From: Benjamin LaHaise Date: Tue, 4 Aug 2009 10:21:57 +0000 (+0000) Subject: vxge: prefetch skb->data X-Git-Tag: v2.6.32-rc1~703^2~463 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=ea11bbe0c94b045fdefc05476b69a2eef999a9c4;p=linux-2.6-block.git vxge: prefetch skb->data This patch implements prefetching of skb->data from a copy of the pointer in the descriptor (which is already in the L1 cache at this point). This improves netperf rx performance (netperf -L 0,0 -c -H 192.168.254.2 -- -M 131072 -m 131072) by 4.9% on a P4 Xeon host. Signed-off-by: Benjamin LaHaise Signed-off-by: Sreenivasa Honnur Signed-off-by: Ramkrishna Vepa Signed-off-by: David S. Miller --- diff --git a/drivers/net/vxge/vxge-main.c b/drivers/net/vxge/vxge-main.c index e93651c19f59..094d15548a2b 100644 --- a/drivers/net/vxge/vxge-main.c +++ b/drivers/net/vxge/vxge-main.c @@ -286,6 +286,7 @@ vxge_rx_alloc(void *dtrh, struct vxge_ring *ring, const int skb_size) skb_reserve(skb, VXGE_HW_HEADER_ETHERNET_II_802_3_ALIGN); rx_priv->skb = skb; + rx_priv->skb_data = NULL; rx_priv->data_size = skb_size; vxge_debug_entryexit(VXGE_TRACE, "%s: %s:%d Exiting...", ring->ndev->name, __func__, __LINE__); @@ -305,7 +306,8 @@ static int vxge_rx_map(void *dtrh, struct vxge_ring *ring) ring->ndev->name, __func__, __LINE__); rx_priv = vxge_hw_ring_rxd_private_get(dtrh); - dma_addr = pci_map_single(ring->pdev, rx_priv->skb->data, + rx_priv->skb_data = rx_priv->skb->data; + dma_addr = pci_map_single(ring->pdev, rx_priv->skb_data, rx_priv->data_size, PCI_DMA_FROMDEVICE); if (dma_addr == 0) { @@ -450,6 +452,7 @@ vxge_rx_1b_compl(struct __vxge_hw_ring *ringh, void *dtr, skb = rx_priv->skb; data_size = rx_priv->data_size; data_dma = rx_priv->data_dma; + prefetch(rx_priv->skb_data); vxge_debug_rx(VXGE_TRACE, "%s: %s:%d skb = 0x%p", @@ -1056,6 +1059,7 @@ vxge_rx_term(void *dtrh, enum vxge_hw_rxd_state state, void *userdata) rx_priv->data_size, PCI_DMA_FROMDEVICE); dev_kfree_skb(rx_priv->skb); + rx_priv->skb_data = NULL; vxge_debug_entryexit(VXGE_TRACE, "%s: %s:%d Exiting...", diff --git a/drivers/net/vxge/vxge-main.h b/drivers/net/vxge/vxge-main.h index 8b3989bc707f..9c36b3a9a63d 100644 --- a/drivers/net/vxge/vxge-main.h +++ b/drivers/net/vxge/vxge-main.h @@ -378,6 +378,7 @@ struct vxgedev { struct vxge_rx_priv { struct sk_buff *skb; + unsigned char *skb_data; dma_addr_t data_dma; dma_addr_t data_size; };