improve locality of variables by using a structure instead of separate arrays

src/core/simgrid.c

@@ -45,12 +45,13 @@ static int simgrid_started;
 starpu_pthread_queue_t _starpu_simgrid_transfer_queue[STARPU_MAXNODES];
 
 starpu_pthread_queue_t _starpu_simgrid_task_queue[STARPU_NMAXWORKERS];
-static struct task *first_task[STARPU_NMAXWORKERS];
-static struct task *last_task[STARPU_NMAXWORKERS];
-static msg_sem_t worker_sem[STARPU_NMAXWORKERS];
-static msg_process_t worker_runner[STARPU_NMAXWORKERS];
-static int task_execute(int argc STARPU_ATTRIBUTE_UNUSED, char *argv[] STARPU_ATTRIBUTE_UNUSED);
 static int runners_running;
+static struct worker_runner {
+	struct task *first_task, *last_task;
+	msg_sem_t sem;
+	msg_process_t runner;
+} worker_runner[STARPU_NMAXWORKERS];
+static int task_execute(int argc STARPU_ATTRIBUTE_UNUSED, char *argv[] STARPU_ATTRIBUTE_UNUSED);
 
 /* In case the MPI application didn't use smpicc to build the file containing
  * main(), try to cope by calling starpu_main */
@@ -326,9 +327,9 @@ void _starpu_simgrid_init(void)
 		char s[32];
 		snprintf(s, sizeof(s), "worker %u runner", i);
 		void **tsd = calloc(MAX_TSD+1, sizeof(void*));
-		worker_sem[i] = MSG_sem_init(0);
+		worker_runner[i].sem = MSG_sem_init(0);
 		tsd[0] = (void*)(uintptr_t) i;
-		worker_runner[i] = MSG_process_create_with_arguments(s, task_execute, tsd, _starpu_simgrid_get_host_by_worker(_starpu_get_worker_struct(i)), 0, NULL);
+		worker_runner[i].runner = MSG_process_create_with_arguments(s, task_execute, tsd, _starpu_simgrid_get_host_by_worker(_starpu_get_worker_struct(i)), 0, NULL);
 	}
 }
 
@@ -343,16 +344,17 @@ void _starpu_simgrid_deinit(void)
 	}
 	for (i = 0; i < starpu_worker_get_count(); i++)
 	{
-		MSG_sem_release(worker_sem[i]);
+		struct worker_runner *w = &worker_runner[i];
+		MSG_sem_release(w->sem);
 #if SIMGRID_VERSION_MAJOR > 3 || (SIMGRID_VERSION_MAJOR == 3 && SIMGRID_VERSION_MINOR >= 14)
-		MSG_process_join(worker_runner[i], 1000000);
+		MSG_process_join(w->runner, 1000000);
 #else
 		MSG_process_sleep(1);
 #endif
-		MSG_sem_destroy(worker_sem[i]);
+		MSG_sem_destroy(w->sem);
+		STARPU_ASSERT(w->first_task == NULL);
+		STARPU_ASSERT(w->last_task == NULL);
 		starpu_pthread_queue_destroy(&_starpu_simgrid_task_queue[i]);
-		STARPU_ASSERT(first_task[i] == NULL);
-		STARPU_ASSERT(last_task[i] == NULL);
 	}
 #ifdef HAVE_MSG_PROCESS_ATTACH
 	if (simgrid_started == 2)
@@ -386,18 +388,20 @@ static int task_execute(int argc STARPU_ATTRIBUTE_UNUSED, char *argv[] STARPU_AT
 	MSG_process_sleep(0.000001);
 
 	unsigned workerid = (uintptr_t) starpu_pthread_getspecific(0);
+	struct worker_runner *w = &worker_runner[workerid];
+
 	_STARPU_DEBUG("worker %u started\n", workerid);
 	while (1) {
 		struct task *task;
 
-		MSG_sem_acquire(worker_sem[workerid]);
+		MSG_sem_acquire(w->sem);
 		if (!runners_running)
 			break;
 
-		task = first_task[workerid];
-		first_task[workerid] = task->next;
-		if (last_task[workerid] == task)
-			last_task[workerid] = NULL;
+		task = w->first_task;
+		w->first_task = task->next;
+		if (w->last_task == task)
+			w->last_task = NULL;
 
 		_STARPU_DEBUG("task %p started\n", task);
 		MSG_task_execute(task->task);
@@ -417,7 +421,7 @@ static int task_execute(int argc STARPU_ATTRIBUTE_UNUSED, char *argv[] STARPU_AT
 /* Wait for completion of all asynchronous tasks for this worker */
 void _starpu_simgrid_wait_tasks(int workerid)
 {
-	struct task *task = last_task[workerid];
+	struct task *task = worker_runner[workerid].last_task;
 	if (!task)
 		return;
 
@@ -476,6 +480,7 @@ void _starpu_simgrid_submit_job(int workerid, struct _starpu_job *j, struct star
 	{
 		/* Asynchronous execution */
 		struct task *task;
+		struct worker_runner *w = &worker_runner[workerid];
 		_STARPU_MALLOC(task, sizeof(*task));
 		task->task = simgrid_task;
 		task->finished = finished;
@@ -484,19 +489,19 @@ void _starpu_simgrid_submit_job(int workerid, struct _starpu_job *j, struct star
 		/* Sleep 10µs for the GPU task queueing */
 		if (_starpu_simgrid_queue_malloc_cost())
 			MSG_process_sleep(0.000010);
-		if (last_task[workerid])
+		if (w->last_task)
 		{
 			/* Already running a task, queue */
-			last_task[workerid]->next = task;
-			last_task[workerid] = task;
+			w->last_task->next = task;
+			w->last_task = task;
 		}
 		else
 		{
-			STARPU_ASSERT(!first_task[workerid]);
-			first_task[workerid] = task;
-			last_task[workerid] = task;
+			STARPU_ASSERT(!w->first_task);
+			w->first_task = task;
+			w->last_task = task;
 		}
-		MSG_sem_release(worker_sem[workerid]);
+		MSG_sem_release(w->sem);
 	}
 }