EDF-WM: add parameter checking to wm_admit_task

2 files changed, 59 insertions, 2 deletions

diff --git a/include/litmus/rt_param.h b/include/litmus/rt_param.h
index f0b7b1c54134..65d2d7c7b783 100644
--- a/include/litmus/rt_param.h
+++ b/include/litmus/rt_param.h
@@ -40,6 +40,7 @@ typedef enum {
  * is called a 'slice'.
  */
 #define MAX_EDF_WM_SLICES NR_CPUS
+#define MIN_EDF_WM_SLICE_SIZE 1000000 /* 1 millisecond */
 
 struct edf_wm_slice {
         /* on which CPU is this slice allocated */
diff --git a/litmus/sched_edf_wm.c b/litmus/sched_edf_wm.c
index 135f618db6b3..4700c77a886a 100644
--- a/litmus/sched_edf_wm.c
+++ b/litmus/sched_edf_wm.c
@@ -400,9 +400,65 @@ static void wm_task_exit(struct task_struct * t)
         raw_spin_unlock_irqrestore(&dom->slock, flags);
 }
 
-static long wm_admit_task(struct task_struct* tsk)
+static long wm_check_params(struct task_struct *t)
 {
-        return task_cpu(tsk) == tsk->rt_param.task_params.cpu ? 0 : -EINVAL;
+        struct rt_param* p = tsk_rt(t);
+        struct edf_wm_params* wm = &p->task_params.semi_part.wm;
+        int i;
+        lt_t tmp;
+
+        if (!is_sliced_task(t))
+                /* regular task; nothing to check */
+                return 0;
+
+        /* (1) Either not sliced, or more than 1 slice. */
+        if (wm->count == 1 || wm->count > MAX_EDF_WM_SLICES)
+                return -EINVAL;
+
+        /* (2) The partition has to agree with the first slice. */
+        if (get_partition(t) != wm->slices[0].cpu)
+                return -EINVAL;
+
+        /* (3) The total budget must agree. */
+        for (i = 0, tmp = 0; i < wm->count; i++)
+                tmp += wm->slices[i].budget;
+        if (get_exec_cost(t) != tmp)
+                return -EINVAL;
+
+        /* (4) The release of each slice must not precede the previous
+         *     deadline. */
+        for (i = 0; i < wm->count - 1; i++)
+                if (wm->slices[i].deadline > wm->slices[i + 1].offset)
+                        return -EINVAL;
+
+        /* (5) The budget of each slice must fit within [offset, deadline] */
+        for (i = 0; i < wm->count; i++)
+                if (lt_before(wm->slices[i].deadline, wm->slices[i].offset) ||
+                    wm->slices[i].deadline - wm->slices[i].offset <
+                    wm->slices[i].budget)
+                        return -EINVAL;
+
+        /* (6) The budget of each slice must exceed the minimum budget size. */
+        for (i = 0; i < wm->count; i++)
+                if (wm->slices[i].budget < MIN_EDF_WM_SLICE_SIZE)
+                        return -EINVAL;
+
+        /* (7) The CPU of each slice must be different from the previous CPU. */
+        for (i = 0; i < wm->count - 1; i++)
+                if (wm->slices[i].cpu == wm->slices[i + 1].cpu)
+                        return -EINVAL;
+
+        /* (8) The CPU of each slice must be online. */
+        for (i = 0; i < wm->count; i++)
+                if (!cpu_online(wm->slices[i].cpu))
+                        return -EINVAL;
+
+        return 0;
+}
+
+static long wm_admit_task(struct task_struct* t)
+{
+        return task_cpu(t) == get_partition(t) ? wm_check_params(t) : -EINVAL;
 }
 
 /*      Plugin object   */