[dpdk-dev] [PATCH v10 1/5] mempool: populate mempool with the page sized chunks

[<vattunuru@marvell.com>]

From: Vamsi Attunuru <vattunuru@marvell.com>

Patch adds a routine to populate mempool from page aligned and
page sized chunks of memory to ensure memory objs do not fall
across the page boundaries. It's useful for applications that
require physically contiguous mbuf memory while running in
IOVA=VA mode.

Signed-off-by: Vamsi Attunuru <vattunuru@marvell.com>
Signed-off-by: Kiran Kumar K <kirankumark@marvell.com>
---
 lib/librte_mempool/rte_mempool.c           | 69 ++++++++++++++++++++++++++++++
 lib/librte_mempool/rte_mempool.h           | 20 +++++++++
 lib/librte_mempool/rte_mempool_version.map |  1 +
 3 files changed, 90 insertions(+)

diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
index 7260ce0..0683750 100644
--- a/lib/librte_mempool/rte_mempool.c
+++ b/lib/librte_mempool/rte_mempool.c
@@ -414,6 +414,75 @@ rte_mempool_populate_virt(struct rte_mempool *mp, char *addr,
 	return ret;
 }
 
+/* Function to populate mempool from page sized mem chunks, allocate page size
+ * of memory in memzone and populate them. Return the number of objects added,
+ * or a negative value on error.
+ */
+int
+rte_mempool_populate_from_pg_sz_chunks(struct rte_mempool *mp)
+{
+	char mz_name[RTE_MEMZONE_NAMESIZE];
+	size_t align, pg_sz, pg_shift;
+	const struct rte_memzone *mz;
+	unsigned int mz_id, n;
+	size_t min_chunk_size;
+	int ret;
+
+	ret = mempool_ops_alloc_once(mp);
+	if (ret != 0)
+		return ret;
+
+	if (mp->nb_mem_chunks != 0)
+		return -EEXIST;
+
+	pg_sz = get_min_page_size(mp->socket_id);
+	pg_shift = rte_bsf32(pg_sz);
+
+	for (mz_id = 0, n = mp->size; n > 0; mz_id++, n -= ret) {
+
+		ret = rte_mempool_ops_calc_mem_size(mp, n,
+				pg_shift, &min_chunk_size, &align);
+
+		if (ret < 0)
+			goto fail;
+
+		if (min_chunk_size > pg_sz) {
+			ret = -EINVAL;
+			goto fail;
+		}
+
+		ret = snprintf(mz_name, sizeof(mz_name),
+			RTE_MEMPOOL_MZ_FORMAT "_%d", mp->name, mz_id);
+		if (ret < 0 || ret >= (int)sizeof(mz_name)) {
+			ret = -ENAMETOOLONG;
+			goto fail;
+		}
+
+		mz = rte_memzone_reserve_aligned(mz_name, min_chunk_size,
+				mp->socket_id, 0, align);
+
+		if (mz == NULL) {
+			ret = -rte_errno;
+			goto fail;
+		}
+
+		ret = rte_mempool_populate_iova(mp, mz->addr,
+				mz->iova, mz->len,
+				rte_mempool_memchunk_mz_free,
+				(void *)(uintptr_t)mz);
+		if (ret < 0) {
+			rte_memzone_free(mz);
+			goto fail;
+		}
+	}
+
+	return mp->size;
+
+fail:
+	rte_mempool_free_memchunks(mp);
+	return ret;
+}
+
 /* Default function to populate the mempool: allocate memory in memzones,
  * and populate them. Return the number of objects added, or a negative
  * value on error.
diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
index 8053f7a..2f5126e 100644
--- a/lib/librte_mempool/rte_mempool.h
+++ b/lib/librte_mempool/rte_mempool.h
@@ -1062,6 +1062,26 @@ rte_mempool_populate_virt(struct rte_mempool *mp, char *addr,
 	void *opaque);
 
 /**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Add memory from page sized memzones for objects in the pool at init
+ *
+ * This is the function used to populate the mempool with page aligned and
+ * page sized memzone memory to avoid spreading object memory across two pages
+ * and to ensure all mempool objects reside on the page memory.
+ *
+ * @param mp
+ *   A pointer to the mempool structure.
+ * @return
+ *   The number of objects added on success.
+ *   On error, the chunk is not added in the memory list of the
+ *   mempool and a negative errno is returned.
+ */
+__rte_experimental
+int rte_mempool_populate_from_pg_sz_chunks(struct rte_mempool *mp);
+
+/**
  * Add memory for objects in the pool at init
  *
  * This is the default function used by rte_mempool_create() to populate
diff --git a/lib/librte_mempool/rte_mempool_version.map b/lib/librte_mempool/rte_mempool_version.map
index 17cbca4..9a6fe65 100644
--- a/lib/librte_mempool/rte_mempool_version.map
+++ b/lib/librte_mempool/rte_mempool_version.map
@@ -57,4 +57,5 @@ EXPERIMENTAL {
 	global:
 
 	rte_mempool_ops_get_info;
+	rte_mempool_populate_from_pg_sz_chunks;
 };
-- 
2.8.4