Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757445Ab0DWVEH (ORCPT ); Fri, 23 Apr 2010 17:04:07 -0400 Received: from mail-bw0-f225.google.com ([209.85.218.225]:41178 "EHLO mail-bw0-f225.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752831Ab0DWVEC convert rfc822-to-8bit (ORCPT ); Fri, 23 Apr 2010 17:04:02 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=oOTlVfCrGmQ70h9knBf4Ufaa+X/n0R8QAwDvs28AzGhsfTu7zaeVHNuRIAGyYsfhwf 1TsBN7NL01PX7FDROvLl7pyAL24p21DPh9xhvr5P6cXM3eem44b2tRR4w9JOrxwggX4u N3TNKilLnSd8DYa41qJqPS2u6TpSOHGpjrapg= MIME-Version: 1.0 In-Reply-To: <20100423135816.23f5861f@nehalam> References: <20100423135816.23f5861f@nehalam> Date: Fri, 23 Apr 2010 23:03:59 +0200 Message-ID: Subject: Re: [PATCH] e100: expose broadcast_disabled as a module option From: Erwan Velu To: Stephen Hemminger Cc: Jeff Kirsher , netdev , David Miller , linux-kernel@vger.kernel.org, jesse.brandeburg@intel.com, bruce.w.allan@intel.com, alexander.h.duyck@intel.com, peter.p.waskiewicz.jr@intel.com, john.ronciak@intel.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3895 Lines: 94 I first tried "ifconfig -broadcast" without any success, so I forced the driver to unset IFF_BROADCAST, the interface didn't showed anymore the BROADCAST option with ifconfig. But I didn't noticed any reduction in the amount of context/switches on my host. I found the broadcast_disabled far more efficient when considering the cpu impact. 2010/4/23 Stephen Hemminger : > On Fri, 23 Apr 2010 13:22:22 -0700 > Jeff Kirsher wrote: > >> On Fri, Apr 23, 2010 at 13:14, Erwan Velu wrote: >> > Hi folks, >> > >> > I've been facing a very noisy network where hundreds broadcast packets >> > were generated every second. >> > When this traffic can't be controlled at the source, there is a side >> > effect on some systems. >> > I was having some idle systems that will never be targeted by this >> > broadcast traffic that got loaded just by receiving that "flood". >> > I mean by loaded that this light hardware was generating 300 >> > context/switches per second. >> > >> > I was looking for many options to avoid this traffic to disturb this >> > hosts and I discovered that the e100 driver was featuring a >> > "broadcast_disabled" configure option. >> > I realize that this option is not controllable, so I wrote this simple >> > patch that expose this option as a module option. >> > This allow me to tell this hosts not to listen anymore this traffic. >> > >> > The result is clearly good as my systems are now running at 21 >> > context/switches while being idle. >> > Hope this patch isn't too bad and could help others that faces the same problem. >> > >> > Patch can be downloaded here : >> > http://konilope.linuxeries.org/e100_broadcast_disabled.patch >> > >> > Even if gmail is eating the inlined, patch, at least that make it >> > easier to read it for humans. >> > If the patch is acked, the downloaded one will be more clean ;) >> > >> > This patch was generated on top of the latest 2.6 torvald's git. >> > Cheers, >> > Erwan >> > >> > Signed-off-by: Erwan Velu >> > >> > diff --git a/drivers/net/e100.c b/drivers/net/e100.c >> > index b997e57..2ba582f 100644 >> > --- a/drivers/net/e100.c >> > +++ b/drivers/net/e100.c >> > @@ -194,12 +194,15 @@ MODULE_FIRMWARE(FIRMWARE_D102E); >> > ?static int debug = 3; >> > ?static int eeprom_bad_csum_allow = 0; >> > ?static int use_io = 0; >> > +static int broadcast_disabled = 0; >> > ?module_param(debug, int, 0); >> > ?module_param(eeprom_bad_csum_allow, int, 0); >> > ?module_param(use_io, int, 0); >> > +module_param(broadcast_disabled, int, 0); >> > ?MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)"); >> > ?MODULE_PARM_DESC(eeprom_bad_csum_allow, "Allow bad eeprom checksums"); >> > ?MODULE_PARM_DESC(use_io, "Force use of i/o access mode"); >> > +MODULE_PARM_DESC(broadcast_disabled, "Filter broadcast packets >> > (0=disabled (default), 1=enabled)"); >> > ?#define DPRINTK(nlevel, klevel, fmt, args...) \ >> > ? ? ? ?(void)((NETIF_MSG_##nlevel & nic->msg_enable) && \ >> > ? ? ? ?printk(KERN_##klevel PFX "%s: %s: " fmt, nic->netdev->name, \ >> > @@ -1131,6 +1134,8 @@ static void e100_configure(struct nic *nic, >> > struct cb *cb, struct sk_buff *skb) >> > ? ? ? ? ? ? ? ?config->promiscuous_mode = 0x1; ? ? ? ? /* 1=on, 0=off */ >> > ? ? ? ?} >> > >> > + ? ? ? config->broadcast_disabled = broadcast_disabled; /* Broadcast filtering */ >> > + >> > ? ? ? ?if (nic->flags & multicast_all) >> > ? ? ? ? ? ? ? ?config->multicast_all = 0x1; ? ? ? ? ? ?/* 1=accept, 0=no */ >> > -- >> >> Adding Netdev... >> > > What is wrong with using existing IFF_BROADCAST flag? > > > -- > -- 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/