Plugin interface: add fork_task() callback

2 files changed, 11 insertions, 0 deletions

diff --git a/include/litmus/sched_plugin.h b/include/litmus/sched_plugin.h
index f36bb3875f58..0c2aabad40c9 100644
--- a/include/litmus/sched_plugin.h
+++ b/include/litmus/sched_plugin.h
@@ -72,6 +72,9 @@ typedef long (*complete_job_t) (void);
 
 typedef long (*admit_task_t)(struct task_struct* tsk);
 
+/* return false to indicate that the plugin does not support forking */
+typedef bool (*fork_task_t)(struct task_struct* tsk);
+
 typedef long (*wait_for_release_at_t)(lt_t release_time);
 
 /* Informs the plugin when a synchronous release takes place. */
@@ -108,6 +111,7 @@ struct sched_plugin {
 
         /*      task state changes      */
         admit_task_t            admit_task;
+        fork_task_t                     fork_task;
 
         task_new_t              task_new;
         task_wake_up_t          task_wake_up;
diff --git a/litmus/sched_plugin.c b/litmus/sched_plugin.c
index 7b1eba0de75c..6ab5b85082c9 100644
--- a/litmus/sched_plugin.c
+++ b/litmus/sched_plugin.c
@@ -77,6 +77,12 @@ static long litmus_dummy_admit_task(struct task_struct* tsk)
         return -EINVAL;
 }
 
+static bool litmus_dummy_fork_task(struct task_struct* tsk)
+{
+        /* Default behavior: return false to demote to non-real-time task */
+        return false;
+}
+
 static void litmus_dummy_task_new(struct task_struct *t, int on_rq, int running)
 {
 }
@@ -193,6 +199,7 @@ int register_sched_plugin(struct sched_plugin* plugin)
         CHECK(allocate_lock);
 #endif
         CHECK(admit_task);
+        CHECK(fork_task);
         CHECK(synchronous_release_at);
 
         if (!plugin->wait_for_release_at)