Merge pull request #938 from jean-m-cyr/master

Reduce potential dataman memory fragmentation

1 files changed, 23 insertions, 6 deletions

diff --git a/src/modules/dataman/dataman.c b/src/modules/dataman/dataman.c
index 5f3ada0cd..1a65313e8 100644
--- a/src/modules/dataman/dataman.c
+++ b/src/modules/dataman/dataman.c
@@ -76,7 +76,8 @@ typedef enum {
 typedef struct {
 	sq_entry_t link;	/**< list linkage */
 	sem_t wait_sem;
-	dm_function_t func;
+	unsigned char first;
+	unsigned char func;
 	ssize_t result;
 	union {
 		struct {
@@ -101,6 +102,8 @@ typedef struct {
 	};
 } work_q_item_t;
 
+const size_t k_work_item_allocation_chunk_size = 8;
+
 /* Usage statistics */
 static unsigned g_func_counts[dm_number_of_funcs];
 
@@ -178,9 +181,23 @@ create_work_item(void)
 
 	unlock_queue(&g_free_q);
 
-	/* If we there weren't any free items then obtain memory for a new one */
-	if (item == NULL)
-		item = (work_q_item_t *)malloc(sizeof(work_q_item_t));
+	/* If we there weren't any free items then obtain memory for a new ones */
+	if (item == NULL) {
+		item = (work_q_item_t *)malloc(k_work_item_allocation_chunk_size * sizeof(work_q_item_t));
+		if (item) {
+			item->first = 1;
+			lock_queue(&g_free_q);
+			for (int i = 1; i < k_work_item_allocation_chunk_size; i++) {
+				(item + i)->first = 0;
+				sq_addfirst(&(item + i)->link, &(g_free_q.q));
+			}
+			/* Update the queue size and potentially the maximum queue size */
+			g_free_q.size += k_work_item_allocation_chunk_size - 1;
+			if (g_free_q.size > g_free_q.max_size)
+				g_free_q.max_size = g_free_q.size;
+			unlock_queue(&g_free_q);
+		}
+	}
 
 	/* If we got one then lock the item*/
 	if (item)
@@ -718,8 +735,8 @@ task_main(int argc, char *argv[])
 	for (;;) {
 		if ((work = (work_q_item_t *)sq_remfirst(&(g_free_q.q))) == NULL)
 			break;
-
-		free(work);
+		if (work->first)
+			free(work);
 	}
 
 	destroy_q(&g_work_q);