From 2d3d891d3344159d5b452a645e355bbe29591e8b Mon Sep 17 00:00:00 2001 From: Dario Faggioli Date: Thu, 7 Nov 2013 14:43:44 +0100 Subject: sched/deadline: Add SCHED_DEADLINE inheritance logic 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: Dario Faggioli Signed-off-by: Juri Lelli [ Added !RT_MUTEXES build fix. ] Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1383831828-15501-11-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar --- include/linux/sched.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux/sched.h') diff --git a/include/linux/sched.h b/include/linux/sched.h index 9ea15019a5b6..13c53a99920f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1124,8 +1124,12 @@ struct sched_dl_entity { * @dl_new tells if a new instance arrived. If so we must * start executing it with full runtime and reset its absolute * deadline; + * + * @dl_boosted tells if we are boosted due to DI. If so we are + * outside bandwidth enforcement mechanism (but only until we + * exit the critical section). */ - int dl_throttled, dl_new; + int dl_throttled, dl_new, dl_boosted; /* * Bandwidth enforcement timer. Each -deadline task has its @@ -1359,6 +1363,8 @@ struct task_struct { struct rb_node *pi_waiters_leftmost; /* Deadlock detection and priority inheritance handling */ struct rt_mutex_waiter *pi_blocked_on; + /* Top pi_waiters task */ + struct task_struct *pi_top_task; #endif #ifdef CONFIG_DEBUG_MUTEXES -- cgit v1.2.3