P-FP: be paranoid in the preemption case

Crash and burn if an expected preemption didn't happen. This is useful
to flag any bugs in the queue management code...

1 files changed, 5 insertions, 0 deletions

diff --git a/litmus/sched_pfp.c b/litmus/sched_pfp.c
index f69b6f61dfeb..2165e1c79df5 100644
--- a/litmus/sched_pfp.c
+++ b/litmus/sched_pfp.c
@@ -225,6 +225,11 @@ static struct task_struct* pfp_schedule(struct task_struct * prev)
                 if (pfp->scheduled && !blocks  && !migrate)
                         requeue(pfp->scheduled, pfp);
                 next = fp_prio_take(&pfp->ready_queue);
+                /* If preempt is set, we should not see the same task again. */
+                BUG_ON(preempt && next == prev);
+                /* Similarly, if preempt is set, then next may not be NULL,
+                 * unless it's a migration. */
+                BUG_ON(preempt && !migrate && next == NULL);
         } else
                 /* Only override Linux scheduler if we have a real-time task
                  * scheduled that needs to continue.