From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f70.google.com (mail-lf0-f70.google.com [209.85.215.70]) by kanga.kvack.org (Postfix) with ESMTP id 24F996B0038 for ; Thu, 29 Dec 2016 17:22:31 -0500 (EST) Received: by mail-lf0-f70.google.com with SMTP id t196so142039282lff.3 for ; Thu, 29 Dec 2016 14:22:31 -0800 (PST) Received: from mail-lf0-x22d.google.com (mail-lf0-x22d.google.com. [2a00:1450:4010:c07::22d]) by mx.google.com with ESMTPS id d5si31718226lfc.359.2016.12.29.14.22.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Dec 2016 14:22:29 -0800 (PST) Received: by mail-lf0-x22d.google.com with SMTP id c13so228431024lfg.0 for ; Thu, 29 Dec 2016 14:22:29 -0800 (PST) From: Michal Nazarewicz Subject: Re: [PATCH] mm: Drop "PFNs busy" printk in an expected path. In-Reply-To: <87wpeitzld.fsf@eliezer.anholt.net> References: <20161229023131.506-1-eric@anholt.net> <20161229091256.GF29208@dhcp22.suse.cz> <87wpeitzld.fsf@eliezer.anholt.net> Date: Thu, 29 Dec 2016 23:22:20 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Eric Anholt , Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-stable , "Robin H. Johnson" , Vlastimil Babka , Marek Szyprowski On Thu, Dec 29 2016, Eric Anholt wrote: > Michal Hocko writes: > >> This has been already brought up >> http://lkml.kernel.org/r/20161130092239.GD18437@dhcp22.suse.cz and there >> was a proposed patch for that which ratelimited the output >> http://lkml.kernel.org/r/20161130132848.GG18432@dhcp22.suse.cz resp. >> http://lkml.kernel.org/r/robbat2-20161130T195244-998539995Z@orbis-terrar= um.net >> >> then the email thread just died out because the issue turned out to be a >> configuration issue. Michal indicated that the message might be useful >> so dropping it completely seems like a bad idea. I do agree that >> something has to be done about that though. Can we reconsider the >> ratelimit thing? > > I agree that the rate of the message has gone up during 4.9 -- it used > to be a few per second. Sounds like a regression which should be fixed. This is why I don=E2=80=99t think removing the message is a good idea. If = you suddenly see a lot of those messages, something changed for the worse. If you remove this message, you will never know. > However, if this is an expected path during normal operation, This depends on your definition of =E2=80=98expected=E2=80=99 and =E2=80=98= normal=E2=80=99. In general, I would argue that the fact those ever happen is a bug somewhere in the kernel =E2=80=93 if memory is allocated as movable, it sho= uld be movable damn it! > we shouldn't be clogging dmesg with it at all. So, I'd rather we go > with this patch, that is unless the KERN_DEBUG in your ratelimit patch > would keep it out of journald as well (un-ratelimited, journald was > eating 10% of a CPU processing the message, and I'd rather it not be > getting logged at all). --=20 Best regards =E3=83=9F=E3=83=8F=E3=82=A6 =E2=80=9C=F0=9D=93=B6=F0=9D=93=B2=F0=9D=93=B7= =F0=9D=93=AA86=E2=80=9D =E3=83=8A=E3=82=B6=E3=83=AC=E3=83=B4=E3=82=A4=E3=83= =84 =C2=ABIf at first you don=E2=80=99t succeed, give up skydiving=C2=BB -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org