X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Flibrte_mempool%2Frte_mempool_ops_default.c;h=f6aea7662663d57135d8b0fa229846614a6b1595;hb=eba11e36461404109cfe9ed0c5daaa3e80725122;hp=fd63ca137cd3b5abce184820adc1f6cce530b099;hpb=fd943c764a63e5ed4ec4df6ca78e5d7fa8835d4d;p=dpdk.git

diff --git a/lib/librte_mempool/rte_mempool_ops_default.c b/lib/librte_mempool/rte_mempool_ops_default.c
index fd63ca137c..f6aea76626 100644
--- a/lib/librte_mempool/rte_mempool_ops_default.c
+++ b/lib/librte_mempool/rte_mempool_ops_default.c
@@ -12,16 +12,51 @@ rte_mempool_op_calc_mem_size_default(const struct rte_mempool *mp,
 				     size_t *min_chunk_size, size_t *align)
 {
 	size_t total_elt_sz;
+	size_t obj_per_page, pg_sz, objs_in_last_page;
 	size_t mem_size;
 
 	total_elt_sz = mp->header_size + mp->elt_size + mp->trailer_size;
+	if (total_elt_sz == 0) {
+		mem_size = 0;
+	} else if (pg_shift == 0) {
+		mem_size = total_elt_sz * obj_num;
+	} else {
+		pg_sz = (size_t)1 << pg_shift;
+		obj_per_page = pg_sz / total_elt_sz;
+		if (obj_per_page == 0) {
+			/*
+			 * Note that if object size is bigger than page size,
+			 * then it is assumed that pages are grouped in subsets
+			 * of physically continuous pages big enough to store
+			 * at least one object.
+			 */
+			mem_size =
+				RTE_ALIGN_CEIL(total_elt_sz, pg_sz) * obj_num;
+		} else {
+			/* In the best case, the allocator will return a
+			 * page-aligned address. For example, with 5 objs,
+			 * the required space is as below:
+			 *  |     page0     |     page1     |  page2 (last) |
+			 *  |obj0 |obj1 |xxx|obj2 |obj3 |xxx|obj4|
+			 *  <------------- mem_size ------------->
+			 */
+			objs_in_last_page = ((obj_num - 1) % obj_per_page) + 1;
+			/* room required for the last page */
+			mem_size = objs_in_last_page * total_elt_sz;
+			/* room required for other pages */
+			mem_size += ((obj_num - objs_in_last_page) /
+				obj_per_page) << pg_shift;
 
-	mem_size = rte_mempool_calc_mem_size_helper(obj_num, total_elt_sz,
-						    pg_shift);
-
-	*min_chunk_size = RTE_MAX((size_t)1 << pg_shift, total_elt_sz);
+			/* In the worst case, the allocator returns a
+			 * non-aligned pointer, wasting up to
+			 * total_elt_sz. Add a margin for that.
+			 */
+			 mem_size += total_elt_sz - 1;
+		}
+	}
 
-	*align = RTE_MAX((size_t)RTE_CACHE_LINE_SIZE, (size_t)1 << pg_shift);
+	*min_chunk_size = total_elt_sz;
+	*align = RTE_CACHE_LINE_SIZE;
 
 	return mem_size;
 }