permit to take priorities into account in theoretical bound computation

doc/starpu.texi

@@ -1139,6 +1139,11 @@ on processing units. It however still properly takes into account the varying
 performances of kernels and processing units, which is quite more accurate than
 just comparing StarPU performances with the fastest of the kernels being used.
 
+The @code{prio} parameter tells StarPU whether to simulate taking into account
+the priorities as the StarPU scheduler would, i.e. schedule prioritized
+tasks before less prioritized tasks, to check to which extend this results
+to a less optimal solution. This increases even more computation time.
+
 Note that all this however doesn't take into account data transfer, which is
 assumed to be completely overlapped.
 

examples/lu/lu_example.c

@@ -33,6 +33,7 @@ static unsigned no_stride = 0;
 static unsigned profile = 0;
 static unsigned bound = 0;
 static unsigned bounddeps = 0;
+static unsigned boundprio = 0;
 
 TYPE *A, *A_saved;
 
@@ -76,6 +77,11 @@ static void parse_args(int argc, char **argv)
 			bound = 1;
 			bounddeps = 1;
 		}
+		if (strcmp(argv[i], "-bounddepsprio") == 0) {
+			bound = 1;
+			bounddeps = 1;
+			boundprio = 1;
+		}
 	}
 }
 
@@ -272,7 +278,7 @@ int main(int argc, char **argv)
 	display_matrix(A, size, size, "A");
 
 	if (bound)
-		starpu_bound_start(bounddeps);
+		starpu_bound_start(bounddeps, boundprio);
 
 	if (profile)
 		starpu_profiling_status_set(STARPU_PROFILING_ENABLE);

include/starpu_bound.h

@@ -24,7 +24,7 @@
 
 /* Start recording tasks (resets stats).  `deps' tells whether dependencies
  * should be recorded too (this is quite expensive).  */
-void starpu_bound_start(int deps);
+void starpu_bound_start(int deps, int prio);
 /* Stop recording tasks */
 void starpu_bound_stop(void);
 

src/profiling/bound.c

@@ -109,10 +109,11 @@ static struct bound_task *tasks;
 static struct bound_tag_dep *tag_deps;
 static int recording;
 static int recorddeps;
+static int recordprio;
 
 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
 
-void starpu_bound_start(int deps)
+void starpu_bound_start(int deps, int prio)
 {
 	struct bound_task_pool *tp;
 	struct bound_task *t;
@@ -132,6 +133,7 @@ void starpu_bound_start(int deps)
 
 	recording = 1;
 	recorddeps = deps;
+	recordprio = prio;
 
 	PTHREAD_MUTEX_UNLOCK(&mutex);
 
@@ -385,23 +387,112 @@ void starpu_bound_print_lp(FILE *output)
 		for (td = tag_deps; td; td = td->next)
 			fprintf(output, "tag%lu >= tag%lu;\n", (unsigned long) td->tag, (unsigned long) td->dep_tag);
 
