From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 7AF4F6B0027 for ; Mon, 16 Apr 2018 12:38:00 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id q15so9718431pff.15 for ; Mon, 16 Apr 2018 09:38:00 -0700 (PDT) Received: from NAM01-BY2-obe.outbound.protection.outlook.com (mail-by2nam01on0091.outbound.protection.outlook.com. [104.47.34.91]) by mx.google.com with ESMTPS id d17si9616201pgo.310.2018.04.16.09.37.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 16 Apr 2018 09:37:59 -0700 (PDT) From: Sasha Levin Subject: Re: [PATCH AUTOSEL for 4.14 015/161] printk: Add console owner and waiter logic to load balance console writes Date: Mon, 16 Apr 2018 16:37:56 +0000 Message-ID: <20180416163754.GD2341@sasha-vm> References: <20180409001936.162706-15-alexander.levin@microsoft.com> <20180409082246.34hgp3ymkfqke3a4@pathway.suse.cz> <20180415144248.GP2341@sasha-vm> <20180416093058.6edca0bb@gandalf.local.home> <20180416113629.2474ae74@gandalf.local.home> <20180416160200.GY2341@sasha-vm> <20180416121224.2138b806@gandalf.local.home> <20180416161911.GA2341@sasha-vm> <20180416123019.4d235374@gandalf.local.home> In-Reply-To: <20180416123019.4d235374@gandalf.local.home> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-ID: <6F4DE755B469B843A412DBA81A8E3C33@namprd21.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Steven Rostedt Cc: Linus Torvalds , Petr Mladek , "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "linux-mm@kvack.org" , Cong Wang , Dave Hansen , Johannes Weiner , Mel Gorman , Michal Hocko , Vlastimil Babka , Peter Zijlstra , Jan Kara , Mathieu Desnoyers , Tetsuo Handa , Byungchul Park , Tejun Heo , Pavel Machek On Mon, Apr 16, 2018 at 12:30:19PM -0400, Steven Rostedt wrote: >On Mon, 16 Apr 2018 16:19:14 +0000 >Sasha Levin wrote: > >> >Wait! What does that mean? What's the purpose of stable if it is as >> >broken as mainline? >> >> This just means that if there is a fix that went in mainline, and the >> fix is broken somehow, we'd rather take the broken fix than not. >> >> In this scenario, *something* will be broken, it's just a matter of >> what. We'd rather have the same thing broken between mainline and >> stable. > >Honestly, I think that removes all value of the stable series. I >remember when the stable series were first created. People were saying >that it wouldn't even get to more than 5 versions, because the bar for >backporting was suppose to be very high. Today it's just a fork of the >kernel at a given version. No more features, but we will be OK with >regressions. I'm struggling to see what the benefit of it is suppose to >be? It's not "OK with regressions". Let's look at a hypothetical example: You have a 4.15.1 kernel that has a broken printf() behaviour so that when you: pr_err("%d", 5) Would print: "Microsoft Rulez" Bad, right? So you went ahead and fixed it, and now it prints "5" as you might expect. But alas, with your patch, running: pr_err("%s", "hi!") Would show a cat picture for 5 seconds. Should we take your patch in -stable or not? If we don't, we're stuck with the original issue while the mainline kernel will behave differently, but if we do - we introduce a new regression. So it's not the case that a -stable kernel will have *more* regression, it'll just have similar ones to mainline.=