[dpdk-dev] [PATCH v5 09/12] mbuf: allow to clone an indirect mbuf

Olivier Matz olivier.matz at 6wind.com
Tue Apr 21 11:55:19 CEST 2015


Remove one limitation of rte_pktmbuf_attach(): "mbuf we're attaching to
must be direct".

Now, when we attach to an indirect mbuf:
- copy the all relevant fields (addr, len, offload, ...) as before
- get the pointer to the mbuf that embeds the data buffer (direct mbuf),
  and increase the reference counter of this one.

When detaching the mbuf, we can retrieve this direct mbuf as the pointer
is determined from the buffer address.

Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
 lib/librte_mbuf/rte_mbuf.h | 46 ++++++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 5c01c5b..df54a46 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -799,43 +799,49 @@ static inline struct rte_mbuf *rte_pktmbuf_alloc(struct rte_mempool *mp)
  * After attachment we refer the mbuf we attached as 'indirect',
  * while mbuf we attached to as 'direct'.
  * Right now, not supported:
- *  - attachment to indirect mbuf (e.g. - md  has to be direct).
  *  - attachment for already indirect mbuf (e.g. - mi has to be direct).
  *  - mbuf we trying to attach (mi) is used by someone else
  *    e.g. it's reference counter is greater then 1.
  *
  * @param mi
  *   The indirect packet mbuf.
- * @param md
- *   The direct packet mbuf.
+ * @param m
+ *   The packet mbuf we're attaching to.
  */
-static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *md)
+static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *m)
 {
-	RTE_MBUF_ASSERT(RTE_MBUF_DIRECT(md) &&
-	    RTE_MBUF_DIRECT(mi) &&
+	struct rte_mbuf *md;
+
+	RTE_MBUF_ASSERT(RTE_MBUF_DIRECT(mi) &&
 	    rte_mbuf_refcnt_read(mi) == 1);
 
+	/* if m is not direct, get the mbuf that embeds the data */
+	if (RTE_MBUF_DIRECT(m))
+		md = m;
+	else
+		md = rte_mbuf_from_indirect(m);
+
 	rte_mbuf_refcnt_update(md, 1);
-	mi->buf_physaddr = md->buf_physaddr;
-	mi->buf_addr = md->buf_addr;
-	mi->buf_len = md->buf_len;
-
-	mi->next = md->next;
-	mi->data_off = md->data_off;
-	mi->data_len = md->data_len;
-	mi->port = md->port;
-	mi->vlan_tci = md->vlan_tci;
-	mi->tx_offload = md->tx_offload;
-	mi->hash = md->hash;
+	mi->buf_physaddr = m->buf_physaddr;
+	mi->buf_addr = m->buf_addr;
+	mi->buf_len = m->buf_len;
+
+	mi->next = m->next;
+	mi->data_off = m->data_off;
+	mi->data_len = m->data_len;
+	mi->port = m->port;
+	mi->vlan_tci = m->vlan_tci;
+	mi->tx_offload = m->tx_offload;
+	mi->hash = m->hash;
 
 	mi->next = NULL;
 	mi->pkt_len = mi->data_len;
 	mi->nb_segs = 1;
-	mi->ol_flags = md->ol_flags | IND_ATTACHED_MBUF;
-	mi->packet_type = md->packet_type;
+	mi->ol_flags = m->ol_flags | IND_ATTACHED_MBUF;
+	mi->packet_type = m->packet_type;
 
 	__rte_mbuf_sanity_check(mi, 1);
-	__rte_mbuf_sanity_check(md, 0);
+	__rte_mbuf_sanity_check(m, 0);
 }
 
 /**
-- 
2.1.4



More information about the dev mailing list