[dpdk-dev] [PATCH] rte_mbuf: bulk allocation and freeing functions + unittest

[vadim.suraev at gmail.com]

From: "vadim.suraev at gmail.com" <vadim.suraev at gmail.com>

- an API function to allocate a bulk of rte_mbufs
- an API function to free a bulk of rte_mbufs
- an API function to free a chained rte_mbuf
- unittest for aboce

Signed-off-by: vadim.suraev at gmail.com <vadim.suraev at gmail.com>
---
 app/test/test_mbuf.c       |   73 ++++++++++++++++++++++++++++++++
 lib/librte_mbuf/rte_mbuf.h |  101 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 174 insertions(+)

diff --git a/app/test/test_mbuf.c b/app/test/test_mbuf.c
index 1ff66cb..a557705 100644
--- a/app/test/test_mbuf.c
+++ b/app/test/test_mbuf.c
@@ -405,6 +405,67 @@ test_pktmbuf_pool(void)
 	return ret;
 }
 
+/* test pktmbuf bulk allocation and freeing
+*/
+static int
+test_pktmbuf_pool_bulk(void)
+{
+	unsigned i;
+	unsigned mbufs_to_allocate = NB_MBUF - 32; /* size of mempool - size of local cache, otherwise may fail */
+	struct rte_mbuf *m[mbufs_to_allocate];
+	int ret = 0;
+	unsigned mbuf_count_before_allocation = rte_mempool_count(pktmbuf_pool);
+
+	for (i=0; i<mbufs_to_allocate; i++)
+		m[i] = NULL;
+	/* alloc NB_MBUF-32 mbufs */
+	if ((ret = rte_pktmbuf_alloc_bulk(pktmbuf_pool, m, mbufs_to_allocate))) {
+		printf("cannot allocate %d mbufs bulk mempool_count=%d ret=%d\n", mbufs_to_allocate, rte_mempool_count(pktmbuf_pool), ret);
+		return -1;
+	}
+	if ((rte_mempool_count(pktmbuf_pool) + mbufs_to_allocate) != mbuf_count_before_allocation) {
+		printf("mempool count %d + allocated %d != initial %d\n",
+			rte_mempool_count(pktmbuf_pool), mbufs_to_allocate, mbuf_count_before_allocation);
+		return -1;
+	}
+	/* free them */
+	rte_pktmbuf_bulk_free(m, mbufs_to_allocate);
+	
+	if (rte_mempool_count(pktmbuf_pool)  != mbuf_count_before_allocation) {
+		printf("mempool count %d != initial %d\n",
+			rte_mempool_count(pktmbuf_pool), mbuf_count_before_allocation);
+		return -1;
+	}
+	for (i=0; i<mbufs_to_allocate; i++)
+		m[i] = NULL;
+
+	/* alloc NB_MBUF-32 mbufs */
+	if ((ret = rte_pktmbuf_alloc_bulk(pktmbuf_pool, m, mbufs_to_allocate))) {
+		printf("cannot allocate %d mbufs bulk mempool_count=%d ret=%d\n", mbufs_to_allocate, rte_mempool_count(pktmbuf_pool), ret);
+		return -1;
+	}
+	if ((rte_mempool_count(pktmbuf_pool) + mbufs_to_allocate) != mbuf_count_before_allocation) {
+		printf("mempool count %d + allocated %d != initial %d\n",
+			rte_mempool_count(pktmbuf_pool), mbufs_to_allocate, mbuf_count_before_allocation);
+		return -1;
+	}
+
+	/* chain it */
+	for (i=0; i< mbufs_to_allocate - 1; i++) {
+		m[i]->next = m[i + 1];
+		m[0]->nb_segs++;
+	}
+	/* free them */
+	rte_pktmbuf_free_chain(m[0]);
+	
+	if (rte_mempool_count(pktmbuf_pool)  != mbuf_count_before_allocation) {
+		printf("mempool count %d != initial %d\n",
+			rte_mempool_count(pktmbuf_pool), mbuf_count_before_allocation);
+		return -1;
+	}
+	return ret;
+}
+
 /*
  * test that the pointer to the data on a packet mbuf is set properly
  */
@@ -790,6 +851,18 @@ test_mbuf(void)
 		return -1;
 	}
 
