From 01944e4c90993b78bcbf4df1609490d730f856d2 Mon Sep 17 00:00:00 2001
From: Olivier Matz <olivier.matz@6wind.com>
Date: Wed, 8 Jan 2020 16:19:15 +0100
Subject: [PATCH] alloc largest

---
 lib/librte_mempool/rte_mempool.c | 42 +++++++++++++++++---------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index b05b417d26..1cb19f46e6 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -480,6 +480,7 @@ rte_mempool_populate_default(struct rte_mempool *mp)
 	unsigned mz_id, n;
 	int ret;
 	bool need_iova_contig_obj;
+	size_t max_alloc_size = SIZE_MAX;
 
 	ret = mempool_ops_alloc_once(mp);
 	if (ret != 0)
@@ -559,29 +560,32 @@ rte_mempool_populate_default(struct rte_mempool *mp)
 		if (min_chunk_size == (size_t)mem_size)
 			mz_flags |= RTE_MEMZONE_IOVA_CONTIG;
 
-		mz = rte_memzone_reserve_aligned(mz_name, mem_size,
+		/* Allocate a memzone, reducing size be 2 on failure */
+		do {
+			mz = rte_memzone_reserve_aligned(
+				mz_name, RTE_MIN((size_t)mem_size, max_alloc_size),
 				mp->socket_id, mz_flags, align);
 
-		/* don't try reserving with 0 size if we were asked to reserve
-		 * IOVA-contiguous memory.
-		 */
-		if (min_chunk_size < (size_t)mem_size && mz == NULL) {
-			/* not enough memory, retry with the biggest zone we
-			 * have
+			/* don't try with a smaller size if we were asked to
+			 * reserve IOVA-contiguous memory.
 			 */
-			mz = rte_memzone_reserve_aligned(mz_name, 0,
-					mp->socket_id, mz_flags, align);
-		}
-		if (mz == NULL) {
-			ret = -rte_errno;
-			goto fail;
-		}
+			if (min_chunk_size >= (size_t)mem_size && mz == NULL) {
+				ret = -rte_errno;
+				goto fail;
+			}
 
-		if (mz->len < min_chunk_size) {
-			rte_memzone_free(mz);
-			ret = -ENOMEM;
-			goto fail;
-		}
+			if (mz == NULL && rte_errno == ENOMEM) {
+				max_alloc_size = RTE_MIN(max_alloc_size,
+							(size_t)mem_size) / 2;
+				if (max_alloc_size < min_chunk_size) {
+					ret = -ENOMEM;
+					goto fail;
+				}
+			} else if (mz == NULL) {
+				ret = -rte_errno;
+				goto fail;
+			}
+		} while (mz == NULL);
 
 		if (need_iova_contig_obj)
 			iova = mz->iova;
-- 
2.20.1