*/
const char *rte_get_tx_ol_flag_name(uint64_t mask);
+/**
+ * Some NICs need at least 2KB buffer to RX standard Ethernet frame without
+ * splitting it into multiple segments.
+ * So, for mbufs that planned to be involved into RX/TX, the recommended
+ * minimal buffer length is 2KB + RTE_PKTMBUF_HEADROOM.
+ */
+#define RTE_MBUF_DEFAULT_DATAROOM 2048
+#define RTE_MBUF_DEFAULT_BUF_SIZE \
+ (RTE_MBUF_DEFAULT_DATAROOM + RTE_PKTMBUF_HEADROOM)
+
/* define a set of marker types that can be used to refer to set points in the
* mbuf */
typedef void *MARKER[0]; /**< generic marker for a point in a structure */
#ifdef RTE_MBUF_REFCNT_ATOMIC
-/**
- * Adds given value to an mbuf's refcnt and returns its new value.
- * @param m
- * Mbuf to update
- * @param value
- * Value to add/subtract
- * @return
- * Updated value
- */
-static inline uint16_t
-rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value)
-{
- return (uint16_t)(rte_atomic16_add_return(&m->refcnt_atomic, value));
-}
-
/**
* Reads the value of an mbuf's refcnt.
* @param m
rte_atomic16_set(&m->refcnt_atomic, new_value);
}
+/**
+ * Adds given value to an mbuf's refcnt and returns its new value.
+ * @param m
+ * Mbuf to update
+ * @param value
+ * Value to add/subtract
+ * @return
+ * Updated value
+ */
+static inline uint16_t
+rte_mbuf_refcnt_update(struct rte_mbuf *m, int16_t value)
+{
+ /*
+ * The atomic_add is an expensive operation, so we don't want to
+ * call it in the case where we know we are the uniq holder of
+ * this mbuf (i.e. ref_cnt == 1). Otherwise, an atomic
+ * operation has to be used because concurrent accesses on the
+ * reference counter can occur.
+ */
+ if (likely(rte_mbuf_refcnt_read(m) == 1)) {
+ rte_mbuf_refcnt_set(m, 1 + value);
+ return 1 + value;
+ }
+
+ return (uint16_t)(rte_atomic16_add_return(&m->refcnt_atomic, value));
+}
+
#else /* ! RTE_MBUF_REFCNT_ATOMIC */
/**
* 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->priv_size = md->priv_size;
-
- 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->priv_size = m->priv_size;
+ 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);
}
/**
{
__rte_mbuf_sanity_check(m, 0);
- /*
- * Check to see if this is the last reference to the mbuf.
- * Note: the double check here is deliberate. If the ref_cnt is "atomic"
- * the call to "refcnt_update" is a very expensive operation, so we
- * don't want to call it in the case where we know we are the holder
- * of the last reference to this mbuf i.e. ref_cnt == 1.
- * If however, ref_cnt != 1, it's still possible that we may still be
- * the final decrementer of the count, so we need to check that
- * result also, to make sure the mbuf is freed properly.
- */
- if (likely (rte_mbuf_refcnt_read(m) == 1) ||
- likely (rte_mbuf_refcnt_update(m, -1) == 0)) {
-
- rte_mbuf_refcnt_set(m, 0);
+ if (likely(rte_mbuf_refcnt_update(m, -1) == 0)) {
/* if this is an indirect mbuf, then
* - detach mbuf
git.droids-corp.org / dpdk.git / blobdiff