From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santiago Leon Subject: [patch 05/21] ibmveth: Add rx_copybreak Date: Fri, 03 Sep 2010 23:28:25 -0500 Message-ID: <20100904042825.2655.81137.sendpatchset@jupiter1-ltc-lp2.austin.ibm.com> References: <20100904042758.2655.8093.sendpatchset@jupiter1-ltc-lp2.austin.ibm.com> Cc: brking@linux.vnet.ibm.com, Santiago Leon , anton@samba.org To: netdev@vger.kernel.org Return-path: Received: from e33.co.us.ibm.com ([32.97.110.151]:43740 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937Ab0IDE2y (ORCPT ); Sat, 4 Sep 2010 00:28:54 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e33.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id o844Nu7x001871 for ; Fri, 3 Sep 2010 22:23:56 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o844Srgx094480 for ; Fri, 3 Sep 2010 22:28:53 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o844SrPQ032288 for ; Fri, 3 Sep 2010 22:28:53 -0600 In-Reply-To: <20100904042758.2655.8093.sendpatchset@jupiter1-ltc-lp2.austin.ibm.com> Sender: netdev-owner@vger.kernel.org List-ID: For small packets, create a new skb and copy the packet into it so we avoid tearing down and creating a TCE entry. Signed-off-by: Anton Blanchard Signed-off-by: Santiago Leon --- Index: net-next-2.6/drivers/net/ibmveth.c =================================================================== --- net-next-2.6.orig//drivers/net/ibmveth.c 2010-09-03 22:18:45.000000000 -0500 +++ net-next-2.6/drivers/net/ibmveth.c 2010-09-03 22:18:46.000000000 -0500 @@ -122,6 +122,11 @@ module_param(tx_copybreak, uint, 0644); MODULE_PARM_DESC(tx_copybreak, "Maximum size of packet that is copied to a new buffer on transmit"); +static unsigned int rx_copybreak __read_mostly = 128; +module_param(rx_copybreak, uint, 0644); +MODULE_PARM_DESC(rx_copybreak, + "Maximum size of packet that is copied to a new buffer on receive"); + struct ibmveth_stat { char name[ETH_GSTRING_LEN]; int offset; @@ -1002,8 +1007,6 @@ static int ibmveth_poll(struct napi_stru restart_poll: do { - struct sk_buff *skb; - if (!ibmveth_rxq_pending_buffer(adapter)) break; @@ -1014,20 +1017,34 @@ static int ibmveth_poll(struct napi_stru ibmveth_debug_printk("recycling invalid buffer\n"); ibmveth_rxq_recycle_buffer(adapter); } else { + struct sk_buff *skb, *new_skb; int length = ibmveth_rxq_frame_length(adapter); int offset = ibmveth_rxq_frame_offset(adapter); int csum_good = ibmveth_rxq_csum_good(adapter); skb = ibmveth_rxq_get_buffer(adapter); - if (csum_good) - skb->ip_summed = CHECKSUM_UNNECESSARY; - ibmveth_rxq_harvest_buffer(adapter); + new_skb = NULL; + if (length < rx_copybreak) + new_skb = netdev_alloc_skb(netdev, length); + + if (new_skb) { + skb_copy_to_linear_data(new_skb, + skb->data + offset, + length); + skb = new_skb; + ibmveth_rxq_recycle_buffer(adapter); + } else { + ibmveth_rxq_harvest_buffer(adapter); + skb_reserve(skb, offset); + } - skb_reserve(skb, offset); skb_put(skb, length); skb->protocol = eth_type_trans(skb, netdev); + if (csum_good) + skb->ip_summed = CHECKSUM_UNNECESSARY; + netif_receive_skb(skb); /* send it up */ netdev->stats.rx_packets++;