From 9e2feace1acd38d7a3b1275f7f9f8a397d09040e Mon Sep 17 00:00:00 2001 From: Auke Kok Date: Fri, 14 Apr 2006 19:05:18 -0700 Subject: [PATCH] e1000: Buffer optimizations for small MTU Remove multi-descriptor support from legacy recieve path Add memory usage efficiency by using more correct size descriptors for small MTU sizes and optimize using LPE for <= 1522 byte frame sizes An extra performance fix that effected our TCP window size growth as a receiver. Set our initial buffer to be 128 bytes instead of 256 to prevent over-socket charge when truesize is computed in the stack. old way: truesize = 256 + l1 = 256 + 1460 = 1716 new way: truesize = 128 + l1 = 128 + 1460 = 1588 The magic value that we can't cross is 1648. Signed-off-by: Jesse Brandeburg Signed-off-by: Auke Kok Signed-off-by: John Ronciak --- drivers/net/e1000/e1000.h | 2 + drivers/net/e1000/e1000_main.c | 87 +++++++++++++++++++--------------- 2 files changed, 52 insertions(+), 37 deletions(-) diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h index 764808f370..2dfabdb29e 100644 --- a/drivers/net/e1000/e1000.h +++ b/drivers/net/e1000/e1000.h @@ -114,6 +114,8 @@ struct e1000_adapter; /* Supported Rx Buffer Sizes */ #define E1000_RXBUFFER_128 128 /* Used for packet split */ #define E1000_RXBUFFER_256 256 /* Used for packet split */ +#define E1000_RXBUFFER_512 512 +#define E1000_RXBUFFER_1024 1024 #define E1000_RXBUFFER_2048 2048 #define E1000_RXBUFFER_4096 4096 #define E1000_RXBUFFER_8192 8192 diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c index 6d7ba0bb23..f604a1dea3 100644 --- a/drivers/net/e1000/e1000_main.c +++ b/drivers/net/e1000/e1000_main.c @@ -972,8 +972,8 @@ e1000_sw_init(struct e1000_adapter *adapter) pci_read_config_word(pdev, PCI_COMMAND, &hw->pci_cmd_word); - adapter->rx_buffer_len = E1000_RXBUFFER_2048; - adapter->rx_ps_bsize0 = E1000_RXBUFFER_256; + adapter->rx_buffer_len = MAXIMUM_ETHERNET_FRAME_SIZE; + adapter->rx_ps_bsize0 = E1000_RXBUFFER_128; hw->max_frame_size = netdev->mtu + ENET_HEADER_SIZE + ETHERNET_FCS_SIZE; hw->min_frame_size = MINIMUM_ETHERNET_FRAME_SIZE; @@ -1599,14 +1599,21 @@ e1000_setup_rctl(struct e1000_adapter *adapter) rctl |= E1000_RCTL_LPE; /* Setup buffer sizes */ - if (adapter->hw.mac_type >= e1000_82571) { - /* We can now specify buffers in 1K increments. - * BSIZE and BSEX are ignored in this case. */ - rctl |= adapter->rx_buffer_len << 0x11; - } else { - rctl &= ~E1000_RCTL_SZ_4096; - rctl |= E1000_RCTL_BSEX; - switch (adapter->rx_buffer_len) { + rctl &= ~E1000_RCTL_SZ_4096; + rctl |= E1000_RCTL_BSEX; + switch (adapter->rx_buffer_len) { + case E1000_RXBUFFER_256: + rctl |= E1000_RCTL_SZ_256; + rctl &= ~E1000_RCTL_BSEX; + break; + case E1000_RXBUFFER_512: + rctl |= E1000_RCTL_SZ_512; + rctl &= ~E1000_RCTL_BSEX; + break; + case E1000_RXBUFFER_1024: + rctl |= E1000_RCTL_SZ_1024; + rctl &= ~E1000_RCTL_BSEX; + break; case E1000_RXBUFFER_2048: default: rctl |= E1000_RCTL_SZ_2048; @@ -1621,7 +1628,6 @@ e1000_setup_rctl(struct e1000_adapter *adapter) case E1000_RXBUFFER_16384: rctl |= E1000_RCTL_SZ_16384; break; - } } #ifndef CONFIG_E1000_DISABLE_PACKET_SPLIT @@ -2982,8 +2988,7 @@ e1000_change_mtu(struct net_device *netdev, int new_mtu) /* Adapter-specific max frame size limits. */ switch (adapter->hw.mac_type) { - case e1000_82542_rev2_0: - case e1000_82542_rev2_1: + case e1000_undefined ... e1000_82542_rev2_1: if (max_frame > MAXIMUM_ETHERNET_FRAME_SIZE) { DPRINTK(PROBE, ERR, "Jumbo Frames not supported.\n"); return -EINVAL; @@ -3017,27 +3022,32 @@ e1000_change_mtu(struct net_device *netdev, int new_mtu) break; } - - if (adapter->hw.mac_type > e1000_82547_rev_2) { - adapter->rx_buffer_len = max_frame; - E1000_ROUNDUP(adapter->rx_buffer_len, 1024); - } else { - if(unlikely((adapter->hw.mac_type < e1000_82543) && - (max_frame > MAXIMUM_ETHERNET_FRAME_SIZE))) { - DPRINTK(PROBE, ERR, "Jumbo Frames not supported " - "on 82542\n"); - return -EINVAL; - } else { - if(max_frame <= E1000_RXBUFFER_2048) - adapter->rx_buffer_len = E1000_RXBUFFER_2048; - else if(max_frame <= E1000_RXBUFFER_4096) - adapter->rx_buffer_len = E1000_RXBUFFER_4096; - else if(max_frame <= E1000_RXBUFFER_8192) - adapter->rx_buffer_len = E1000_RXBUFFER_8192; - else if(max_frame <= E1000_RXBUFFER_16384) - adapter->rx_buffer_len = E1000_RXBUFFER_16384; - } - } + /* NOTE: dev_alloc_skb reserves 16 bytes, and typically NET_IP_ALIGN + * means we reserve 2 more, this pushes us to allocate from the next + * larger slab size + * i.e. RXBUFFER_2048 --> size-4096 slab */ + + if (max_frame <= E1000_RXBUFFER_256) + adapter->rx_buffer_len = E1000_RXBUFFER_256; + else if (max_frame <= E1000_RXBUFFER_512) + adapter->rx_buffer_len = E1000_RXBUFFER_512; + else if (max_frame <= E1000_RXBUFFER_1024) + adapter->rx_buffer_len = E1000_RXBUFFER_1024; + else if (max_frame <= E1000_RXBUFFER_2048) + adapter->rx_buffer_len = E1000_RXBUFFER_2048; + else if (max_frame <= E1000_RXBUFFER_4096) + adapter->rx_buffer_len = E1000_RXBUFFER_4096; + else if (max_frame <= E1000_RXBUFFER_8192) + adapter->rx_buffer_len = E1000_RXBUFFER_8192; + else if (max_frame <= E1000_RXBUFFER_16384) + adapter->rx_buffer_len = E1000_RXBUFFER_16384; + + /* adjust allocation if LPE protects us, and we aren't using SBP */ +#define MAXIMUM_ETHERNET_VLAN_SIZE 1522 + if (!adapter->hw.tbi_compatibility_on && + ((max_frame == MAXIMUM_ETHERNET_FRAME_SIZE) || + (max_frame == MAXIMUM_ETHERNET_VLAN_SIZE))) + adapter->rx_buffer_len = MAXIMUM_ETHERNET_VLAN_SIZE; netdev->mtu = new_mtu; @@ -3568,10 +3578,12 @@ e1000_clean_rx_irq(struct e1000_adapter *adapter, flags); length--; } else { - dev_kfree_skb_irq(skb); + /* recycle */ + buffer_info->skb = skb; goto next_desc; } - } + } else + skb_put(skb, length); /* code added for copybreak, this should improve * performance for small packets with large amounts @@ -3676,6 +3688,7 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter, i = rx_ring->next_to_clean; rx_desc = E1000_RX_DESC_PS(*rx_ring, i); staterr = le32_to_cpu(rx_desc->wb.middle.status_error); + buffer_info = &rx_ring->buffer_info[i]; while (staterr & E1000_RXD_STAT_DD) { buffer_info = &rx_ring->buffer_info[i]; @@ -3736,7 +3749,7 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter, /* page alloc/put takes too long and effects small packet * throughput, so unsplit small packets and save the alloc/put*/ - if (l1 && ((length + l1) < E1000_CB_LENGTH)) { + if (l1 && ((length + l1) <= adapter->rx_ps_bsize0)) { u8 *vaddr; /* there is no documentation about how to call * kmap_atomic, so we can't hold the mapping -- 2.39.5