From 2bcb4b0f111053d0e8fb4366f0708395d997e93a Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Wed, 1 Oct 2008 02:33:57 -0700 Subject: [PATCH] mv643xx_eth: hook up skb recycling This gives a nice increase in the maximum loss-free packet forwarding rate in routing workloads. Signed-off-by: Lennert Buytenhek Signed-off-by: David S. Miller --- drivers/net/mv643xx_eth.c | 66 ++++++++++++++++++++++++++------------- 1 file changed, 45 insertions(+), 21 deletions(-) diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c index 55aa8ba7e0f2..372811ade9f5 100644 --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -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))