From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48FDA6D4.3090809@cn.fujitsu.com> Date: Tue, 21 Oct 2008 17:54:28 +0800 From: Li Zefan MIME-Version: 1.0 Subject: Re: [memcg BUG] unable to handle kernel NULL pointer derefence at 00000000 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> In-Reply-To: <20081021182551.0158a47b.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: balbir@linux.vnet.ibm.com, Paul Menage , Daisuke Nishimura , linux-mm@kvack.org, mel@csn.ul.ie List-ID: 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 > == > Index: linux-2.6.27/mm/memcontrol.c > =================================================================== > --- linux-2.6.27.orig/mm/memcontrol.c > +++ linux-2.6.27/mm/memcontrol.c > @@ -544,6 +544,10 @@ static int mem_cgroup_charge_common(stru > > goto done; > } > + > + printk(KERN_DEBUG "pc %p pc->page %p page %p pfn %lx\n", > + pc, pc->page, page, page_to_pfn(page)); > + BUG_ON(!pc->page); > pc->mem_cgroup = mem; > /* > * If a page is accounted as a page cache, insert to inactive list. > > > -- 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