Logic for handling a failed SRT preemption due to an HRT task already being linked.

1 files changed, 9 insertions, 7 deletions

diff --git a/litmus/sched_edf_hsb.c b/litmus/sched_edf_hsb.c
index bcdb90bee2f4..7a1ceb4458ae 100644
--- a/litmus/sched_edf_hsb.c
+++ b/litmus/sched_edf_hsb.c
@@ -645,8 +645,9 @@ static noinline void link_server(cpu_entry_t *entry,
                         sched_trace_action(entry->linked, next_server->id);
                 }
 
-                if (next_server->type != S_SLACK) {
-                        BUG_ON(head_in_list(&server_slack(next_server)->list));
+                if (next_server->type != S_SLACK &&
+                    (head_in_list(&server_slack(next_server)->list))) {
+                        remove_slack(server_slack(next_server));
                 }
 
                 entry->linked_server = next_server;
@@ -1131,7 +1132,9 @@ static noinline void requeue(struct task_struct *task, rt_domain_t *domain)
         int was_added;
 
         BUG_ON(!is_realtime(task));
-        BUG_ON(head_in_list(&task_data(task)->candidate_list));
+        if (head_in_list(&task_data(task)->candidate_list)) {
+                list_del_init(&task_data(task)->candidate_list);
+        }
 
         check_slack_candidate(task);
 
@@ -2208,15 +2211,14 @@ static struct task_struct* edf_hsb_schedule(struct task_struct *prev)
                         entry->scheduled->rt_param.scheduled_on = NO_CPU;
         }
 
-        if (preempted && entry->linked && entry->scheduled &&
-            is_hrt(entry->linked) && !is_hrt(entry->scheduled))
-                check_for_global_preempt();
 
         entry->scheduled = entry->linked;
         entry->scheduled_server = entry->linked_server;
         sched_state_task_picked();
 
-
+        if (preempted && entry->linked && curr &&
+            is_hrt(entry->linked) && !is_hrt(curr))
+                check_for_global_preempt();
 
         if (entry->scheduled)
                 TRACE_TASK(entry->scheduled, "scheduled at %llu\n",