Make use of kernel-provided FP macros

Use the kernel's notion of fixed priorities.
Also, add some clarifying comments to the
task setup wrappers.

2 files changed, 15 insertions, 7 deletions

diff --git a/bin/rtspin.c b/bin/rtspin.c
index 87c178a..f0a477d 100644
--- a/bin/rtspin.c
+++ b/bin/rtspin.c
@@ -169,7 +169,7 @@ int main(int argc, char** argv)
         lt_t wcet;
         lt_t period;
         double wcet_ms, period_ms;
-        unsigned int priority = LITMUS_MIN_PRIORITY;
+        unsigned int priority = LITMUS_LOWEST_PRIORITY;
         int migrate = 0;
         int cpu = 0;
         int opt;
@@ -197,7 +197,7 @@ int main(int argc, char** argv)
                         break;
                 case 'q':
                         priority = atoi(optarg);
-                        if (priority == 0 || priority > LITMUS_MAX_PRIORITY)
+                        if (!litmus_is_valid_fixed_prio(priority))
                                 usage("Invalid priority.");
                         break;
                 case 'c':
diff --git a/include/litmus.h b/include/litmus.h
index 232dcf5..3fa2a57 100644
--- a/include/litmus.h
+++ b/include/litmus.h
@@ -29,26 +29,34 @@ int get_rt_task_param(pid_t pid, struct rt_task* param);
 
 /* setup helper */
 
-/* times are given in ms */
+/* Times are given in ms. The 'priority' parameter
+ * is only relevant under fixed-priority scheduling (and
+ * ignored by other plugins). The task_class_t parameter
+ * is ignored by most plugins.
+ */
 int sporadic_task(
                 lt_t e, lt_t p, lt_t phase,
                 int partition, unsigned int priority,
                 task_class_t cls,
                 budget_policy_t budget_policy, int set_cpu_set);
 
-/* times are given in ns */
+/* Times are given in ns. The 'priority' parameter
+ * is only relevant under fixed-priority scheduling (and
+ * ignored by other plugins). The task_class_t parameter
+ * is ignored by most plugins.
+ */
 int sporadic_task_ns(
                 lt_t e, lt_t p, lt_t phase,
                 int cpu, unsigned int priority,
                 task_class_t cls,
                 budget_policy_t budget_policy, int set_cpu_set);
 
-/* budget enforcement off by default in these macros */
+/* Convenience macros. Budget enforcement off by default in these macros. */
 #define sporadic_global(e, p) \
-        sporadic_task(e, p, 0, 0, LITMUS_MAX_PRIORITY-1, \
+        sporadic_task(e, p, 0, 0, LITMUS_LOWEST_PRIORITY, \
                 RT_CLASS_SOFT, NO_ENFORCEMENT, 0)
 #define sporadic_partitioned(e, p, cpu) \
-        sporadic_task(e, p, 0, cpu, LITMUS_MAX_PRIORITY-1, \
+        sporadic_task(e, p, 0, cpu, LITMUS_LOWEST_PRIORITY, \
                 RT_CLASS_SOFT, NO_ENFORCEMENT, 1)
 
 /* file descriptor attached shared objects support */