Integrate LITMUS^RT scheduling class with sched_setscheduler

1 files changed, 32 insertions, 2 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 426f4e776188..1fe02e0e801c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -91,6 +91,7 @@
 #include <litmus/ceiling.h>
 #include <litmus/trace.h>
 #include <litmus/sched_trace.h>
+#include <litmus/sched_plugin.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/sched.h>
@@ -3380,7 +3381,9 @@ static void __setscheduler(struct rq *rq, struct task_struct *p,
         else
                 p->prio = normal_prio(p);
 
-        if (dl_prio(p->prio))
+        if (p->policy == SCHED_LITMUS)
+                p->sched_class = &litmus_sched_class;
+        else if (dl_prio(p->prio))
                 p->sched_class = &dl_sched_class;
         else if (rt_prio(p->prio))
                 p->sched_class = &rt_sched_class;
@@ -3483,6 +3486,7 @@ static int __sched_setscheduler(struct task_struct *p,
         const struct sched_class *prev_class;
         struct rq *rq;
         int reset_on_fork;
+        int litmus_task = 0;
 
         /* may grab non-irq protected spin_locks */
         BUG_ON(in_interrupt());
@@ -3497,7 +3501,7 @@ recheck:
                 if (policy != SCHED_DEADLINE &&
                                 policy != SCHED_FIFO && policy != SCHED_RR &&
                                 policy != SCHED_NORMAL && policy != SCHED_BATCH &&
-                                policy != SCHED_IDLE)
+                                policy != SCHED_IDLE && policy != SCHED_LITMUS)
                         return -EINVAL;
         }
 
@@ -3515,6 +3519,8 @@ recheck:
         if ((dl_policy(policy) && !__checkparam_dl(attr)) ||
             (rt_policy(policy) != (attr->sched_priority != 0)))
                 return -EINVAL;
+        if (policy == SCHED_LITMUS && policy == p->policy)
+                return -EINVAL;
 
         /*
          * Allow unprivileged RT tasks to decrease priority:
@@ -3573,6 +3579,12 @@ 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:
@@ -3656,6 +3668,11 @@ change:
                 return -EBUSY;
         }
 
+        if (p->policy == SCHED_LITMUS) {
+                litmus_exit_task(p);
+                litmus_task = 1;
+        }
+
         p->sched_reset_on_fork = reset_on_fork;
         oldprio = p->prio;
 
@@ -3683,6 +3700,16 @@ change:
         prev_class = p->sched_class;
         __setscheduler(rq, p, attr, true);
 
+        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, queued, running);
+        }
+
         if (running)
                 p->sched_class->set_curr_task(rq);
         if (queued) {
@@ -3698,6 +3725,9 @@ change:
 
         rt_mutex_adjust_pi(p);
 
+        if (litmus_task)
+                litmus_dealloc(p);
+
         return 0;
 }