From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <51E593B6.1050607@zytor.com> Date: Tue, 16 Jul 2013 11:40:54 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 To: David Lang CC: Willy Tarreau , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, ksummit-2013-discuss@lists.linux-foundation.org, torvalds@linux-foundation.org Subject: Re: [Ksummit-2013-discuss] When to push bug fixes to mainline References: <20130711214830.611455274@linuxfoundation.org> <20130712005023.GB31005@thunk.org> <20130712051451.GC25815@1wt.eu> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: On 07/16/2013 12:19 AM, David Lang wrote: > On Fri, 12 Jul 2013, Willy Tarreau wrote: > >> And maybe in the end, having 1/10 patch cause a regression is not *that* >> dramatic, and probably less than not fixing the 9 other bugs. In one case >> we rely on -stable to merge the 10 fixes, and on the other case we'd rely >> on -stable to just revert one of them. > > Apologies for the late post, I'm catching up on things, but this jumped > out at me. > > We went through a LOT of pain several years ago when people got into the > mindset that a patch was acceptable if it fixed more people than it > broke. eliminating that mindset did wonders for kernel stability. > > Regressions are a lot more of a negative than bugfixes are a positive, a > 10:1 ratio of fixes to regressions is _not_ good enough. > In my opinion, there is one exception, and that is when the problem being fixed is much more severe than the fix. *In particular* two cases: permanently damaging hardware and corrupting data. For example: no boot, as severe as it is, is much better than either of these two scenarios. -hpa