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 D15386B007E for ; Thu, 2 Jun 2016 19:08:27 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id c84so78739405pfc.3 for ; Thu, 02 Jun 2016 16:08:27 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net. [150.101.137.141]) by mx.google.com with ESMTP id q6si1440296paq.16.2016.06.02.16.08.25 for ; Thu, 02 Jun 2016 16:08:26 -0700 (PDT) Date: Fri, 3 Jun 2016 09:08:13 +1000 From: Dave Chinner Subject: Re: shrink_active_list/try_to_release_page bug? (was Re: xfs trace in 4.4.2 / also in 4.3.3 WARNING fs/xfs/xfs_aops.c:1232 xfs_vm_releasepage) Message-ID: <20160602230813.GQ12670@dastard> References: <574BEA84.3010206@profihost.ag> <20160530223657.GP26977@dastard> <20160531010724.GA9616@bbox> <20160531025509.GA12670@dastard> <20160531035904.GA17371@bbox> <20160531060712.GC12670@dastard> <574D2B1E.2040002@profihost.ag> <20160531073119.GD12670@dastard> <575022D2.7030502@profihost.ag> <57502A2E.60702@applied-asynchrony.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <57502A2E.60702@applied-asynchrony.com> Sender: owner-linux-mm@kvack.org List-ID: To: Holger =?iso-8859-1?Q?Hoffst=E4tte?= Cc: Stefan Priebe - Profihost AG , linux-mm@kvack.org, Minchan Kim , Brian Foster , linux-kernel@vger.kernel.org, "xfs@oss.sgi.com" On Thu, Jun 02, 2016 at 02:44:30PM +0200, Holger Hoffstatte wrote: > On 06/02/16 14:13, Stefan Priebe - Profihost AG wrote: > > > > Am 31.05.2016 um 09:31 schrieb Dave Chinner: > >> On Tue, May 31, 2016 at 08:11:42AM +0200, Stefan Priebe - Profihost AG wrote: > >>>> I'm half tempted at this point to mostly ignore this mm/ behavour > >>>> because we are moving down the path of removing buffer heads from > >>>> XFS. That will require us to do different things in ->releasepage > >>>> and so just skipping dirty pages in the XFS code is the best thing > >>>> to do.... > >>> > >>> does this change anything i should test? Or is 4.6 still the way to go? > >> > >> Doesn't matter now - the warning will still be there on 4.6. I think > >> you can simply ignore it as the XFS code appears to be handling the > >> dirty page that is being passed to it correctly. We'll work out what > >> needs to be done to get rid of the warning for this case, wether it > >> be a mm/ change or an XFS change. > > > > Any idea what i could do with 4.4.X? Can i safely remove the WARN_ONCE > > statement? > > By definition it won't break anything since it's just a heads-up message, > so yes, it should be "safe". However if my understanding of the situation > is correct, mainline commit f0281a00fe "mm: workingset: only do workingset > activations on reads" (+ friends) in 4.7 should effectively prevent this > from happenning. Can someone confirm or deny this? I don't think it will. The above commits will avoid putting /write-only/ dirty pages on the active list from the write() syscall vector, but it won't prevent pages that are read first then dirtied from ending up on the active list. e.g. a mmap write will first read the page from disk to populate the page (hence it ends up on the active list), then the page gets dirtied and ->page_mkwrite is called to tell the filesystem.... Cheers, Dave. -- Dave Chinner david@fromorbit.com -- 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