define BACKOFF_MAX to 16384 for spinning

src/drivers/driver_common/driver_common.c

@@ -29,8 +29,8 @@
 #include <core/debug.h>
 
 
-#define BACKOFF_MAX 8192  /* TODO : calibrate MAX & MIN */
-#define BACKOFF_MIN 4
+#define BACKOFF_MAX 16384  /* TODO : use parameter to define them */
+#define BACKOFF_MIN 32
 
 void _starpu_driver_start_job(struct _starpu_worker *args, struct _starpu_job *j, struct timespec *codelet_start, int rank, int profiling)
 {