From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f197.google.com (mail-io0-f197.google.com [209.85.223.197]) by kanga.kvack.org (Postfix) with ESMTP id 451316B0005 for ; Thu, 3 May 2018 09:28:10 -0400 (EDT) Received: by mail-io0-f197.google.com with SMTP id y4-v6so17508749iod.5 for ; Thu, 03 May 2018 06:28:10 -0700 (PDT) Received: from NAM02-BL2-obe.outbound.protection.outlook.com (mail-bl2nam02on0108.outbound.protection.outlook.com. [104.47.38.108]) by mx.google.com with ESMTPS id 23-v6si11058273itj.37.2018.05.03.06.28.08 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 03 May 2018 06:28:09 -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: Thu, 3 May 2018 13:28:04 +0000 Message-ID: <20180503132800.GH18390@sasha-vm> References: <20180416161911.GA2341@sasha-vm> <20180416123019.4d235374@gandalf.local.home> <20180416163754.GD2341@sasha-vm> <20180416170604.GC11034@amd> <20180416172327.GK2341@sasha-vm> <20180417114144.ov27khlig5thqvyo@quack2.suse.cz> <20180417133149.GR2341@sasha-vm> <20180417155549.6lxmoiwnlwtwdgld@quack2.suse.cz> <20180417161933.GY2341@sasha-vm> <20180503093651.GC32180@amd> In-Reply-To: <20180503093651.GC32180@amd> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-ID: <889546DA857A2243B0CBD37E2EF4F4DB@namprd21.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Pavel Machek Cc: "jacek.anaszewski@gmail.com" , "Rafael J. Wysocki" , Jan Kara , Steven Rostedt , 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 , Mathieu Desnoyers , Tetsuo Handa , Byungchul Park , Tejun Heo On Thu, May 03, 2018 at 11:36:51AM +0200, Pavel Machek wrote: >On Tue 2018-04-17 16:19:35, Sasha Levin wrote: >> On Tue, Apr 17, 2018 at 05:55:49PM +0200, Jan Kara wrote: >> >On Tue 17-04-18 13:31:51, Sasha Levin wrote: >> >> We may be able to guesstimate the 'regression chance', but there's no >> >> way we can guess the 'annoyance' once. There are so many different us= e >> >> cases that we just can't even guess how many people would get "annoye= d" >> >> by something. >> > >> >As a maintainer, I hope I have reasonable idea what are common use case= s >> >for my subsystem. Those I cater to when estimating 'annoyance'. Sure I = don't >> >know all of the use cases so people doing unusual stuff hit more bugs a= nd >> >have to report them to get fixes included in -stable. But for me this i= s a >> >preferable tradeoff over the risk of regression so this is the rule I u= se >> >when tagging for stable. Now I'm not a -stable maintainer and I fully a= gree >> >with "those who do the work decide" principle so pick whatever patches = you >> >think are appropriate, I just wanted explain why I don't think more pat= ches >> >in stable are necessarily good. >> >> The AUTOSEL story is different for subsystems that don't do -stable, and >> subsystems that are actually doing the work (like yourself). >> >> I'm not trying to override active maintainers, I'm trying to help them >> make decisions. > >Ok, cool. Can you exclude LED subsystem, Hibernation and Nokia N900 >stuff from autosel work? Curiousity got me, and I had to see what these subsystems do as far as stable commits: $ git log --oneline --grep 'stable@vger' --since=3D"01-01-2016" kernel/powe= r drivers/leds drivers/media/i2c/et8ek8 drivers/media/i2c/ad5820.c arch/x86= /kernel/acpi/ | wc -l 7 Which got me a bit surprised: maybe indeed leds is mostly fine, but hibernation is definitely tricky, I've been stung by it a few times... So why not pick something an actual user reported, and see how that was dealt with? Googling first showed this: https://bugzilla.kernel.org/show_bug.cgi?id=3D97201 Which was fixed by: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/= ?id=3Dbdbc98abb3aa323f6323b11db39c740e6f8fc5b1 But that's not in any -stable tree. Hmm.. ok.. Next one on google was: https://bugzilla.kernel.org/show_bug.cgi?id=3D117971 Which, in turn, was fixed by: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/= ?id=3D5b3f249c94ce1f46bacd9814385b0ee2d1ae52f3 Oh look at that, it's not in -stable either... So seeing how you have concerns with my selection of -stable commits, maybe you could explain to me why these commits didn't end up in -stable?=