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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
tristate "Virtio network driver"
depends on VIRTIO
select AVERAGE
---help---
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.

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_COPY_LEN 128
/* Weight used for the RX packet size EWMA. The average packet size is used to
* determine the packet buffer size when refilling RX rings. As the entire RX
* ring may be refilled at once, the weight is chosen so that the EWMA will be
* insensitive to short-term, transient changes in packet size.
/* RX packet size EWMA. The average packet size is used to determine the packet
* buffer size when refilling RX rings. As the entire RX ring may be refilled
* at once, the weight is chosen so that the EWMA will be insensitive to short-
* term, transient changes in packet size.
*/
#define RECEIVE_AVG_WEIGHT 64
DECLARE_EWMA(pkt_len, 1, 64)
/* Minimum alignment for mergeable packet buffers. */
#define MERGEABLE_BUFFER_ALIGN max(L1_CACHE_BYTES, 256)
@ -85,7 +85,7 @@ struct receive_queue {
struct page *pages;
/* 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. */
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;
err_skb:
@ -600,12 +600,12 @@ static int add_recvbuf_big(struct virtnet_info *vi, struct receive_queue *rq,
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);
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);
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);
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));
}
@ -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);
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);
avg = &vi->rq[queue_index].mrg_avg_pkt_len;