Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752137AbZG1TJk (ORCPT ); Tue, 28 Jul 2009 15:09:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751548AbZG1TJk (ORCPT ); Tue, 28 Jul 2009 15:09:40 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:44877 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751320AbZG1TJj (ORCPT ); Tue, 28 Jul 2009 15:09:39 -0400 Date: Tue, 28 Jul 2009 12:08:57 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Alan Cox cc: OGAWA Hirofumi , "Aneesh Kumar K.V" , "Rafael J. Wysocki" , Ray Lee , LKML , Andrew Morton Subject: Re: [PATCH] kdesu broken In-Reply-To: <20090728195651.3a402a31@lxorguk.ukuu.org.uk> Message-ID: References: <20090725163251.50e6f546@lxorguk.ukuu.org.uk> <87bpn7mzli.fsf@devron.myhome.or.jp> <20090727115723.1e8de60e@lxorguk.ukuu.org.uk> <873a8iqqgv.fsf@devron.myhome.or.jp> <20090727142303.41096bf5@lxorguk.ukuu.org.uk> <877hxujkuv.fsf@devron.myhome.or.jp> <20090727145805.690afe5d@lxorguk.ukuu.org.uk> <87fxci6ub9.fsf@devron.myhome.or.jp> <20090727161424.GA4233@skywalker> <20090727174252.2d987830@lxorguk.ukuu.org.uk> <20090727171213.GB4233@skywalker> <87skgikjr8.fsf@devron.myhome.or.jp> <20090727222010.1a5efb7b@lxorguk.ukuu.org.uk> <87r5w19xsb.fsf@devron.myhome.or.jp> <20090728112203.7b70adba@lxorguk.ukuu.org.uk> <20090728174213.5e927428@lxorguk.ukuu.org.uk> <20090728180649.596c5412@lxorguk.ukuu.org.uk> <20090728195651.3a402a31@lxorguk.ukuu.org.uk> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2789 Lines: 70 On Tue, 28 Jul 2009, Alan Cox wrote: > > In which case you need the write to be synchronous to the ldisc > processing. Which is what tty->low_latency = 1 did. That provides your > required causality. > > So what exactly is the problem. The problem is that you seem to be arguing against the _nicer_ fix, that also makes more conceptual sense, and that doesn't even depend on the whole low-latency hackery. And I don't see why you argue that. Furthermore, you have been CONTINUALLY arguing that emacs is buggy. Without any logic to back that up what-so-ever. You argued that just a few minutes ago. Why? Why are you making those outlandish claims? What I'm so unhappy about is that your whole reaction to it - from the beginning - was to blame anything but the patch that caused it, and that it was bisected down to. Why? Why blame emacs? Why call user land buggy, when the bug was introduced by you, and was in the kernel? Why are you fighting it? Why did it take so long to admit that all the regressions were kernel problems? Why were you trying to dismiss the regression report as a user-land bug from the very beginning? Let me quote one of your first emails as I got cc'd on this thread: > > See the thread starting here: ("possible regression with pty.c commit") > > http://lkml.org/lkml/2009/7/11/125 > > Thanks for the pointer. > > Well, I thought we were expected to avoid breaking existing user space, even > if that were buggy etc. I don't know where you got that idea from. Avoiding breaking user space unneccessarily is good but if its buggy you often can't do anything about it. That was you talking to Rafael, who tracks regressions, and trying to argue that it wasn't a kernel bug (both in the double quoted thing and in the final one). And no, that was not a fluke. TODAY, you sent out an email saying that EWOUDLBLOCK/EAGAIN would be "correct". Despite me having told you that it _clearly_ is not correct, and despite you knowing that it breaks user space. WHY? Quite frankly, I don't understand why I should even have to bring these issues up. You should have tried to fix the problem immediately, without arguing against fixing the kernel. Without blaming user space. Without making idiotic excuses for bad kernel behavior. The fact is, breaking regular user applications is simply not acceptable. Trying to blame kernel breakage on the app being "buggy" is not ok. And arguing for almost a week against fixing it - that's just crazy. Linus -- 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/