From: Steven Rostedt <srostedt@redhat.com>
This patch adds pushing of overloaded RT tasks from a runqueue that is
having tasks (most likely RT tasks) added to the run queue.
TODO: We don't cover the case of waking of new RT tasks (yet).
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
---
kernel/sched.c | 3 +++
kernel/sched_rt.c | 10 ++++++++++
2 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index a30147e..ebd114b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -22,6 +22,8 @@
* by Peter Williams
* 2007-05-06 Interactivity improvements to CFS by Mike Galbraith
* 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri
+ * 2007-10-22 RT overload balancing by Steven Rostedt
+ * (with thanks to Gregory Haskins)
*/
#include <linux/mm.h>
@@ -1641,6 +1643,7 @@ out_activate:
out_running:
p->state = TASK_RUNNING;
+ wakeup_balance_rt(rq, p);
out:
task_rq_unlock(rq, &flags);
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index a2f1057..a0b05ff 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -556,6 +556,15 @@ static void schedule_tail_balance_rt(struct rq *rq)
}
}
+
+static void wakeup_balance_rt(struct rq *rq, struct task_struct *p)
+{
+ if (unlikely(rt_task(p)) &&
+ !task_running(rq, p) &&
+ (p->prio >= rq->curr->prio))
+ push_rt_tasks(rq);
+}
+
/*
* Load-balancing iterator. Note: while the runqueue stays locked
* during the whole iteration, the current task might be
@@ -663,6 +672,7 @@ move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
#else /* CONFIG_SMP */
# define schedule_tail_balance_rt(rq) do { } while (0)
# define schedule_balance_rt(rq, prev) do { } while (0)
+# define wakeup_balance_rt(rq, p) do { } while (0)
#endif /* CONFIG_SMP */
static void task_tick_rt(struct rq *rq, struct task_struct *p)
--
