checkpoint for aux_tasks. can still deadlock

1 files changed, 50 insertions, 61 deletions

diff --git a/litmus/litmus.c b/litmus/litmus.c
index 83e8ef3f42af..1b4182ac3337 100644
--- a/litmus/litmus.c
+++ b/litmus/litmus.c
@@ -25,6 +25,10 @@
 #include <litmus/nvidia_info.h>
 #endif
 
+#ifdef CONFIG_LITMUS_LOCKING
+#include <litmus/aux_tasks.h>
+#endif
+
 /* Number of RT tasks that exist in the system */
 atomic_t rt_task_count          = ATOMIC_INIT(0);
 static DEFINE_RAW_SPINLOCK(task_transition_lock);
@@ -327,60 +331,6 @@ asmlinkage long sys_null_call(cycles_t __user *ts)
         return ret;
 }
 
-
-long __litmus_admit_task(struct task_struct* tsk);
-
-asmlinkage long sys_slave_non_rt_threads(void)
-{
-        long retval = 0;
-        struct task_struct *leader = current->group_leader;
-        struct task_struct *t;
-        struct task_struct *hp = NULL;
-
-        read_lock_irq(&tasklist_lock);
-
-        t = leader;
-        do {
-                TRACE_CUR("threads in %s/%d: %s/%d:\n", leader->comm, leader->pid, t->comm, t->pid);
-
-                if (tsk_rt(t)->heap_node == NULL) {
-                        retval = __litmus_admit_task(t);
-
-                        if (retval != 0) break;
-
-                        /* hasn't been admitted into rt. make it a slave. */
-                        tsk_rt(t)->slave = 1;
-                }
-                else {
-                        tsk_rt(t)->has_slaves = 1;
-
-                        if (is_realtime(t) && litmus->compare(t, hp)) {
-                                hp = t;
-                        }
-                }
-
-                t = next_thread(t);
-        } while(t != leader);
-
-        if (hp) {
-                TRACE_CUR("found hp in group: %s/%d\n", hp->comm, hp->pid);
-
-                /* set up inheritance */
-                leader->hp_group = hp;
-
-                t = leader;
-                do {
-                        if (tsk_rt(t)->slave) {
-                                litmus->increase_prio(t);
-                        }
-                } while(t != leader);
-        }
-
-        read_unlock_irq(&tasklist_lock);
-
-        return 0;
-}
-
 #if defined(CONFIG_LITMUS_NVIDIA) && defined(CONFIG_LITMUS_AFFINITY_LOCKING)
 void init_gpu_affinity_state(struct task_struct* p)
 {
@@ -412,11 +362,13 @@ static void reinit_litmus_state(struct task_struct* p, int restore)
 {
         struct rt_task  user_config = {};
         void*  ctrl_page     = NULL;
-
+        
 #ifdef CONFIG_LITMUS_NESTED_LOCKING
         binheap_order_t prio_order = NULL;
 #endif
 
+        TRACE_TASK(p, "reinit_litmus_state: restore = %d\n", restore);
+        
         if (restore) {
                 /* Safe user-space provided configuration data.
                  * and allocated page. */
@@ -428,10 +380,12 @@ static void reinit_litmus_state(struct task_struct* p, int restore)
         prio_order = p->rt_param.hp_blocked_tasks.compare;
 #endif
 
+#ifdef CONFIG_LITMUS_LOCKING
         /* We probably should not be inheriting any task's priority
          * at this point in time.
          */
         WARN_ON(p->rt_param.inh_task);
+#endif
 
 #ifdef CONFIG_LITMUS_NESTED_LOCKING
         WARN_ON(p->rt_param.blocked_lock);
@@ -459,6 +413,13 @@ static void reinit_litmus_state(struct task_struct* p, int restore)
         /* Cleanup everything else. */
         memset(&p->rt_param, 0, sizeof(p->rt_param));
 
+#ifdef CONFIG_LITMUS_LOCKING
+        /* also clear out the aux_data. the !restore case is only called on
+         * fork (initial thread creation). */
+        if (!restore)
+                memset(&p->aux_data, 0, sizeof(p->aux_data));
+#endif
+        
         /* Restore preserved fields. */
         if (restore) {
                 p->rt_param.task_params = user_config;
@@ -475,7 +436,12 @@ static void reinit_litmus_state(struct task_struct* p, int restore)
 #endif
 }
 
+
+#ifdef CONFIG_LITMUS_LOCKING
+long __litmus_admit_task(struct task_struct* tsk, int clear_aux)
+#else
 long __litmus_admit_task(struct task_struct* tsk)
+#endif
 {
         long retval = 0;
         unsigned long flags;
@@ -520,6 +486,14 @@ long __litmus_admit_task(struct task_struct* tsk)
         atomic_set(&tsk_rt(tsk)->klitirqd_sem_stat, NOT_HELD);
 #endif
 
+#ifdef CONFIG_LITMUS_LOCKING
+        /* turns out our aux thread isn't really an aux thread. */
+        if (clear_aux && tsk_rt(tsk)->is_aux_task) {
+                exit_aux_task(tsk);
+                tsk_rt(tsk)->has_aux_tasks = 1;
+        }
+#endif
+        
         retval = litmus->admit_task(tsk);
 
         if (!retval) {
@@ -537,8 +511,7 @@ out_unlock:
 long litmus_admit_task(struct task_struct* tsk)
 {
         long retval = 0;
-        unsigned long flags;
-
+        
         BUG_ON(is_realtime(tsk));
 
         if (get_rt_relative_deadline(tsk) == 0 ||
@@ -560,8 +533,12 @@ long litmus_admit_task(struct task_struct* tsk)
                 goto out;
         }
 
+#ifdef CONFIG_LITMUS_LOCKING
+        retval = __litmus_admit_task(tsk, (tsk_rt(tsk)->task_params.period != MAGIC_AUX_TASK_PERIOD));
+#else
         retval = __litmus_admit_task(tsk);
-
+#endif
+        
 out:
         return retval;
 }
@@ -574,7 +551,7 @@ void litmus_exit_task(struct task_struct* tsk)
                 litmus->task_exit(tsk);
 
                 BUG_ON(bheap_node_in_heap(tsk_rt(tsk)->heap_node));
-                bheap_node_free(tsk_rt(tsk)->heap_node);
+                bheap_node_free(tsk_rt(tsk)->heap_node);
                 release_heap_free(tsk_rt(tsk)->rel_heap);
 
                 atomic_dec(&rt_task_count);
@@ -647,14 +624,22 @@ out:
  */
 void litmus_fork(struct task_struct* p)
 {
+        reinit_litmus_state(p, 0);
+        
         if (is_realtime(p)) {
+                TRACE_TASK(p, "fork, is real-time\n");
                 /* clean out any litmus related state, don't preserve anything */
-                reinit_litmus_state(p, 0);
+                //reinit_litmus_state(p, 0);
                 /* Don't let the child be a real-time task.  */
                 p->sched_reset_on_fork = 1;
-        } else
+        } else {
                 /* non-rt tasks might have ctrl_page set */
                 tsk_rt(p)->ctrl_page = NULL;
+                
+                /* still don't inherit any parental parameters */
+                //memset(&p->rt_param, 0, sizeof(p->rt_param));
+                //memset(&p->aux_data, 0, sizeof(p->aux_data));
+        }
 
         /* od tables are never inherited across a fork */
         p->od_table = NULL;
@@ -751,6 +736,10 @@ static int __init _init_litmus(void)
         init_topology();
 #endif
 
+#ifdef CONFIG_LITMUS_NVIDIA
+        //init_nvidia_info();
+#endif
+
         return 0;
 }