diff options
| author | Alexei Starovoitov <ast@plumgrid.com> | 2014-09-30 17:53:21 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-01 22:08:12 -0400 |
| commit | 38b2cf2982dc73d3f07fe84fec8cc4ed9f64c1c5 (patch) | |
| tree | e1eeab1caf5d330a4bb9c8eeb4543af5c38c769b /net/core | |
| parent | 775dd692bd34f9201ed2aa775a0edcba4f973f3e (diff) | |
net: pktgen: packet bursting via skb->xmit_more
This patch demonstrates the effect of delaying update of HW tailptr.
(based on earlier patch by Jesper)
burst=1 is the default. It sends one packet with xmit_more=false
burst=2 sends one packet with xmit_more=true and
2nd copy of the same packet with xmit_more=false
burst=3 sends two copies of the same packet with xmit_more=true and
3rd copy with xmit_more=false
Performance with ixgbe (usec 30):
burst=1 tx:9.2 Mpps
burst=2 tx:13.5 Mpps
burst=3 tx:14.5 Mpps full 10G line rate
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/pktgen.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 5c728aaf8d6c..443256bdcddc 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -387,6 +387,7 @@ struct pktgen_dev { u16 queue_map_min; u16 queue_map_max; __u32 skb_priority; /* skb priority field */ + unsigned int burst; /* number of duplicated packets to burst */ int node; /* Memory node */ #ifdef CONFIG_XFRM @@ -613,6 +614,9 @@ static int pktgen_if_show(struct seq_file *seq, void *v) if (pkt_dev->traffic_class) seq_printf(seq, " traffic_class: 0x%02x\n", pkt_dev->traffic_class); + if (pkt_dev->burst > 1) + seq_printf(seq, " burst: %d\n", pkt_dev->burst); + if (pkt_dev->node >= 0) seq_printf(seq, " node: %d\n", pkt_dev->node); @@ -1124,6 +1128,16 @@ static ssize_t pktgen_if_write(struct file *file, pkt_dev->dst_mac_count); return count; } + if (!strcmp(name, "burst")) { + len = num_arg(&user_buffer[i], 10, &value); + if (len < 0) + return len; + + i += len; + pkt_dev->burst = value < 1 ? 1 : value; + sprintf(pg_result, "OK: burst=%d", pkt_dev->burst); + return count; + } if (!strcmp(name, "node")) { len = num_arg(&user_buffer[i], 10, &value); if (len < 0) @@ -3297,6 +3311,7 @@ static void pktgen_wait_for_skb(struct pktgen_dev *pkt_dev) static void pktgen_xmit(struct pktgen_dev *pkt_dev) { + unsigned int burst = ACCESS_ONCE(pkt_dev->burst); struct net_device *odev = pkt_dev->odev; struct netdev_queue *txq; int ret; @@ -3347,8 +3362,10 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) pkt_dev->last_ok = 0; goto unlock; } - atomic_inc(&(pkt_dev->skb->users)); - ret = netdev_start_xmit(pkt_dev->skb, odev, txq, false); + atomic_add(burst, &pkt_dev->skb->users); + +xmit_more: + ret = netdev_start_xmit(pkt_dev->skb, odev, txq, --burst > 0); switch (ret) { case NETDEV_TX_OK: @@ -3356,6 +3373,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) pkt_dev->sofar++; pkt_dev->seq_num++; pkt_dev->tx_bytes += pkt_dev->last_pkt_size; + if (burst > 0 && !netif_xmit_frozen_or_drv_stopped(txq)) + goto xmit_more; break; case NET_XMIT_DROP: case NET_XMIT_CN: @@ -3374,6 +3393,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) atomic_dec(&(pkt_dev->skb->users)); pkt_dev->last_ok = 0; } + if (unlikely(burst)) + atomic_sub(burst, &pkt_dev->skb->users); unlock: HARD_TX_UNLOCK(odev, txq); @@ -3572,6 +3593,7 @@ static int pktgen_add_device(struct pktgen_thread *t, const char *ifname) pkt_dev->svlan_p = 0; pkt_dev->svlan_cfi = 0; pkt_dev->svlan_id = 0xffff; + pkt_dev->burst = 1; pkt_dev->node = -1; err = pktgen_setup_dev(t->net, pkt_dev, ifname); |