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virtio_net: use DECLARE_EWMA

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Instead of using the out-of-line EWMA calculation, use DECLARE_EWMA()
to create static inlines. On x86/64 this results in no change in code
size for me, but reduces the struct receive_queue size by the two
unsigned long values that store the parameters.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Johannes Berg 2015-08-19 09:48:40 +02:00 committed by David S. Miller
parent 0f8f27de19
commit 5377d75823
2 changed files with 11 additions and 12 deletions
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1
drivers/net/Kconfig
View File

@ -282,7 +282,6 @@ config VETH
config VIRTIO_NET config VIRTIO_NET
tristate "Virtio network driver" tristate "Virtio network driver"
depends on VIRTIO depends on VIRTIO
select AVERAGE
---help--- ---help---
This is the virtual network driver for virtio. It can be used with This is the virtual network driver for virtio. It can be used with
lguest or QEMU based VMMs (like KVM or Xen). Say Y or M. lguest or QEMU based VMMs (like KVM or Xen). Say Y or M.

22
drivers/net/virtio_net.c
View File

@ -40,12 +40,12 @@ module_param(gso, bool, 0444);
#define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN) #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
#define GOOD_COPY_LEN 128 #define GOOD_COPY_LEN 128
/* Weight used for the RX packet size EWMA. The average packet size is used to /* RX packet size EWMA. The average packet size is used to determine the packet
* determine the packet buffer size when refilling RX rings. As the entire RX * buffer size when refilling RX rings. As the entire RX ring may be refilled
* ring may be refilled at once, the weight is chosen so that the EWMA will be * at once, the weight is chosen so that the EWMA will be insensitive to short-
* insensitive to short-term, transient changes in packet size. * term, transient changes in packet size.
*/ */
#define RECEIVE_AVG_WEIGHT 64 DECLARE_EWMA(pkt_len, 1, 64)
/* Minimum alignment for mergeable packet buffers. */ /* Minimum alignment for mergeable packet buffers. */
#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256) #define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
@ -85,7 +85,7 @@ struct receive_queue {
struct page *pages; struct page *pages;
/* Average packet length for mergeable receive buffers. */ /* Average packet length for mergeable receive buffers. */
struct ewma mrg_avg_pkt_len; struct ewma_pkt_len mrg_avg_pkt_len;
/* Page frag for packet buffer allocation. */ /* Page frag for packet buffer allocation. */
struct page_frag alloc_frag; struct page_frag alloc_frag;
@ -407,7 +407,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
} }
} }
ewma_add(&rq->mrg_avg_pkt_len, head_skb->len); ewma_pkt_len_add(&rq->mrg_avg_pkt_len, head_skb->len);
return head_skb; return head_skb;
err_skb: err_skb:
@ -600,12 +600,12 @@ static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
return err; return err;
} }
static unsigned int get_mergeable_buf_len(struct ewma *avg_pkt_len) static unsigned int get_mergeable_buf_len(struct ewma_pkt_len *avg_pkt_len)
{ {
const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
unsigned int len; unsigned int len;
len = hdr_len + clamp_t(unsigned int, ewma_read(avg_pkt_len), len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
GOOD_PACKET_LEN, PAGE_SIZE - hdr_len); GOOD_PACKET_LEN, PAGE_SIZE - hdr_len);
return ALIGN(len, MERGEABLE_BUFFER_ALIGN); return ALIGN(len, MERGEABLE_BUFFER_ALIGN);
} }
@ -1615,7 +1615,7 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
napi_hash_add(&vi->rq[i].napi); napi_hash_add(&vi->rq[i].napi);
sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg)); sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
ewma_init(&vi->rq[i].mrg_avg_pkt_len, 1, RECEIVE_AVG_WEIGHT); ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg)); sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
} }
@ -1658,7 +1658,7 @@ static ssize_t mergeable_rx_buffer_size_show(struct netdev_rx_queue *queue,
{ {
struct virtnet_info *vi = netdev_priv(queue->dev); struct virtnet_info *vi = netdev_priv(queue->dev);
unsigned int queue_index = get_netdev_rx_queue_index(queue); unsigned int queue_index = get_netdev_rx_queue_index(queue);
struct ewma *avg; struct ewma_pkt_len *avg;
BUG_ON(queue_index >= vi->max_queue_pairs); BUG_ON(queue_index >= vi->max_queue_pairs);
avg = &vi->rq[queue_index].mrg_avg_pkt_len; avg = &vi->rq[queue_index].mrg_avg_pkt_len;