From: Jason Wang <jasow...@redhat.com> We already have counters for sent packets and sent bytes. Use them to reduce the number of u64_stats_update_begin/end().
Take care not to bother with stats update when called speculatively. Based on a patch by Jason Wang. Cc: Rusty Russell <ru...@rustcorp.com.au> Signed-off-by: Jason Wang <jasow...@redhat.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- drivers/net/virtio_net.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8dea411..4e12023 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -233,16 +233,22 @@ static unsigned int free_old_xmit_skbs(struct netdev_queue *txq, (skb = virtqueue_get_buf(sq->vq, &len)) != NULL) { pr_debug("Sent skb %p\n", skb); - u64_stats_update_begin(&stats->tx_syncp); - stats->tx_bytes += skb->len; bytes += skb->len; - stats->tx_packets++; - u64_stats_update_end(&stats->tx_syncp); + packets++; dev_kfree_skb_any(skb); - packets++; } + /* Avoid overhead when no packets have been processed + * happens when called speculatively from start_xmit. */ + if (!packets) + return 0; + + u64_stats_update_begin(&stats->tx_syncp); + stats->tx_bytes += bytes; + stats->tx_packets += packets; + u64_stats_update_end(&stats->tx_syncp); + netdev_tx_completed_queue(txq, packets, bytes); return packets; -- MST _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization