Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 8 Oct 2001 11:21:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 8 Oct 2001 11:20:55 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:49967 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Mon, 8 Oct 2001 11:20:36 -0400 Date: Mon, 8 Oct 2001 17:19:52 +0200 From: Andrea Arcangeli To: Alan Cox Cc: Ingo Molnar , jamal , linux-kernel@vger.kernel.org, Alexey Kuznetsov , Robert Olsson , Benjamin LaHaise , netdev@oss.sgi.com, Linus Torvalds Subject: Re: [announce] [patch] limiting IRQ load, irq-rewrite-2.4.11-B5 Message-ID: <20011008171952.Z726@athlon.random> In-Reply-To: <20011008023118.L726@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from alan@lxorguk.ukuu.org.uk on Mon, Oct 08, 2001 at 04:00:36PM +0100 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 08, 2001 at 04:00:36PM +0100, Alan Cox wrote: > > Of course we agree that such a "polling router/firewall" behaviour must > > not be the default but it must be enabled on demand by the admin via > > sysctl or whatever else userspace API. And I don't see any problem with > > that. > > No I don't agree. "Stop random end users crashing my machine at will" is not > a magic sysctl option - its a default. The "random user hanging my machine" has nothing to do with "it is ok in a router to dedicate one cpu to polling". The whole email was about "in a router is ok to poll" I'm not saying "to solve the food problem you should be forced to turn on polling". I also said that if you turn on polling you also solve the DoS, yes, but that was just a side note. My only implicit thought about the side note was that most machines sensible to the DoS are routers where people wants the max performance and where they can dedicate one cpu (also in UP) to polling. So the only argument I can make is that the amount of userbase concerned about the "current" hardirq DoS would decrease significantly if polling method would becomes available in linux. I'm certainly not saying that the "stop random user crashing my machine at will" should be a sysctl option and not the default. Andrea - 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/