From: Auke Kok Date: Thu, 25 May 2006 20:24:17 +0000 (-0700) Subject: ixgb: add performance enhancements to the buffer_info struct X-Git-Tag: v2.6.18-rc1~1115^2~54 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1dfdd7df21309e57867962020a5ccb83d00e5432;p=linux-2.6 ixgb: add performance enhancements to the buffer_info struct o modify the rx refill logic and tail bump o add counter for failures Signed-off-by: Jesse Brandeburg Signed-off-by: Auke Kok Signed-off-by: John Ronciak --- diff --git a/drivers/net/ixgb/ixgb.h b/drivers/net/ixgb/ixgb.h index b9c37fdc84..bdbaf5accc 100644 --- a/drivers/net/ixgb/ixgb.h +++ b/drivers/net/ixgb/ixgb.h @@ -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 diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c index 0905a82409..27034b3ba8 100644 --- a/drivers/net/ixgb/ixgb_main.c +++ b/drivers/net/ixgb/ixgb_main.c @@ -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, - PCI_DMA_TODEVICE); - buffer_info->dma = 0; - } - if(buffer_info->skb) { + + if (buffer_info->dma) + pci_unmap_page(pdev, buffer_info->dma, buffer_info->length, + PCI_DMA_TODEVICE); + + if (buffer_info->skb) dev_kfree_skb_any(buffer_info->skb); - buffer_info->skb = NULL; - } + + 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)) { + 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, - skb->data, - adapter->rx_buffer_len, - PCI_DMA_FROMDEVICE); +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]; } - rx_ring->next_to_use = 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); + } } /**