Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261755AbVCGWx0 (ORCPT ); Mon, 7 Mar 2005 17:53:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261770AbVCGWwz (ORCPT ); Mon, 7 Mar 2005 17:52:55 -0500 Received: from 209-204-138-32.dsl.static.sonic.net ([209.204.138.32]:22737 "EHLO graphe.net") by vger.kernel.org with ESMTP id S261755AbVCGV0m (ORCPT ); Mon, 7 Mar 2005 16:26:42 -0500 Date: Mon, 7 Mar 2005 13:26:35 -0800 (PST) From: Christoph Lameter To: akpm@osdl.org cc: linux-kernel@vger.kernel.org, shai@scalex86.org Subject: [PATCH] remove last_rx update from loopback device Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Score: -5.5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1232 Lines: 28 The last_rx field in the loopback driver is updated on every xmit but is not used otherwise. Accesses to ->last_rx cause unecessary traffic on the interlink for NUMA systems which limits the performance of the loopback device. The comment given at include/linux/netdevice.h says that last_rx may be used for future network-power-down code, which is likely not relevant for the loopback device (please let me know if it is otherwise ..). Signed-off-by: Niraj Kumar Signed-off-by: Christoph Lameter Signed-off-by: Shai Fultheim --- linux-2.6.9.clean/drivers/net/loopback.c 2005-02-28 21:54:20.000000000 -0800 +++ linux-2.6.9.clean-loop/drivers/net/loopback.c 2005-03-03 22:59:34.068607608 -0800 @@ -144,8 +144,6 @@ static int loopback_xmit(struct sk_buff return 0; } - dev->last_rx = jiffies; - lb_stats = &per_cpu(loopback_stats, get_cpu()); lb_stats->rx_bytes += skb->len; lb_stats->tx_bytes += skb->len; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/