diff options
| -rw-r--r-- | drivers/net/virtio_net.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6e47e653a05d..f9381e1f365f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -29,6 +29,7 @@ #include <linux/slab.h> #include <linux/cpu.h> #include <linux/average.h> +#include <net/route.h> static int napi_weight = NAPI_POLL_WEIGHT; module_param(napi_weight, int, 0444); @@ -98,6 +99,9 @@ struct receive_queue { /* RX: fragments + linear part + virtio header */ struct scatterlist sg[MAX_SKB_FRAGS + 2]; + /* Min single buffer size for mergeable buffers case. */ + unsigned int min_buf_len; + /* Name of this receive queue: input.$index */ char name[40]; }; @@ -831,13 +835,14 @@ static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq, return err; } -static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len) +static unsigned int get_mergeable_buf_len(struct receive_queue *rq, + struct ewma_pkt_len *avg_pkt_len) { const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); unsigned int len; len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len), - GOOD_PACKET_LEN, PAGE_SIZE - hdr_len); + rq->min_buf_len - hdr_len, PAGE_SIZE - hdr_len); return ALIGN(len, L1_CACHE_BYTES); } @@ -851,7 +856,7 @@ static int add_recvbuf_mergeable(struct virtnet_info *vi, int err; unsigned int len, hole; - len = get_mergeable_buf_len(&rq->mrg_avg_pkt_len); + len = get_mergeable_buf_len(rq, &rq->mrg_avg_pkt_len); if (unlikely(!skb_page_frag_refill(len + headroom, alloc_frag, gfp))) return -ENOMEM; @@ -2023,6 +2028,21 @@ static void virtnet_del_vqs(struct virtnet_info *vi) virtnet_free_queues(vi); } +/* How large should a single buffer be so a queue full of these can fit at + * least one full packet? + * Logic below assumes the mergeable buffer header is used. + */ +static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqueue *vq) +{ + const unsigned int hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); + unsigned int rq_size = virtqueue_get_vring_size(vq); + unsigned int packet_len = vi->big_packets ? IP_MAX_MTU : vi->dev->max_mtu; + unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len; + unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size); + + return max(min_buf_len, hdr_len); +} + static int virtnet_find_vqs(struct virtnet_info *vi) { vq_callback_t **callbacks; @@ -2088,6 +2108,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi) for (i = 0; i < vi->max_queue_pairs; i++) { vi->rq[i].vq = vqs[rxq2vq(i)]; + vi->rq[i].min_buf_len = mergeable_min_buf_len(vi, vi->rq[i].vq); vi->sq[i].vq = vqs[txq2vq(i)]; } @@ -2174,7 +2195,8 @@ static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue, BUG_ON(queue_index >= vi->max_queue_pairs); avg = &vi->rq[queue_index].mrg_avg_pkt_len; - return sprintf(buf, "%u\n", get_mergeable_buf_len(avg)); + return sprintf(buf, "%u\n", + get_mergeable_buf_len(&vi->rq[queue_index], avg)); } static struct rx_queue_attribute mergeable_rx_buffer_size_attribute = |