Fix asynchronous prefetch: we also need to notify data dependencies in that case. Allocate the wrapper structure dynamically to permit asynchronous termination. Permit prefetch in callbacks and codelets

src/datawizard/user_interactions.c

@@ -196,7 +196,7 @@ int starpu_data_acquire(starpu_data_handle handle, starpu_access_mode mode)
 	STARPU_ASSERT(handle);
         _STARPU_LOG_IN();
 
-	/* it is forbidden to call this function from a callback or a codelet */
+	/* unless asynchronous, it is forbidden to call this function from a callback or a codelet */
 	if (STARPU_UNLIKELY(!_starpu_worker_may_perform_blocking_calls())) {
                 _STARPU_LOG_OUT_TAG("EDEADLK");
 		return -EDEADLK;
@@ -299,12 +299,12 @@ static void _prefetch_data_on_node(void *arg)
 		wrapper->finished = 1;
 		PTHREAD_COND_SIGNAL(&wrapper->cond);
 		PTHREAD_MUTEX_UNLOCK(&wrapper->lock);
-
-		_starpu_spin_lock(&handle->header_lock);
-		_starpu_notify_data_dependencies(handle);
-		_starpu_spin_unlock(&handle->header_lock);
 	}
 
+	_starpu_spin_lock(&handle->header_lock);
+	_starpu_notify_data_dependencies(handle);
+	_starpu_spin_unlock(&handle->header_lock);
+
 }
 
 static
@@ -313,40 +313,40 @@ int _starpu_prefetch_data_on_node_with_mode(starpu_data_handle handle, unsigned
 	STARPU_ASSERT(handle);
 
 	/* it is forbidden to call this function from a callback or a codelet */
-	if (STARPU_UNLIKELY(!_starpu_worker_may_perform_blocking_calls()))
+	if (STARPU_UNLIKELY(!async && !_starpu_worker_may_perform_blocking_calls()))
 		return -EDEADLK;
 
-	struct user_interaction_wrapper wrapper =
-	{
-		.handle = handle,
-		.node = node,
-		.async = async,
-		.cond = PTHREAD_COND_INITIALIZER,
-		.lock = PTHREAD_MUTEX_INITIALIZER,
-		.finished = 0
-	};
+	struct user_interaction_wrapper *wrapper = (struct user_interaction_wrapper *) malloc(sizeof(*wrapper));
+
+	wrapper->handle = handle;
+	wrapper->node = node;
+	wrapper->async = async;
+	PTHREAD_COND_INIT(&wrapper->cond, NULL);
+	PTHREAD_MUTEX_INIT(&wrapper->lock, NULL);
+	wrapper->finished = 0;
 
-	if (!_starpu_attempt_to_submit_data_request_from_apps(handle, mode, _prefetch_data_on_node, &wrapper))
+	if (!_starpu_attempt_to_submit_data_request_from_apps(handle, mode, _prefetch_data_on_node, wrapper))
 	{
 		/* we can immediately proceed */
 		struct starpu_data_replicate_s *replicate = &handle->per_node[node];
 		_starpu_fetch_data_on_node(handle, replicate, mode, async, NULL, NULL);
 
 		/* remove the "lock"/reference */
-		if (!async)
-		{
-			_starpu_spin_lock(&handle->header_lock);
+
+		_starpu_spin_lock(&handle->header_lock);
+		if (!async) {
 			replicate->refcnt--;
 			STARPU_ASSERT(replicate->refcnt >= 0);
-			_starpu_notify_data_dependencies(handle);
-			_starpu_spin_unlock(&handle->header_lock);
 		}
+		_starpu_notify_data_dependencies(handle);
+		_starpu_spin_unlock(&handle->header_lock);
+
 	}
 	else if (!async) {
-		PTHREAD_MUTEX_LOCK(&wrapper.lock);
-		while (!wrapper.finished)
-			PTHREAD_COND_WAIT(&wrapper.cond, &wrapper.lock);
-		PTHREAD_MUTEX_UNLOCK(&wrapper.lock);
+		PTHREAD_MUTEX_LOCK(&wrapper->lock);
+		while (!wrapper->finished)
+			PTHREAD_COND_WAIT(&wrapper->cond, &wrapper->lock);
+		PTHREAD_MUTEX_UNLOCK(&wrapper->lock);
 	}
 
 	return 0;

tests/microbenchs/prefetch_data_on_node.c

@@ -1,6 +1,6 @@
 /* StarPU --- Runtime system for heterogeneous multicore architectures.
  *
- * Copyright (C) 2009, 2010  Université de Bordeaux 1
+ * Copyright (C) 2009-2011  Université de Bordeaux 1
  * Copyright (C) 2010, 2011  Centre National de la Recherche Scientifique
  *
  * StarPU is free software; you can redistribute it and/or modify
@@ -26,34 +26,16 @@
 
