harmonize _starpu_handle_node_data_requests and _starpu_handle_node_prefetch_requests

src/datawizard/data_request.c

@@ -461,8 +461,8 @@ int _starpu_handle_node_data_requests(unsigned src_node, unsigned may_alloc, uns
 #ifdef STARPU_NON_BLOCKING_DRIVERS
 	/* take all the entries from the request list */
 	if (STARPU_PTHREAD_MUTEX_TRYLOCK(&data_requests_list_mutex[src_node]))
-		/* List is busy, do not bother with it */
 	{
+		/* List is busy, do not bother with it */
 		_starpu_data_request_list_delete(empty_list);
 		return -EBUSY;
 	}
@@ -476,7 +476,6 @@ int _starpu_handle_node_data_requests(unsigned src_node, unsigned may_alloc, uns
 	{
 		/* there is no request */
                 STARPU_PTHREAD_MUTEX_UNLOCK(&data_requests_list_mutex[src_node]);
-
 		_starpu_data_request_list_delete(empty_list);
 		return 0;
 	}
@@ -541,21 +540,22 @@ int _starpu_handle_node_data_requests(unsigned src_node, unsigned may_alloc, uns
 	return ret;
 }
 
-void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc, unsigned *pushed)
+int _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc, unsigned *pushed)
 {
 	struct _starpu_data_request *r;
 	struct _starpu_data_request_list *new_data_requests;
 	struct _starpu_data_request_list *new_prefetch_requests;
 	struct _starpu_data_request_list *empty_list;
+	int ret = 0;
 
 	*pushed = 0;
 
 #ifdef STARPU_NON_BLOCKING_DRIVERS
 	/* This is racy, but not posing problems actually, since we know we
 	 * will come back here to probe again regularly anyway.
-	 * Thus, do not expose this optimization to valgrind */
+	 * Thus, do not expose this optimization to helgrind */
 	if (!RUNNING_ON_VALGRIND && _starpu_data_request_list_empty(prefetch_requests[src_node]))
-		return;
+		return 0;
 #endif
 
 	empty_list = _starpu_data_request_list_new();
@@ -566,7 +566,7 @@ void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc
 	{
 		/* List is busy, do not bother with it */
 		_starpu_data_request_list_delete(empty_list);
-		return;
+		return -EBUSY;
 	}
 #else
 	STARPU_PTHREAD_MUTEX_LOCK(&data_requests_list_mutex[src_node]);
@@ -579,13 +579,14 @@ void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc
 		/* there is no request */
                 STARPU_PTHREAD_MUTEX_UNLOCK(&data_requests_list_mutex[src_node]);
 		_starpu_data_request_list_delete(empty_list);
-		return;
+		return 0;
 	}
 
 	/* There is an entry: we create a new empty list to replace the list of
 	 * requests, and we handle the request(s) one by one in the former
 	 * list, without concurrency issues.*/
 	prefetch_requests[src_node] = empty_list;
+	STARPU_HG_DISABLE_CHECKING(prefetch_requests[src_node]->_head);
 
 	STARPU_PTHREAD_MUTEX_UNLOCK(&data_requests_list_mutex[src_node]);
 
@@ -601,6 +602,7 @@ void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc
 		{
 			/* Too many requests at the same time, skip pushing
 			 * more for now */
+			ret = -EBUSY;
 			break;
 		}
 
@@ -609,6 +611,8 @@ void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc
 		res = starpu_handle_data_request(r, may_alloc, 1);
 		if (res != 0 && res != -EAGAIN)
 		{
+			/* handle is busy, or not enough memory, postpone for now */
+			ret = res;
 			if (r->prefetch)
 				_starpu_data_request_list_push_back(new_prefetch_requests, r);
 			else
@@ -622,7 +626,7 @@ void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc
 		(*pushed)++;
 	}
 
-	while(!_starpu_data_request_list_empty(local_list))
+	while (!_starpu_data_request_list_empty(local_list))
 	{
 		r = _starpu_data_request_list_pop_front(local_list);
 		if (r->prefetch)
@@ -649,6 +653,8 @@ void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc
 	_starpu_data_request_list_delete(new_data_requests);
 	_starpu_data_request_list_delete(new_prefetch_requests);
 	_starpu_data_request_list_delete(local_list);
+
+	return ret;
 }
 
 static int _handle_pending_node_data_requests(unsigned src_node, unsigned force)

src/datawizard/data_request.h

@@ -1,6 +1,6 @@
 /* StarPU --- Runtime system for heterogeneous multicore architectures.
  *
- * Copyright (C) 2009-2010, 2013-2014  Université de Bordeaux
+ * Copyright (C) 2009-2010, 2013-2015  Université de Bordeaux
  * Copyright (C) 2010, 2011, 2013  Centre National de la Recherche Scientifique
  *
  * StarPU is free software; you can redistribute it and/or modify
@@ -111,7 +111,7 @@ void _starpu_deinit_data_request_lists(void);
 void _starpu_post_data_request(struct _starpu_data_request *r, unsigned handling_node);
 /* returns 0 if we have pushed all requests, -EBUSY or -ENOMEM otherwise */
 int _starpu_handle_node_data_requests(unsigned src_node, unsigned may_alloc, unsigned *pushed);
-void _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc, unsigned *pushed);
+int _starpu_handle_node_prefetch_requests(unsigned src_node, unsigned may_alloc, unsigned *pushed);
 
 int _starpu_handle_pending_node_data_requests(unsigned src_node);
 int _starpu_handle_all_pending_node_data_requests(unsigned src_node);