adaptive: fix weight change metric

It does not depend on absolute error, but on relative change.

1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/sched_adaptive.c b/kernel/sched_adaptive.c
index 8ccb7a006e..54d707b880 100644
--- a/kernel/sched_adaptive.c
+++ b/kernel/sched_adaptive.c
@@ -141,6 +141,7 @@ static void set_service_level(struct task_struct* t, unsigned int level)
 
 void adaptive_optimize(void)
 {
+        TRACE("running adaptive optimizer\n");
         last_optimizer_run = jiffies;
 }
 
@@ -394,7 +395,7 @@ static reschedule_check_t adaptive_scheduler_tick(void)
 static noinline void job_completion(struct task_struct *t)
 {
         long delta;
-        fp_t actual_weight;
+        fp_t actual_weight, old_estimate;
         BUG_ON(!t);
 
         sched_trace_job_completion(t);
@@ -403,9 +404,12 @@ static noinline void job_completion(struct task_struct *t)
 
         actual_weight = _frac(t->rt_param.times.exec_time, 
                               t->rt_param.basic_params.period);
+        old_estimate = get_estimated_weight(t);
         update_estimate(&t->rt_param.predictor_state, actual_weight, 
                         fc_a, fc_b, fc_c);
-        if (_gt(_abs(t->rt_param.predictor_state.error), task_error_threshold))
+        if (_gt(_div(_abs(get_estimated_weight(t) - old_estimate),
+                     get_estimate_weight(t)), 
+                task_error_threshold))
                 adaptive_optimize();
 
         TRACE_TASK(t, "job %d completes, delta WCET = %d\n",