Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 18 Nov 2001 08:54:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 18 Nov 2001 08:54:05 -0500 Received: from mail.cogenit.fr ([195.68.53.173]:27112 "EHLO cogenit.fr") by vger.kernel.org with ESMTP id ; Sun, 18 Nov 2001 08:54:03 -0500 Date: Sun, 18 Nov 2001 14:54:00 +0100 From: Francois Romieu To: linux-kernel@vger.kernel.org Subject: Re: VM tuning for Linux routers Message-ID: <20011118145400.A23181@se1.cogenit.fr> In-Reply-To: <20011117134127.A8041@se1.cogenit.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from ecki@lina.inka.de on Sat, Nov 17, 2001 at 05:42:45PM +0100 X-Organisation: Marie's fan club - II Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Bernd Eckenfels : [...] > You can increase the reserved free memory (not sure where to do this in > 2.4.x). This is important, cause network memory requests are usually within > interrupt handlers and therefore no paging can occur. You can play a bit This reserve isn't dedicated to networking alas. [...] > > However you can increase the length of the Rx/Tx rings on the 100Mb/s side > > and tune the pci latency timers (depends on the hardware fifo size). > > Increasing rx/rx rings is not a particular good idea cause it slows down > TCPs adaption to network congestion and router overload. Think about forwarding between GigaE and FastE. Think about overflow and bad irq latency. I wouldn't cut buffering at l2 as it averages the peaks. Different trade-offs make sense of course. -- Ueimor - 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/