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mv643xx_eth: hook up skb recycling

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This gives a nice increase in the maximum loss-free packet forwarding
rate in routing workloads.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lennert Buytenhek 2008-10-01 02:33:57 -07:00 committed by David S. Miller
parent 04a4bb55bc
commit 2bcb4b0f11
1 changed files with 45 additions and 21 deletions
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66
drivers/net/mv643xx_eth.c
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@ -370,6 +370,9 @@ struct mv643xx_eth_private {
u8 work_rx_refill;
u8 work_rx_oom;
int skb_size;
struct sk_buff_head rx_recycle;
/*
* RX state.
*/
@ -566,31 +569,19 @@ static int rxq_process(struct rx_queue *rxq, int budget)
static int rxq_refill(struct rx_queue *rxq, int budget)
{
struct mv643xx_eth_private *mp = rxq_to_mp(rxq);
int skb_size;
int refilled;
/*
* Reserve 2+14 bytes for an ethernet header (the hardware
* automatically prepends 2 bytes of dummy data to each
* received packet), 16 bytes for up to four VLAN tags, and
* 4 bytes for the trailing FCS -- 36 bytes total.
*/
skb_size = rxq_to_mp(rxq)->dev->mtu + 36;
/*
* Make sure that the skb size is a multiple of 8 bytes, as
* the lower three bits of the receive descriptor's buffer
* size field are ignored by the hardware.
*/
skb_size = (skb_size + 7) & ~7;
refilled = 0;
while (refilled < budget && rxq->rx_desc_count < rxq->rx_ring_size) {
struct sk_buff *skb;
int unaligned;
int rx;
skb = dev_alloc_skb(skb_size + dma_get_cache_alignment() - 1);
skb = __skb_dequeue(&mp->rx_recycle);
if (skb == NULL)
skb = dev_alloc_skb(mp->skb_size +
dma_get_cache_alignment() - 1);
if (skb == NULL) {
mp->work_rx_oom |= 1 << rxq->index;
goto oom;
@ -608,8 +599,8 @@ static int rxq_refill(struct rx_queue *rxq, int budget)
rxq->rx_used_desc = 0;
rxq->rx_desc_area[rx].buf_ptr = dma_map_single(NULL, skb->data,
skb_size, DMA_FROM_DEVICE);
rxq->rx_desc_area[rx].buf_size = skb_size;
mp->skb_size, DMA_FROM_DEVICE);
rxq->rx_desc_area[rx].buf_size = mp->skb_size;
rxq->rx_skb[rx] = skb;
wmb();
rxq->rx_desc_area[rx].cmd_sts = BUFFER_OWNED_BY_DMA |
@ -904,8 +895,14 @@ static int txq_reclaim(struct tx_queue *txq, int budget, int force)
desc->byte_cnt, DMA_TO_DEVICE);
}
if (skb)
dev_kfree_skb(skb);
if (skb != NULL) {
if (skb_queue_len(&mp->rx_recycle) <
mp->default_rx_ring_size &&
skb_recycle_check(skb, mp->skb_size))
__skb_queue_head(&mp->rx_recycle, skb);
else
dev_kfree_skb(skb);
}
}
__netif_tx_unlock(nq);
@ -2042,6 +2039,26 @@ static void set_tx_coal(struct mv643xx_eth_private *mp, unsigned int delay)
wrl(mp, TX_FIFO_URGENT_THRESHOLD(mp->port_num), (coal & 0x3fff) << 4);
}
static void mv643xx_eth_recalc_skb_size(struct mv643xx_eth_private *mp)
{
int skb_size;
/*
* Reserve 2+14 bytes for an ethernet header (the hardware
* automatically prepends 2 bytes of dummy data to each
* received packet), 16 bytes for up to four VLAN tags, and
* 4 bytes for the trailing FCS -- 36 bytes total.
*/
skb_size = mp->dev->mtu + 36;
/*
* Make sure that the skb size is a multiple of 8 bytes, as
* the lower three bits of the receive descriptor's buffer
* size field are ignored by the hardware.
*/
mp->skb_size = (skb_size + 7) & ~7;
}
static int mv643xx_eth_open(struct net_device *dev)
{
struct mv643xx_eth_private *mp = netdev_priv(dev);
@ -2061,8 +2078,12 @@ static int mv643xx_eth_open(struct net_device *dev)
init_mac_tables(mp);
mv643xx_eth_recalc_skb_size(mp);
napi_enable(&mp->napi);
skb_queue_head_init(&mp->rx_recycle);
for (i = 0; i < mp->rxq_count; i++) {
err = rxq_init(mp, i);
if (err) {
@ -2158,6 +2179,8 @@ static int mv643xx_eth_stop(struct net_device *dev)
mv643xx_eth_get_stats(dev);
mib_counters_update(mp);
skb_queue_purge(&mp->rx_recycle);
for (i = 0; i < mp->rxq_count; i++)
rxq_deinit(mp->rxq + i);
for (i = 0; i < mp->txq_count; i++)
@ -2184,6 +2207,7 @@ static int mv643xx_eth_change_mtu(struct net_device *dev, int new_mtu)
return -EINVAL;
dev->mtu = new_mtu;
mv643xx_eth_recalc_skb_size(mp);
tx_set_rate(mp, 1000000000, 16777216);
if (!netif_running(dev))