[RFC][PATCH RT 4/4] sched/rt: Initiate a pull when the priority of a task is lowered

From: Steven Rostedt
Date: Fri Dec 07 2012 - 19:09:59 EST


If a task lowers its priority (say by losing priority inheritance)
if a higher priority task is waiting on another CPU, initiate a pull.

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

Index: linux-rt.git/kernel/sched/rt.c
===================================================================
--- linux-rt.git.orig/kernel/sched/rt.c
+++ linux-rt.git/kernel/sched/rt.c
@@ -997,6 +997,8 @@ inc_rt_prio(struct rt_rq *rt_rq, int pri
inc_rt_prio_smp(rt_rq, prio, prev_prio);
}

+static int pull_rt_task(struct rq *this_rq);
+
static void
dec_rt_prio(struct rt_rq *rt_rq, int prio)
{
@@ -1021,6 +1023,9 @@ dec_rt_prio(struct rt_rq *rt_rq, int pri
rt_rq->highest_prio.curr = MAX_RT_PRIO;

dec_rt_prio_smp(rt_rq, prio, prev_prio);
+
+ if (prev_prio < rt_rq->highest_prio.curr)
+ pull_rt_task(rq_of_rt_rq(rt_rq));
}

#else

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/