Sorry, forgot to Cc Michael and the virt list - patch reproduced below
in full.
johannes
>From 22500fbcf722748fe3471b2e4c6156db47aade15 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg at intel.com>
Date: Wed, 19 Aug 2015 09:25:18 +0200
Subject: [PATCH] virtio_net: use DECLARE_EWMA
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 at intel.com>
---
drivers/net/Kconfig | 1 -
drivers/net/virtio_net.c | 22 +++++++++++-----------
2 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index e58468b02987..f50373645ab4 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -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.
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 546b669fbfdd..9b950f2db836 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -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;
