LITMUS: Add the PFAIR plugin.RTSS08

This adds the PFAIR plugin. The implementation is based on an earlier version
developed by John Calandrino.

Features:

        - supports aligned and staggered quanta
        - supports early releasing
        - uses mergable heaps to limit overheads

This version still has a couple of limitations:

        - no support for sporadic; all tasks are assumed to be periodic
        - tasks are limited to a maximum period  of 1000 quanta
        - overload (especially in the tick) is not handled gracefully

1 files changed, 8 insertions, 6 deletions

diff --git a/include/litmus/rt_param.h b/include/litmus/rt_param.h
index a7dd67a81a..7bb568432e 100644
--- a/include/litmus/rt_param.h
+++ b/include/litmus/rt_param.h
@@ -64,6 +64,8 @@ struct rt_job {
 };
 
 
+struct pfair_param;
+
 /*      RT task parameters for scheduling extensions
  *      These parameters are inherited during clone and therefore must
  *      be explicitly set up before the task set is launched.
@@ -108,15 +110,12 @@ struct rt_param {
          * is currently scheduled. It is the responsibility of the
          * plugin to avoid race conditions.
          *
-         * Used by GSN-EDF.
+         * This used by GSN-EDF and PFAIR.
          */
         volatile int            scheduled_on;
 
-        /* Is the stack of the task currently in use? Currently, this
-         * is the responsibility of the plugin to update this field.
-         * Maybe become part of the LITMUS core some day.
-         * 
-         * Used by GSN-EDF.
+        /* Is the stack of the task currently in use? This is updated by
+         * the LITMUS core.
          *
          * Be careful to avoid deadlocks!
          */
@@ -130,6 +129,9 @@ struct rt_param {
          */
         volatile int            linked_on;
 
+        /* PFAIR/PD^2 state. Allocated on demand. */
+        struct pfair_param*     pfair;
+
         /* Fields saved before BE->RT transition.
          */
         int old_policy;