+/* TODO: factorize ancestor calls */
 		fprintf(output, "\n/* For each task pair and each worker, if both tasks are executed by the same worker,\n");
 		fprintf(output, "   one is started after the other's completion */\n");
-		for (t = tasks; t; t = t->next)
+		for (t = tasks; t; t = t->next) {
 			for (t2 = t->next; t2; t2 = t2->next)
 			{
-				if (!ancestor(t, t2) && !ancestor(t2, t))
-				    for (w = 0; w < nw; w++) {
-					fprintf(output, "s%u - c%u >= -3e5 + 1e5 t%uw%u + 1e5 t%uw%u + 1e5 t%uafter%u;\n",
-							t->id, t2->id, t->id, w, t2->id, w, t->id, t2->id);
-					fprintf(output, "s%u - c%u >= -2e5 + 1e5 t%uw%u + 1e5 t%uw%u - 1e5 t%uafter%u;\n",
-							t2->id, t->id, t->id, w, t2->id, w, t->id, t2->id);
+				if (!ancestor(t, t2) && !ancestor(t2, t)) {
+					for (w = 0; w < nw; w++) {
+						fprintf(output, "s%u - c%u >= -3e5 + 1e5 t%uw%u + 1e5 t%uw%u + 1e5 t%uafter%u;\n",
+								t->id, t2->id, t->id, w, t2->id, w, t->id, t2->id);
+						fprintf(output, "s%u - c%u >= -2e5 + 1e5 t%uw%u + 1e5 t%uw%u - 1e5 t%uafter%u;\n",
+								t2->id, t->id, t->id, w, t2->id, w, t->id, t2->id);
+					}
 				}
 			}
+		}
+
+#if 0
+/* Doesn't help at all to actually express what "after" means */
 		for (t = tasks; t; t = t->next)
 			for (t2 = t->next; t2; t2 = t2->next)
 				if (!ancestor(t, t2) && !ancestor(t2, t))
-				fprintf(output, "bin t%uafter%u;\n", t->id, t2->id);
+				{
+					fprintf(output, "s%u - s%u >= -1e5 + 1e5 t%uafter%u;\n", t->id, t2->id, t->id, t2->id);
+					fprintf(output, "s%u - s%u >= -1e5 t%uafter%u;\n", t2->id, t->id, t->id, t2->id);
+				}
+#endif
+
+		if (recordprio) {
+			fprintf(output, "\n/* For StarPU, a priority means given schedulable tasks it will consider the\n");
+			fprintf(output, " * more prioritized first */\n");
+			for (t = tasks; t; t = t->next) {
+				for (t2 = t->next; t2; t2 = t2->next)
+				{
+					if (!ancestor(t, t2) && !ancestor(t2, t)
+					     && t->priority != t2->priority) {
+						if (t->priority > t2->priority) {
+							/* Either t2 is scheduled before t, but then it
+							   needs to be scheduled before some t dep finishes */
+
+							/* One of the t deps to give the maximum start time for t2 */
+							if (t->depsn > 1) {
+								for (i = 0; i < t->depsn; i++)
+									fprintf(output, " + t%ut%ud%u", t2->id, t->id, i);
+								fprintf(output, " = 1;\n");
+							}
+
+							for (i = 0; i < t->depsn; i++) {
+								fprintf(output, "c%u - s%u >= ", t->deps[i]->id, t2->id);
+								if (t->depsn > 1)
+									/* Only checks this when it's this dependency that is chosen */
+									fprintf(output, "-2e5 + 1e5 t%ut%ud%u", t2->id, t->id, i);
+								else
+									fprintf(output, "-1e5");
+								/* Only check this if t is after t2 */
+								fprintf(output, " + 1e5 t%uafter%u", t->id, t2->id);
+								fprintf(output, ";\n");
+							}
+
+							/* Or t2 is scheduled after t is.  */
+							fprintf(output, "s%u - s%u >= -1e5 t%uafter%u;\n", t2->id, t->id, t->id, t2->id);
+						} else {
+							/* Either t is scheduled before t2, but then it
+							   needs to be scheduled before some t2 dep finishes */
+
+							/* One of the t2 deps to give the maximum start time for t */
+							if (t2->depsn > 1) {
+								for (i = 0; i < t2->depsn; i++)
+									fprintf(output, " + t%ut%ud%u", t->id, t2->id, i);
+								fprintf(output, " = 1;\n");
+							}
+
+							for (i = 0; i < t2->depsn; i++) {
+								fprintf(output, "c%u - s%u >= ", t2->deps[i]->id, t->id);
+								if (t2->depsn > 1)
+									/* Only checks this when it's this dependency that is chosen */
+									fprintf(output, "-1e5 + 1e5 t%ut%ud%u", t->id, t2->id, i);
+								/* Only check this if t2 is after t */
+								fprintf(output, " - 1e5 t%uafter%u;\n", t->id, t2->id);
+							}
+
+							/* Or t is scheduled after t2 is.  */
+							fprintf(output, "s%u - s%u >= -1e5 + 1e5 t%uafter%u;\n", t->id, t2->id, t->id, t2->id);
+						}
+					}
+				}
+			}
+		}
+
+
+		for (t = tasks; t; t = t->next)
+			for (t2 = t->next; t2; t2 = t2->next)
+				if (!ancestor(t, t2) && !ancestor(t2, t)) {
+					fprintf(output, "bin t%uafter%u;\n", t->id, t2->id);
+					if (recordprio && t->priority != t2->priority) {
+						if (t->priority > t2->priority) {
+							if (t->depsn > 1)
+								for (i = 0; i < t->depsn; i++)
+									fprintf(output, "bin t%ut%ud%u;\n", t2->id, t->id, i);
+						} else {
+							if (t2->depsn > 1)
+								for (i = 0; i < t2->depsn; i++)
+									fprintf(output, "bin t%ut%ud%u;\n", t->id, t2->id, i);
+						}
+					}
+				}
 
 		for (t = tasks; t; t = t->next)
 			for (w = 0; w < nw; w++)