[ovs-dev] [RFC PATCH V4 8/9] netdev-dpdk: copy large packet to multi-seg. mbufs
Mark Kavanagh
mark.b.kavanagh at intel.com
Fri Dec 8 12:01:57 UTC 2017
From: Michael Qiu <qiudayu at chinac.com>
Currently, packets are only copied to a single segment in
the function dpdk_do_tx_copy(). This could be an issue in
the case of jumbo frames, particularly when multi-segment
mbufs are involved.
This patch calculates the number of segments needed by a
packet and copies the data to each segment.
Co-authored-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
Signed-off-by: Michael Qiu <qiudayu at chinac.com>
Signed-off-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
---
lib/netdev-dpdk.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 52 insertions(+), 4 deletions(-)
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 8a81690..f83bb9e 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -1830,8 +1830,10 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct dp_packet_batch *batch)
#endif
struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
struct rte_mbuf *pkts[PKT_ARRAY_SIZE];
+ struct rte_mbuf *temp, *head = NULL;
uint32_t cnt = batch_cnt;
uint32_t dropped = 0;
+ uint32_t i, j, nb_segs;
if (dev->type != DPDK_DEV_VHOST) {
/* Check if QoS has been configured for this netdev. */
@@ -1844,9 +1846,10 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct dp_packet_batch *batch)
uint32_t txcnt = 0;
- for (uint32_t i = 0; i < cnt; i++) {
+ for (i = 0; i < cnt; i++) {
struct dp_packet *packet = batch->packets[i];
uint32_t size = dp_packet_size(packet);
+ uint16_t max_data_len, data_len;
if (OVS_UNLIKELY(size > dev->max_packet_len)) {
VLOG_WARN_RL(&rl, "Too big size %u max_packet_len %d",
@@ -1856,15 +1859,60 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct dp_packet_batch *batch)
continue;
}
- pkts[txcnt] = rte_pktmbuf_alloc(dev->mp);
+ temp = pkts[txcnt] = rte_pktmbuf_alloc(dev->mp);
if (OVS_UNLIKELY(!pkts[txcnt])) {
dropped += cnt - i;
break;
}
+ /* All new allocated mbuf's max data len is the same */
+ max_data_len = temp->buf_len - temp->data_off;
+
+ /* Calculate # of output mbufs. */
+ nb_segs = size / max_data_len;
+ if (size % max_data_len) {
+ nb_segs = nb_segs + 1;
+ }
+
+ /* Allocate additional mbufs when multiple output mbufs required. */
+ for (j = 1; j < nb_segs; j++) {
+ temp->next = rte_pktmbuf_alloc(dev->mp);
+ if (!temp->next) {
+ rte_pktmbuf_free(pkts[txcnt]);
+ pkts[txcnt] = NULL;
+ break;
+ }
+ temp = temp->next;
+ }
/* We have to do a copy for now */
- memcpy(rte_pktmbuf_mtod(pkts[txcnt], void *),
- dp_packet_data(packet), size);
+ rte_pktmbuf_pkt_len(pkts[txcnt]) = size;
+ temp = pkts[txcnt];
+
+ data_len = size < max_data_len ? size: max_data_len;
+ if (packet->source == DPBUF_DPDK) {
+ head = &(packet->mbuf);
+ while (temp && head && size > 0) {
+ rte_memcpy(rte_pktmbuf_mtod(temp, void *),
+ dp_packet_data((struct dp_packet *)head), data_len);
+ rte_pktmbuf_data_len(temp) = data_len;
+ head = head->next;
+ size = size - data_len;
+ data_len = size < max_data_len ? size: max_data_len;
+ temp = temp->next;
+ }
+ } else {
+ int offset = 0;
+ while (temp && size > 0) {
+ memcpy(rte_pktmbuf_mtod(temp, void *),
+ dp_packet_at(packet, offset, data_len), data_len);
+ rte_pktmbuf_data_len(temp) = data_len;
+ temp = temp->next;
+ size = size - data_len;
+ offset += data_len;
+ data_len = size < max_data_len ? size: max_data_len;
+ }
+ }
+
dp_packet_set_size((struct dp_packet *)pkts[txcnt], size);
pkts[txcnt]->nb_segs = packet->mbuf.nb_segs;
pkts[txcnt]->ol_flags = packet->mbuf.ol_flags;
--
1.9.3
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