Integrate LITMUS^RT scheduling class with sched_setscheduler

1 files changed, 27 insertions, 2 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 90cc4b53cc5f..8debd642a22c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -89,6 +89,8 @@
 #include <litmus/litmus.h>
 #include <litmus/trace.h>
 #include <litmus/sched_trace.h>
+#include <litmus/sched_plugin.h>
+
 void litmus_tick(struct rq*, struct task_struct*);
 
 #define CREATE_TRACE_POINTS
@@ -3900,7 +3902,9 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
         p->normal_prio = normal_prio(p);
         /* we are holding p->pi_lock already */
         p->prio = rt_mutex_getprio(p);
-        if (rt_prio(p->prio))
+        if (p->policy == SCHED_LITMUS)
+                p->sched_class = &litmus_sched_class;
+        else if (rt_prio(p->prio))
                 p->sched_class = &rt_sched_class;
         else
                 p->sched_class = &fair_sched_class;
@@ -3945,7 +3949,7 @@ recheck:
 
                 if (policy != SCHED_FIFO && policy != SCHED_RR &&
                                 policy != SCHED_NORMAL && policy != SCHED_BATCH &&
-                                policy != SCHED_IDLE)
+                                policy != SCHED_IDLE && policy != SCHED_LITMUS)
                         return -EINVAL;
         }
 
@@ -3960,6 +3964,8 @@ recheck:
                 return -EINVAL;
         if (rt_policy(policy) != (param->sched_priority != 0))
                 return -EINVAL;
+        if (policy == SCHED_LITMUS && policy == p->policy)
+                return -EINVAL;
 
         /*
          * Allow unprivileged RT tasks to decrease priority:
@@ -4003,6 +4009,12 @@ recheck:
                         return retval;
         }
 
+        if (policy == SCHED_LITMUS) {
+                retval = litmus_admit_task(p);
+                if (retval)
+                        return retval;
+        }
+
         /*
          * make sure no PI-waiters arrive (or leave) while we are
          * changing the priority of the task:
@@ -4059,10 +4071,23 @@ recheck:
 
         p->sched_reset_on_fork = reset_on_fork;
 
+        if (p->policy == SCHED_LITMUS)
+                litmus_exit_task(p);
+
         oldprio = p->prio;
         prev_class = p->sched_class;
         __setscheduler(rq, p, policy, param->sched_priority);
 
+        if (policy == SCHED_LITMUS) {
+#ifdef CONFIG_SMP
+                p->rt_param.stack_in_use = running ? rq->cpu : NO_CPU;
+#else
+                p->rt_param.stack_in_use = running ? 0 : NO_CPU;
+#endif
+                p->rt_param.present = running;
+                litmus->task_new(p, on_rq, running);
+        }
+
         if (running)
                 p->sched_class->set_curr_task(rq);
         if (on_rq)