diff options
Diffstat (limited to 'drivers/net/virtio/virtio_rxtx.c')
| -rw-r--r-- | drivers/net/virtio/virtio_rxtx.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c index 22d97a4e..a33ef1a8 100644 --- a/drivers/net/virtio/virtio_rxtx.c +++ b/drivers/net/virtio/virtio_rxtx.c @@ -258,6 +258,12 @@ tx_offload_enabled(struct virtio_hw *hw) vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6); } +/* avoid write operation when necessary, to lessen cache issues */ +#define ASSIGN_UNLESS_EQUAL(var, val) do { \ + if ((var) != (val)) \ + (var) = (val); \ +} while (0) + static inline void virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie, uint16_t needed, int use_indirect, int can_push) @@ -286,8 +292,14 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie, hdr = (struct virtio_net_hdr *) rte_pktmbuf_prepend(cookie, head_size); /* if offload disabled, it is not zeroed below, do it now */ - if (offload == 0) - memset(hdr, 0, head_size); + if (offload == 0) { + ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0); + ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0); + ASSIGN_UNLESS_EQUAL(hdr->flags, 0); + ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0); + ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0); + ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0); + } } else if (use_indirect) { /* setup tx ring slot to point to indirect * descriptor list stored in reserved region. @@ -337,9 +349,9 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie, break; default: - hdr->csum_start = 0; - hdr->csum_offset = 0; - hdr->flags = 0; + ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0); + ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0); + ASSIGN_UNLESS_EQUAL(hdr->flags, 0); break; } @@ -355,9 +367,9 @@ virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie, cookie->l3_len + cookie->l4_len; } else { - hdr->gso_type = 0; - hdr->gso_size = 0; - hdr->hdr_len = 0; + ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0); + ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0); + ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0); } } |