From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932857AbXDFUcF (ORCPT ); Fri, 6 Apr 2007 16:32:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932798AbXDFUcE (ORCPT ); Fri, 6 Apr 2007 16:32:04 -0400 Received: from mail.tmr.com ([64.65.253.246]:59245 "EHLO gaimboi.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932857AbXDFUcA (ORCPT ); Fri, 6 Apr 2007 16:32:00 -0400 Message-ID: <4616AE9C.9060400@tmr.com> Date: Fri, 06 Apr 2007 16:33:32 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 MIME-Version: 1.0 Newsgroups: gmane.linux.kernel To: Jan Engelhardt CC: Ken Chen , Tomas M , linux-kernel@vger.kernel.org Subject: Re: [patch] remove artificial software max_loop limit References: <20070330141524.5f6cff29.akpm@linux-foundation.org> <460FE380.2050608@slax.org> <460FE478.9070901@slax.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jan Engelhardt wrote: > On Apr 1 2007 11:10, Ken Chen wrote: >> On 4/1/07, Tomas M wrote: >> >>> I believe that IF you _really_ need to preserve the max_loop module >>> parameter, then the parameter should _not_ be ignored, rather it >>> should have the same function like before - to limit the loop driver >>> so if you use max_loop=10 for example, it should not allow loop.c to >>> create more than 10 loops. >> Blame on the dual meaning of max_loop that it uses currently: to >> initialize a set of loop devices and as a side effect, it also sets >> the upper limit. People are complaining about the former constrain, >> isn't it? Does anyone uses the 2nd meaning of upper limit? > > Who cares if the user specifies max_loop=8 but still is able to open up > /dev/loop8, loop9, etc.? max_loop=X basically meant (at least to me) > "have at least X" loops ready. > You have just come up with a really good reason not to do unlimited loops. With the current limit people can count on a script mounting files, or similar, to neither loop for a VERY long time or to eat their memory. Whatever you think of programs without limit checking, this falls in the range of expecting an unsigned char to have a certain upper bound, and argues that the default limit should be the current limit and that setting a lower bound should work as a real and enforced limit. If a new capability is being added, and I think it's a great one, then people using the capability should be the ones explicitly doing something different. Plauger's law of least astonishment. -- Bill Davidsen "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot