From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <48FD7EEF.3070803@cn.fujitsu.com> Date: Tue, 21 Oct 2008 15:04:15 +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> In-Reply-To: <20081021155454.db6888e4.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 List-ID: KAMEZAWA Hiroyuki wrote: > On Tue, 21 Oct 2008 14:20:27 +0800 > Li Zefan wrote: > >>> BTW, "allocate all page_cgroup at boot" patch goes to Linus' git. Wow. >>> >> But seems this patch causes kernel panic at system boot ... (or maybe one of other >> memcg patches?) >> >> I wrote down the panic manually: >> >> BUG: unable to handle kernel NULL pointer dereference at 00000000 >> IP: page_cgroup_zoneinfo + 0xa >> >> Call Trace: >> ? mem_cgroup_charge_common + 0x17d >> ? mem_cgroup_charge >> ? add_to_page_cache_locked >> ? add_to_page_cache_lru >> ? find_or_create_page >> ? __getblk >> ? ext3_get_inode_loc >> ? ext3_iget >> ? ext3_lookup >> >> Tell me if you need extra information. >> > Hmm, it's curious but page_cgroup->page seems to be NULL... > Could you show disassemble code of page_cgroup_zoneinfo() ? > You mean this ? 000881c8 : 881c8: 55 push %ebp 881c9: 8b 50 04 mov 0x4(%eax),%edx 881cc: 8b 40 08 mov 0x8(%eax),%eax 881cf: 89 e5 mov %esp,%ebp 881d1: 5d pop %ebp 881d2: 8b 00 mov (%eax),%eax 881d4: c1 e8 1e shr $0x1e,%eax 881d7: 6b c0 58 imul $0x58,%eax,%eax 881da: 03 42 48 add 0x48(%edx),%eax 881dd: c3 ret > BTW, this happens always ? > Sometimes just freezed, and sometimes panic. It never boots successfully. -- 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