+	/* test bulk allocation and freeing */
+	if (test_pktmbuf_pool_bulk() < 0) {
+		printf("test_pktmbuf_pool_bulk() failed\n");
+		return -1;
+	}
+
+	/* once again to ensure all mbufs were freed */
+	if (test_pktmbuf_pool_bulk() < 0) {
+		printf("test_pktmbuf_pool_bulk() failed\n");
+		return -1;
+	}
+
 	/* test that the pointer to the data on a packet mbuf is set properly */
 	if (test_pktmbuf_pool_ptr() < 0) {
 		printf("test_pktmbuf_pool_ptr() failed\n");
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 17ba791..482920e 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -825,6 +825,107 @@ static inline void rte_pktmbuf_free(struct rte_mbuf *m)
 }
 
 /**
+ * Allocates a bulk of mbufs, initiates refcnt and resets
+ *
+ * @param pool
+ *    memory pool to allocate from
+ * @param mbufs
+ *    Array of pointers to mbuf
+ * @param count
+ *    Array size
+ */
+static inline int rte_pktmbuf_alloc_bulk(struct rte_mempool *pool, struct rte_mbuf **mbufs, unsigned count)
+{
+	unsigned idx;
+	int rc = 0;
+
+	if (unlikely(rc = rte_mempool_get_bulk(pool, (void **)mbufs, count))) {
+		return rc;
+	}
+
+	for (idx = 0; idx < count; idx++) {
+		RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(mbufs[idx]) == 0);
+		rte_mbuf_refcnt_set(mbufs[idx], 1);
+		rte_pktmbuf_reset(mbufs[idx]);
+	}
+	return rc;
+}
+
+/**
+ * Frees a bulk of mbufs into its original mempool.
+ * It is responsibility of caller to update and check refcnt
+ * as well as to check for attached mbufs to be freed
+ *
+ * @param mbufs
+ *    Array of pointers to mbuf
+ * @param count
+ *    Array size
+ */
+
+static inline void rte_pktmbuf_bulk_raw_free(struct rte_mbuf **mbufs, unsigned count)
+{
+	if (unlikely(count == 0))
+		return;
+	rte_mempool_put_bulk(mbufs[0]->pool, (void **)mbufs, count);
+}
+
+/**
+ * Frees a bulk of mbufs into its original mempool.
+ * This function assumes refcnt has been already decremented
+ * as well as the freed mbufs are direct
+ *
+ * @param mbufs
+ *    Array of pointers to mbuf
+ * @param count
+ *    Array size
+ */
+
+static inline void rte_pktmbuf_bulk_free(struct rte_mbuf **mbufs, unsigned count)
+{
+	if (unlikely(count == 0))
+		return;
+	unsigned idx;
+
+	for(idx = 0; idx < count; idx++) {
+		rte_mbuf_refcnt_update(mbufs[idx], -1);
+		RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(mbufs[idx]) == 0);
+	}
+	rte_mempool_put_bulk(mbufs[0]->pool, (void **)mbufs, count);
+}
+
+/**
+ * Frees chained (scattered) mbufs into its original mempool(s).
+ *
+ * @param head
+ *    The head of mbufs to be freed chain
+ */
+
+static inline void rte_pktmbuf_free_chain(struct rte_mbuf *head)
+{
+	if (likely(head != NULL)) {
+		struct rte_mbuf *mbufs[head->nb_segs];
+		unsigned mbufs_count = 0;
+		struct rte_mbuf *next;
+
+		while (head) {
+			next = head->next;
+			head->next = NULL; 
+			if (likely(NULL != (head = __rte_pktmbuf_prefree_seg(head)))) {
+				RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(head) == 0);
+				if (likely((!mbufs_count) || (head->pool == mbufs[0]->pool)))
+					mbufs[mbufs_count++] = head;
+				else {
+					rte_pktmbuf_bulk_raw_free(mbufs, mbufs_count);
+					mbufs_count = 0;
+				}
+			}
+			head = next;
+		}
+		rte_pktmbuf_bulk_raw_free(mbufs, mbufs_count);
+	}
+}
+
+/**
  * Creates a "clone" of the given packet mbuf.
  *
  * Walks through all segments of the given packet mbuf, and for each of them:
-- 
1.7.9.5