From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id CD4856B0022 for ; Mon, 16 Apr 2018 13:06:06 -0400 (EDT) Received: by mail-wr0-f197.google.com with SMTP id u56so10419470wrf.18 for ; Mon, 16 Apr 2018 10:06:06 -0700 (PDT) Received: from atrey.karlin.mff.cuni.cz (atrey.karlin.mff.cuni.cz. [195.113.26.193]) by mx.google.com with ESMTPS id h1si9313838wrc.271.2018.04.16.10.06.05 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Apr 2018 10:06:05 -0700 (PDT) Date: Mon, 16 Apr 2018 19:06:04 +0200 From: Pavel Machek Subject: Re: [PATCH AUTOSEL for 4.14 015/161] printk: Add console owner and waiter logic to load balance console writes Message-ID: <20180416170604.GC11034@amd> References: <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> <20180416163754.GD2341@sasha-vm> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="B4IIlcmfBL/1gGOG" Content-Disposition: inline In-Reply-To: <20180416163754.GD2341@sasha-vm> Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: 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 , Jan Kara , Mathieu Desnoyers , Tetsuo Handa , Byungchul Park , Tejun Heo --B4IIlcmfBL/1gGOG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon 2018-04-16 16:37:56, Sasha Levin wrote: > 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? >=20 > It's not "OK with regressions". >=20 > Let's look at a hypothetical example: You have a 4.15.1 kernel that has > a broken printf() behaviour so that when you: >=20 > pr_err("%d", 5) >=20 > Would print: >=20 > "Microsoft Rulez" >=20 > Bad, right? So you went ahead and fixed it, and now it prints "5" as you > might expect. But alas, with your patch, running: >=20 > pr_err("%s", "hi!") >=20 > Would show a cat picture for 5 seconds. >=20 > 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. Of course not. - It must be obviously correct and tested. If it introduces new bug, it is not correct, and certainly not obviously correct. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --B4IIlcmfBL/1gGOG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlrU1/wACgkQMOfwapXb+vIjgQCdEVO1o/y2VmXGEcZZyPdYbKfc GZoAn3Hi6VsBPbA2sH/ZU7m8YVz1KnWd =jdee -----END PGP SIGNATURE----- --B4IIlcmfBL/1gGOG--