LITMUS^RT core: add generic handler for sporadic job arrivals

In particular, check if a job arrival is triggered from a
clock_nanosleep() call.

2 files changed, 23 insertions, 0 deletions

diff --git a/include/litmus/jobs.h b/include/litmus/jobs.h
index 1770e21b97c9..7033393148df 100644
--- a/include/litmus/jobs.h
+++ b/include/litmus/jobs.h
@@ -4,6 +4,8 @@
 void prepare_for_next_period(struct task_struct *t);
 void release_at(struct task_struct *t, lt_t start);
 
+void inferred_sporadic_job_release_at(struct task_struct *t, lt_t when);
+
 long default_wait_for_release_at(lt_t release_time);
 long complete_job(void);
 long complete_job_oneshot(void);
diff --git a/litmus/jobs.c b/litmus/jobs.c
index 250ee8dfd68b..1c700f9acd24 100644
--- a/litmus/jobs.c
+++ b/litmus/jobs.c
@@ -58,6 +58,27 @@ void release_at(struct task_struct *t, lt_t start)
         tsk_rt(t)->completed = 0;
 }
 
+void inferred_sporadic_job_release_at(struct task_struct *t, lt_t when)
+{
+        /* new sporadic release */
+        sched_trace_last_suspension_as_completion(t);
+        /* check if this task is resuming from a clock_nanosleep() call */
+        if (tsk_rt(t)->doing_abs_nanosleep &&
+            lt_after_eq(tsk_rt(t)->nanosleep_wakeup,
+                        get_release(t) + get_rt_period(t))) {
+                /* clock_nanosleep() is supposed to wake up the task
+                 * at a time that is a valid release time. Use that time
+                 * rather than guessing the intended release time from the
+                 * current time. */
+                TRACE_TASK(t, "nanosleep: backdating release "
+                        "to %llu instead of %llu\n",
+                        tsk_rt(t)->nanosleep_wakeup, when);
+                when = tsk_rt(t)->nanosleep_wakeup;
+        }
+        release_at(t, when);
+        sched_trace_task_release(t);
+}
+
 long default_wait_for_release_at(lt_t release_time)
 {
         struct task_struct *t = current;