 #define VECTORSIZE	1024
 
-static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
-
-static unsigned finished = 0;
-
-static unsigned cnt;
-
 starpu_data_handle v_handle;
 static unsigned *v;
 
 static void callback(void *arg)
 {
-	unsigned res = STARPU_ATOMIC_ADD(&cnt, -1);
-
-	//fprintf(stderr, "res ...%d\n", res);
-	//fflush(stderr);
+	unsigned node = (unsigned)(uintptr_t) arg;
 
-	if (res == 0)
-	{
-		pthread_mutex_lock(&mutex);
-		finished = 1;
-		pthread_cond_signal(&cond);
-		pthread_mutex_unlock(&mutex);
-	}
+	starpu_data_prefetch_on_node(v_handle, node, 1);
 }
 
-
-
 static void codelet_null(void *descr[], __attribute__ ((unused)) void *_args)
 {
 //	fprintf(stderr, "pif\n");
@@ -95,8 +77,6 @@ int main(int argc, char **argv)
 
 	unsigned nworker = starpu_worker_get_count();
 
-	cnt = nworker*N;
-
 	unsigned iter, worker;
 	for (iter = 0; iter < N; iter++)
 	{
@@ -113,10 +93,33 @@ int main(int argc, char **argv)
 			task->buffers[0].handle = v_handle;
 			task->buffers[0].mode = select_random_mode();
 
+			task->synchronous = 1;
+
+			int ret = starpu_task_submit(task);
+			if (ret == -ENODEV)
+				goto enodev;
+		}
+	}
+
+	for (iter = 0; iter < N; iter++)
+	{
+		for (worker = 0; worker < nworker; worker++)
+		{
+			/* asynchronous prefetch */
+			unsigned node = starpu_worker_get_memory_node(worker);
+			starpu_data_prefetch_on_node(v_handle, node, 1);
+
+			/* execute a task */
+			struct starpu_task *task = starpu_task_create();
+			task->cl = &cl;
+
+			task->buffers[0].handle = v_handle;
+			task->buffers[0].mode = select_random_mode();
+
 			task->callback_func = callback;
-			task->callback_arg = NULL;
+			task->callback_arg = (void*)(uintptr_t) starpu_worker_get_memory_node((worker+1)%nworker);
 
-			task->synchronous = 1;
+			task->synchronous = 0;
 
 			int ret = starpu_task_submit(task);
 			if (ret == -ENODEV)
@@ -124,10 +127,7 @@ int main(int argc, char **argv)
 		}
 	}
 
-	pthread_mutex_lock(&mutex);
-	if (!finished)
-		pthread_cond_wait(&cond, &mutex);
-	pthread_mutex_unlock(&mutex);
+	starpu_task_wait_for_all();
 
 	starpu_free(v);
 	starpu_shutdown();

tools/gdbinit

@@ -187,9 +187,9 @@ define starpu-print-data
   printf "Requester tasks\n"
   set $requesterlist = $data->req_list._head
   while $requesterlist != 0x0
-    print "mode: "
+    printf "mode: "
     starpu-print-mode $requesterlist->mode
-    print "\n"
+    printf "\n"
     starpu-print-job $requesterlist->j
     set $requesterlist = $requesterlist->_next
   end
@@ -241,18 +241,7 @@ define starpu-print-requests
     set $request = data_requests[$node]._head
     while $request != 0
       printf " Request %p: handle %p ", $request, $request->handle
-      if ($request->mode & 1)
-        printf "R"
-      end
-      if ($request->mode & 2)
-        printf "W"
-      end
-      if ($request->mode & 4)
-        printf "S"
-      end
-      if ($request->mode & 8)
-        printf "X"
-      end
+      starpu-print-mode $request->mode
       printf "\n"
       set $request = $request->_next
     end