as a temporary solution,
    what this commits does is:
     - ensure a pi-lock owner with waiters is never throttled down. Instead,
       when it runs out of runtime, it immediately gets replenished and it's
       deadline is postponed;
     - the scheduling parameters (relative deadline and default runtime)
       used for that replenishments --during the whole period it holds the
       pi-lock-- are the ones of the waiting task with earliest deadline.
    Acting this way, we provide some kind of boosting to the lock-owner,
    still by using the existing (actually, slightly modified by the previous
    commit) pi-architecture.
    We would stress the fact that this is only a surely needed, all but
    clean solution to the problem. In the end it's only a way to re-start
    discussion within the community. So, as always, comments, ideas, rants,
    etc.. are welcome! :-)
    Signed-off-by: default avatarDario Faggioli <raistlin@linux.it>
    Signed-off-by: default avatarJuri Lelli <juri.lelli@gmail.com>
    [ Added !RT_MUTEXES build fix. ]
    Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
    Link: http://lkml.kernel.org/r/1383831828-15501-11-git-send-email-juri.lelli@gmail.com
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
deadline.c 40.5 KB