From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m4.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id m9LAEibC021341 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 21 Oct 2008 19:14:44 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 4473F2AC026 for ; Tue, 21 Oct 2008 19:14:44 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1B7B112C044 for ; Tue, 21 Oct 2008 19:14:44 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 05F011DB8037 for ; Tue, 21 Oct 2008 19:14:44 +0900 (JST) Received: from ml11.s.css.fujitsu.com (ml11.s.css.fujitsu.com [10.249.87.101]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id B9C2F1DB803B for ; Tue, 21 Oct 2008 19:14:43 +0900 (JST) Date: Tue, 21 Oct 2008 19:14:17 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [memcg BUG] unable to handle kernel NULL pointer derefence at 00000000 Message-Id: <20081021191417.02ab97cc.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <48FDA6D4.3090809@cn.fujitsu.com> References: <20081017194804.fce28258.nishimura@mxp.nes.nec.co.jp> <20081017195601.0b9abda1.nishimura@mxp.nes.nec.co.jp> <6599ad830810201253u3bca41d4rabe48eb1ec1d529f@mail.gmail.com> <20081021101430.d2629a81.kamezawa.hiroyu@jp.fujitsu.com> <48FD6901.6050301@linux.vnet.ibm.com> <20081021143955.eeb86d49.kamezawa.hiroyu@jp.fujitsu.com> <48FD74AB.9010307@cn.fujitsu.com> <20081021155454.db6888e4.kamezawa.hiroyu@jp.fujitsu.com> <48FD7EEF.3070803@cn.fujitsu.com> <20081021161621.bb51af90.kamezawa.hiroyu@jp.fujitsu.com> <48FD82E3.9050502@cn.fujitsu.com> <20081021171801.4c16c295.kamezawa.hiroyu@jp.fujitsu.com> <48FD943D.5090709@cn.fujitsu.com> <20081021175735.0c3d3534.kamezawa.hiroyu@jp.fujitsu.com> <48FD9D30.2030500@cn.fujitsu.com> <20081021182551.0158a47b.kamezawa.hiroyu@jp.fujitsu.com> <48FDA6D4.3090809@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Li Zefan Cc: balbir@linux.vnet.ibm.com, Paul Menage , Daisuke Nishimura , linux-mm@kvack.org, mel@csn.ul.ie List-ID: On Tue, 21 Oct 2008 17:54:28 +0800 Li Zefan wrote: > KAMEZAWA Hiroyuki wrote: > > On Tue, 21 Oct 2008 17:13:20 +0800 > > Li Zefan wrote: > > > >> KAMEZAWA Hiroyuki wrote: > >>> On Tue, 21 Oct 2008 16:35:09 +0800 > >>> Li Zefan wrote: > >>> > >>>> KAMEZAWA Hiroyuki wrote: > >>>>> On Tue, 21 Oct 2008 15:21:07 +0800 > >>>>> Li Zefan wrote: > >>>>>> dmesg is attached. > >>>>>> > >>>>> Thanks....I think I caught some. (added Mel Gorman to CC:) > >>>>> > >>>>> NODE_DATA(nid)->spanned_pages just means sum of zone->spanned_pages in node. > >>>>> > >>>>> So, If there is a hole between zone, node->spanned_pages doesn't mean > >>>>> length of node's memmap....(then, some hole can be skipped.) > >>>>> > >>>>> OMG....Could you try this ? > >>>>> > >>>> No luck, the same bug still exists. :( > >>>> > >>> This is a little fixed one.. > >>> > >> I tried the patch, but it doesn't solve the problem.. > >> > > Hmm.. Can you catch "pfn" of troublesome page_cgroup ? > > By patch like this ? > > > > I got what you want: > > pc c1d589dc pc->page 00000000 page c105f67c pfn 1d5b > ... > pc c1d589f0 pc->page 00000000 page c105f6b0 pfn 1d5c > Oh! thanks...but it seems pc->page is NULL in the middle of ZONE_NORMAL.. == Normal 0x00001000 -> 0x000373fe == This is appearently in the range of page_cgroup initialization. (if pgdat->node_page_cgroup is initalized correctly...) I think write to page_cgroup->page happens only at initialization. Hmm ? not initilization failure but curruption ? What happens if replacing __alloc_bootmem() with vmalloc() in page_cgroup.c init ? Thanks, -Kame -- 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