From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id m9LB1KQ9025239 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 21 Oct 2008 20:01:20 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 07FD52AC025 for ; Tue, 21 Oct 2008 20:01:20 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id C977A12C04A for ; Tue, 21 Oct 2008 20:01:19 +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 816451DB8040 for ; Tue, 21 Oct 2008 20:01:19 +0900 (JST) Received: from ml12.s.css.fujitsu.com (ml12.s.css.fujitsu.com [10.249.87.102]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 2B67E1DB803B for ; Tue, 21 Oct 2008 20:01:19 +0900 (JST) Date: Tue, 21 Oct 2008 20:00:53 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [memcg BUG] unable to handle kernel NULL pointer derefence at 00000000 Message-Id: <20081021200053.fcd39f16.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <48FDB584.7080608@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> <20081021191417.02ab97cc.kamezawa.hiroyu@jp.fujitsu.com> <48FDB584.7080608@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, Ingo Molnar List-ID: On Tue, 21 Oct 2008 18:57:08 +0800 Li Zefan wrote: > KAMEZAWA Hiroyuki wrote: > > 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 ? > > > > Yes, curruption. I didn't find informatation about initialization failure. > > > What happens if replacing __alloc_bootmem() with vmalloc() in page_cgroup.c init ? > > > > So I did this change, and the box booted up without any problem. > Ok, I wonder bootmem we got is freed...or reset to 0. Hmm..thank you very much! Thanks, -Kame > diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c > index 5d86550..82a30b1 100644 > --- a/mm/page_cgroup.c > +++ b/mm/page_cgroup.c > @@ -48,8 +48,7 @@ static int __init alloc_node_page_cgroup(int nid) > > table_size = sizeof(struct page_cgroup) * nr_pages; > > - base = __alloc_bootmem_node_nopanic(NODE_DATA(nid), > - table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS)); > + base = vmalloc_node(table_size, nid); > if (!base) > return -ENOMEM; > for (index = 0; index < nr_pages; index++) { > > -- 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