1 files changed, 58 insertions, 0 deletions

diff --git a/litmus/fifo_common.c b/litmus/fifo_common.c
new file mode 100644
index 000000000000..84ae98e42ae4
--- /dev/null
+++ b/litmus/fifo_common.c
@@ -0,0 +1,58 @@
+/*
+ * kernel/edf_common.c
+ *
+ * Common functions for EDF based scheduler.
+ */
+
+#include <linux/percpu.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+
+#include <litmus/litmus.h>
+#include <litmus/sched_plugin.h>
+#include <litmus/sched_trace.h>
+
+#include <litmus/fifo_common.h>
+
+int fifo_higher_prio(struct task_struct* first,
+                    struct task_struct* second)
+{
+        /* There is no point in comparing a task to itself. */
+        if (first && first == second) {
+                TRACE_TASK(first,
+                           "WARNING: pointless fifo priority comparison.\n");
+                BUG_ON(1);
+                return 0;
+        }
+
+        if (!first || !second)
+                return first && !second;
+
+        /* Tiebreak by PID */
+        return  (get_release(first) == get_release(second) &&
+                 first->pid > second->pid) ||
+                (get_release(first) < get_release(second));
+
+
+}
+
+int fifo_ready_order(struct bheap_node* a, struct bheap_node* b)
+{
+        return fifo_higher_prio(bheap2task(a), bheap2task(b));
+}
+
+void fifo_domain_init(rt_domain_t* rt, check_resched_needed_t resched,
+                      release_jobs_t release)
+{
+        rt_domain_init(rt,  fifo_ready_order, resched, release);
+}
+
+int fifo_preemption_needed(rt_domain_t* rt, struct task_struct *t)
+{
+        if (!__jobs_pending(rt))
+                return 0;
+        if (!t)
+                return 1;
+
+        return !is_realtime(t) || fifo_higher_prio(__next_ready(rt), t);
+}