Add GPU affinity tracking.

Adds GPU affinity tracking/prediction routines. Tracking
uses a process-chart method whereby observations over two
standard deviations below or above the average are discarded.

1 files changed, 58 insertions, 0 deletions

diff --git a/include/litmus/gpu_affinity.h b/include/litmus/gpu_affinity.h
new file mode 100644
index 000000000000..de5d1a5ab9e9
--- /dev/null
+++ b/include/litmus/gpu_affinity.h
@@ -0,0 +1,58 @@
+#ifndef LITMUS_GPU_AFFINITY_H
+#define LITMUS_GPU_AFFINITY_H
+
+#include <litmus/rt_param.h>
+#include <litmus/sched_plugin.h>
+#include <litmus/litmus.h>
+
+void update_gpu_estimate(struct task_struct* t, lt_t observed);
+gpu_migration_dist_t gpu_migration_distance(int a, int b);
+
+static inline void reset_gpu_tracker(struct task_struct* t)
+{
+        t->rt_param.accum_gpu_time = 0;
+        t->rt_param.gpu_time_stamp = 0;
+}
+
+static inline void start_gpu_tracker(struct task_struct* t)
+{
+        lt_t now = litmus_clock();
+        if (likely(!t->rt_param.gpu_time_stamp))
+                t->rt_param.gpu_time_stamp = now;
+}
+
+static inline void stop_gpu_tracker(struct task_struct* t)
+{
+        lt_t now = litmus_clock();
+        if (likely(t->rt_param.gpu_time_stamp)) {
+                t->rt_param.accum_gpu_time += (now - t->rt_param.gpu_time_stamp);
+                t->rt_param.gpu_time_stamp = 0;
+        }
+}
+
+static inline lt_t get_gpu_time(struct task_struct* t)
+{
+        lt_t accum = t->rt_param.accum_gpu_time;
+        if (t->rt_param.gpu_time_stamp != 0)
+                accum += (litmus_clock() - t->rt_param.gpu_time_stamp);
+        return accum;
+}
+
+static inline lt_t get_gpu_estimate(struct task_struct* t,
+                                gpu_migration_dist_t dist)
+{
+        int i;
+        lt_t val;
+
+        if(dist == MIG_NONE)
+                dist = MIG_LOCAL;
+
+        val = t->rt_param.gpu_migration_est[dist].avg;
+        for(i = dist-1; i >= 0; --i)
+                if(t->rt_param.gpu_migration_est[i].avg > val)
+                        val = t->rt_param.gpu_migration_est[i].avg;
+
+        return ((val > 0) ? val : dist+1);
+}
+
+#endif