When a bridge of datatype type netdev receives a packet, it copies the
packet from the NIC to a buffer in userspace. Currently, when making
an upcall, the packet is again copied to the upcall's buffer. However,
this extra copy is not necessary when the datapath exists in userspace
as the upcall can directly access the packet data.
This patch eliminates this extra copy of the packet data in most cases.
In cases where the packet may still be used later by callers of
dp_netdev_execute_actions, making a copy of the packet data is still
necessary.
Signed-off-by: Ryan Wilson <wr...@nicira.com>
---
v2: Addressed Jarno's comment to use direct pointer assignment for
upcall->packet instead of ofpbuf_set().
---
lib/dpif-netdev.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 91c83d6..c89ae20 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -2024,7 +2024,6 @@ dp_netdev_input(struct dp_netdev *dp, struct ofpbuf
*packet,
miniflow_hash_5tuple(&key.flow, 0)
% dp->n_handlers,
DPIF_UC_MISS, &key.flow, NULL);
- ofpbuf_delete(packet);
}
}
@@ -2063,7 +2062,6 @@ dp_netdev_output_userspace(struct dp_netdev *dp, struct
ofpbuf *packet,
if (userdata) {
buf_size += NLA_ALIGN(userdata->nla_len);
}
- buf_size += ofpbuf_size(packet);
ofpbuf_init(buf, buf_size);
/* Put ODP flow. */
@@ -2078,15 +2076,14 @@ dp_netdev_output_userspace(struct dp_netdev *dp, struct
ofpbuf *packet,
NLA_ALIGN(userdata->nla_len));
}
- ofpbuf_set_data(&upcall->packet,
- ofpbuf_put(buf, ofpbuf_data(packet),
ofpbuf_size(packet)));
- ofpbuf_set_size(&upcall->packet, ofpbuf_size(packet));
+ upcall->packet = *packet;
seq_change(q->seq);
error = 0;
} else {
dp_netdev_count_packet(dp, DP_STAT_LOST);
+ ofpbuf_delete(packet);
error = ENOBUFS;
}
ovs_mutex_unlock(&q->mutex);
@@ -2120,19 +2117,17 @@ dp_execute_cb(void *aux_, struct ofpbuf *packet,
break;
case OVS_ACTION_ATTR_USERSPACE: {
+ struct ofpbuf *userspace_packet;
const struct nlattr *userdata;
userdata = nl_attr_find_nested(a, OVS_USERSPACE_ATTR_USERDATA);
+ userspace_packet = may_steal ? packet : ofpbuf_clone(packet);
- dp_netdev_output_userspace(aux->dp, packet,
+ dp_netdev_output_userspace(aux->dp, userspace_packet,
miniflow_hash_5tuple(aux->key, 0)
% aux->dp->n_handlers,
DPIF_UC_ACTION, aux->key,
userdata);
-
- if (may_steal) {
- ofpbuf_delete(packet);
- }
break;
}
--
1.7.9.5
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