[PATCH] kni: add bulk function to free mbufs

[Sergey Vyazmitinov <s.vyazmitinov@brain4net.com>]

Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Sergey Vyazmitinov <s.vyazmitinov@brain4net.com>
---
v3:
* Fixed issue with possible different mempools in buffer list.
* Fixed issue with wrong rte_pktmbuf_alloc_bulk function return value
processing in the kni_allocate_mbufs.
---
 lib/librte_mbuf/rte_mbuf.h | 49 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 4476d75..69d314f 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -306,6 +306,9 @@ extern "C" {
 /** Alignment constraint of mbuf private area. */
 #define RTE_MBUF_PRIV_ALIGN 8
 
+/** Maximum number of mbufs freed in bulk. */
+#define RTE_MBUF_BULK_FREE 64
+
 /**
  * Get the name of a RX offload flag
  *
@@ -1261,6 +1264,52 @@ static inline void rte_pktmbuf_free(struct rte_mbuf *m)
 }
 
 /**
+ * Free n packets mbuf back into its original mempool.
+ *
+ * Free each mbuf, and all its segments in case of chained buffers. Each
+ * segment is added back into its original mempool.
+ *
+ * @param mp
+ *   The packets mempool.
+ * @param mbufs
+ *   The packets mbufs array to be freed.
+ * @param n
+ *   Number of packets.
+ */
+static inline void rte_pktmbuf_free_bulk(struct rte_mbuf **mbufs,
+		unsigned int n)
+{
+	void *tofree[RTE_MBUF_BULK_FREE];
+	struct rte_mempool *mp = NULL;
+	unsigned int i, count = 0;
+
+	for (i = 0; i < n; i++) {
+		struct rte_mbuf *m, *m_next;
+
+		for (m = mbufs[i]; m; m = m_next) {
+			m_next = m->next;
+
+			if (count > 0 &&
+			    (unlikely(m->pool != mp ||
+				    count == RTE_MBUF_BULK_FREE))) {
+				rte_mempool_put_bulk(mp, tofree, count);
+				count = 0;
+			}
+
+			mp = m->pool;
+
+			if (likely(__rte_pktmbuf_prefree_seg(m) != NULL)) {
+				m->next = NULL;
+				tofree[count++] = m;
+			}
+		}
+	}
+
+	if (likely(count > 0))
+		rte_mempool_put_bulk(mp, tofree, count);
+}
+
+/**
  * Creates a "clone" of the given packet mbuf.
  *
  * Walks through all segments of the given packet mbuf, and for each of them:
-- 
2.7.4