From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f174.google.com (mail-lb0-f174.google.com [209.85.217.174]) by kanga.kvack.org (Postfix) with ESMTP id 3EF036B007B for ; Thu, 29 Jan 2015 18:26:35 -0500 (EST) Received: by mail-lb0-f174.google.com with SMTP id f15so33711501lbj.5 for ; Thu, 29 Jan 2015 15:26:34 -0800 (PST) Received: from mail-lb0-x231.google.com (mail-lb0-x231.google.com. [2a00:1450:4010:c04::231]) by mx.google.com with ESMTPS id e5si8809060lae.71.2015.01.29.15.26.32 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 29 Jan 2015 15:26:33 -0800 (PST) Received: by mail-lb0-f177.google.com with SMTP id p9so33692914lbv.8 for ; Thu, 29 Jan 2015 15:26:32 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20150129081643.GK25850@nuc-i3427.alporthouse.com> References: <20150128084852.GC28132@nuc-i3427.alporthouse.com> <20150128143242.GF6542@dhcp22.suse.cz> <20150129081643.GK25850@nuc-i3427.alporthouse.com> Date: Fri, 30 Jan 2015 09:26:32 +1000 Message-ID: Subject: Re: [Intel-gfx] memcontrol.c BUG From: Dave Airlie Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Chris Wilson , Michal Hocko , Dave Airlie , Johannes Weiner , "intel-gfx@lists.freedesktop.org" , Hugh Dickins , Tejun Heo , Vladimir Davydov , Jet Chen , Felipe Balbi , Andrew Morton , Linux Memory Management List On 29 January 2015 at 18:16, Chris Wilson wrote: > On Wed, Jan 28, 2015 at 03:32:43PM +0100, Michal Hocko wrote: >> On Wed 28-01-15 08:48:52, Chris Wilson wrote: >> > On Wed, Jan 28, 2015 at 08:13:06AM +1000, Dave Airlie wrote: >> > > https://bugzilla.redhat.com/show_bug.cgi?id=1165369 >> > > >> > > ov 18 09:23:22 elissa.gathman.org kernel: page:f5e36a40 count:2 >> > > mapcount:0 mapping: (null) index:0x0 >> > > Nov 18 09:23:22 elissa.gathman.org kernel: page flags: >> > > 0x80090029(locked|uptodate|lru|swapcache|swapbacked) >> > > Nov 18 09:23:22 elissa.gathman.org kernel: page dumped because: >> > > VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage)) >> > > Nov 18 09:23:23 elissa.gathman.org kernel: ------------[ cut here ]------------ >> > > Nov 18 09:23:23 elissa.gathman.org kernel: kernel BUG at mm/memcontrol.c:6733! >> >> I guess this matches the following bugon in your kernel: >> VM_BUG_ON_PAGE(!lrucare && PageLRU(oldpage), oldpage); >> >> so the oldpage is on the LRU list already. I am completely unfamiliar >> with 965GM but is the page perhaps shared with somebody with a different >> gfp mask requirement (e.g. userspace accessing the memory via mmap)? So >> the other (racing) caller didn't need to move the page and put it on >> LRU. > > Generally, yes. The shmemfs filp is exported through a vm_mmap() as well > as pinned into the GPU via shmem_read_mapping_page_gfp(). But I would > not expect that to be the case very often, if at all, on 965GM as the > two access paths are incoherent. Still it sounds promising, hopefully > Dave can put it into a fedora kernel for testing? http://kojipkgs.fedoraproject.org/scratch/airlied/task_8760024/ done, also asked on the bug for testers. Dave. -- 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