ixgb: add performance enhancements to the buffer_info struct (1dfdd7df) · Commits · 戴 / test

drivers/net/ixgb/ixgb.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -200,6 +200,7 @@ struct ixgb_adapter {
		struct ixgb_hw hw;
		u16 msg_enable;
		struct ixgb_hw_stats stats;
		uint32_t alloc_rx_buff_failed;
		#ifdef CONFIG_PCI_MSI
		boolean_t have_msi;
		#endif

drivers/net/ixgb/ixgb_main.c

+44 −30

Original line number	Diff line number	Diff line
		@@ -929,17 +929,20 @@ ixgb_unmap_and_free_tx_resource(struct ixgb_adapter *adapter,
		struct ixgb_buffer *buffer_info)
		{
		struct pci_dev *pdev = adapter->pdev;
		if(buffer_info->dma) {
		pci_unmap_page(pdev,
		buffer_info->dma,
		buffer_info->length,

		if (buffer_info->dma)
		pci_unmap_page(pdev, buffer_info->dma, buffer_info->length,
		PCI_DMA_TODEVICE);
		buffer_info->dma = 0;
		}
		if(buffer_info->skb) {

		if (buffer_info->skb)
		dev_kfree_skb_any(buffer_info->skb);

		buffer_info->skb = NULL;
		}
		buffer_info->dma = 0;
		buffer_info->time_stamp = 0;
		/* these fields must always be initialized in tx
		* buffer_info->length = 0;
		* buffer_info->next_to_watch = 0; */
		}

		/**
		@@ -1314,6 +1317,7 @@ ixgb_tx_map(struct ixgb_adapter adapter, struct sk_buff skb,
		size,
		PCI_DMA_TODEVICE);
		buffer_info->time_stamp = jiffies;
		buffer_info->next_to_watch = 0;

		len -= size;
		offset += size;
		@@ -1345,6 +1349,7 @@ ixgb_tx_map(struct ixgb_adapter adapter, struct sk_buff skb,
		size,
		PCI_DMA_TODEVICE);
		buffer_info->time_stamp = jiffies;
		buffer_info->next_to_watch = 0;

		len -= size;
		offset += size;
		@@ -1940,6 +1945,7 @@ ixgb_clean_rx_irq(struct ixgb_adapter *adapter)
		#endif
		status = rx_desc->status;
		skb = buffer_info->skb;
		buffer_info->skb = NULL;

		prefetch(skb->data);

		@@ -2013,7 +2019,6 @@ ixgb_clean_rx_irq(struct ixgb_adapter *adapter)
		rxdesc_done:
		/* clean up descriptor, might be written over by hw */
		rx_desc->status = 0;
		buffer_info->skb = NULL;

		/* use prefetched values */
		rx_desc = next_rxd;
		@@ -2053,12 +2058,18 @@ ixgb_alloc_rx_buffers(struct ixgb_adapter *adapter)

		/* leave three descriptors unused */
		while(--cleancount > 2) {
		rx_desc = IXGB_RX_DESC(*rx_ring, i);

		skb = dev_alloc_skb(adapter->rx_buffer_len + NET_IP_ALIGN);
		/* recycle! its good for you */
		if (!(skb = buffer_info->skb))
		skb = dev_alloc_skb(adapter->rx_buffer_len
		+ NET_IP_ALIGN);
		else {
		skb_trim(skb, 0);
		goto map_skb;
		}

		if (unlikely(!skb)) {
		/* Better luck next round */
		adapter->alloc_rx_buff_failed++;
		break;
		}

		@@ -2072,33 +2083,36 @@ ixgb_alloc_rx_buffers(struct ixgb_adapter *adapter)

		buffer_info->skb = skb;
		buffer_info->length = adapter->rx_buffer_len;
		buffer_info->dma =
		pci_map_single(pdev,
		map_skb:
		buffer_info->dma = pci_map_single(pdev,
		skb->data,
		adapter->rx_buffer_len,
		PCI_DMA_FROMDEVICE);

		rx_desc = IXGB_RX_DESC(*rx_ring, i);
		rx_desc->buff_addr = cpu_to_le64(buffer_info->dma);
		/* guarantee DD bit not set now before h/w gets descriptor
		* this is the rest of the workaround for h/w double
		* writeback. */
		rx_desc->status = 0;

		if((i & ~(num_group_tail_writes- 1)) == i) {
		/* Force memory writes to complete before letting h/w
		* know there are new descriptors to fetch. (Only
		* applicable for weak-ordered memory model archs,
		* such as IA-64). */
		wmb();

		IXGB_WRITE_REG(&adapter->hw, RDT, i);
		}

		if(++i == rx_ring->count) i = 0;
		buffer_info = &rx_ring->buffer_info[i];
		}

		if (likely(rx_ring->next_to_use != i)) {
		rx_ring->next_to_use = i;
		if (unlikely(i-- == 0))
		i = (rx_ring->count - 1);

		/* Force memory writes to complete before letting h/w
		* know there are new descriptors to fetch. (Only
		* applicable for weak-ordered memory model archs, such
		* as IA-64). */
		wmb();
		IXGB_WRITE_REG(&adapter->hw, RDT, i);
		}
		}

		/**

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