From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx156.postini.com [74.125.245.156]) by kanga.kvack.org (Postfix) with SMTP id DBDA66B002B for ; Wed, 26 Dec 2012 10:14:48 -0500 (EST) Received: by mail-ob0-f173.google.com with SMTP id xn12so7804142obc.4 for ; Wed, 26 Dec 2012 07:14:48 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <50DAFA8C.2030906@redhat.com> References: <535932623.34838584.1356410331076.JavaMail.root@redhat.com> <692539675.35132464.1356520940797.JavaMail.root@redhat.com> <50DAFA8C.2030906@redhat.com> Date: Wed, 26 Dec 2012 23:14:47 +0800 Message-ID: Subject: Re: BUG: unable to handle kernel NULL pointer dereference at 0000000000000500 From: Hillf Danton Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Zhouping Liu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ingo Molnar , Johannes Weiner , mgorman@suse.de, hughd@google.com, Andrea Arcangeli , "devendra.aaru" , Jongman Heo On Wed, Dec 26, 2012 at 9:24 PM, Zhouping Liu wrote: > On 12/26/2012 08:01 PM, Hillf Danton wrote: >> >> On Wed, Dec 26, 2012 at 7:22 PM, Zhouping Liu wrote: >>> >>> Hello everyone, >>> >>> The latest mainline(637704cbc95c) would trigger the following error when >>> the system was under >>> some pressure condition(in my testing, I used oom01 case inside LTP test >>> suite to trigger the issue): >>> >>> [ 5462.920151] BUG: unable to handle kernel NULL pointer dereference at >>> 0000000000000500 >>> [ 5462.927991] IP: [] wait_iff_congested+0x59/0x140 >>> [ 5462.934176] PGD 0 >>> [ 5462.936191] Oops: 0000 [#2] SMP >>> [ 5462.939428] Modules linked in: lockd sunrpc iptable_mangle ipt_REJECT >>> nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ebtable_filter >>> ebtables ip6table_filter ip6_tables iptable_filter ip_tabled >>> [ 5462.984261] CPU 13 >>> [ 5462.986184] Pid: 117, comm: kswapd3 Tainted: G D 3.8.0-rc1+ >>> #1 Dell Inc. PowerEdge M905/0D413F >>> [ 5462.995814] RIP: 0010:[] [] >>> wait_iff_congested+0x59/0x140 >>> [ 5463.004411] RSP: 0018:ffff88007c97fd48 EFLAGS: 00010202 >>> [ 5463.009701] RAX: 0000000000000001 RBX: 0000000000000064 RCX: >>> 0000000000000001 >>> [ 5463.016818] RDX: 0000000000000064 RSI: 0000000000000000 RDI: >>> 0000000000000000 >>> [ 5463.023926] RBP: ffff88007c97fd98 R08: 0000000000000000 R09: >>> ffff88022ffd9d80 >>> [ 5463.031033] R10: 0000000000003189 R11: 0000000000000000 R12: >>> 00000001004ee87e >>> [ 5463.038140] R13: 0000000000000002 R14: 0000000000000000 R15: >>> ffff88022ffd9000 >>> [ 5463.045258] FS: 00007f3e570de740(0000) GS:ffff88022fcc0000(0000) >>> knlGS:0000000000000000 >>> [ 5463.053317] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b >>> [ 5463.059041] CR2: 0000000000000500 CR3: 00000000018dc000 CR4: >>> 00000000000007e0 >>> [ 5463.066157] DR0: 0000000000000000 DR1: 0000000000000000 DR2: >>> 0000000000000000 >>> [ 5463.073276] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: >>> 0000000000000400 >>> [ 5463.080400] Process kswapd3 (pid: 117, threadinfo ffff88007c97e000, >>> task ffff88007c981970) >>> [ 5463.088633] Stack: >>> [ 5463.090646] ffff88007c97fd98 0000000000000000 ffff88007c981970 >>> ffffffff81086080 >>> [ 5463.098090] ffff88007c97fd68 ffff88007c97fd68 ffff88022ffd9d80 >>> 0000000000000002 >>> [ 5463.105527] 0000000000000002 0000000000000000 ffff88007c97feb8 >>> ffffffff8114b0e3 >>> [ 5463.112998] Call Trace: >>> [ 5463.115446] [] ? wake_up_bit+0x40/0x40 >>> [ 5463.120826] [] kswapd+0x6c3/0xa50 >>> [ 5463.125775] [] ? zone_reclaim+0x270/0x270 >>> [ 5463.131415] [] kthread+0xc0/0xd0 >>> [ 5463.136278] [] ? kthread_create_on_node+0x120/0x120 >>> [ 5463.142786] [] ret_from_fork+0x7c/0xb0 >>> [ 5463.148166] [] ? kthread_create_on_node+0x120/0x120 >>> [ 5463.154668] Code: 4e 6d 88 00 48 c7 45 b8 00 00 00 00 48 83 c0 18 48 >>> c7 45 c8 80 60 08 81 48 89 45 d0 48 89 45 d8 8b 04 b5 a0 9a cd 81 85 c0 74 >>> 0f <48> 8b 87 00 05 00 00 a8 04 0f 85 98 00 00 00 e8 b3 c3 >>> [ 5463.174097] RIP [] wait_iff_congested+0x59/0x140 >>> [ 5463.180352] RSP >>> [ 5463.183824] CR2: 0000000000000500 >>> [ 5463.203717] ---[ end trace 9ff4ff9087c13a36 ]--- >>> >>> I attached the config file, hope it can make some help. >> >> Hey Zhouping, >> >> Can you please run with the following commit reverted? >> >> Hillf >> >> commit cda73a10eb3f >> mm: do not sleep in balance_pgdat if there's no i/o congestion > > > Hello Hillf, > > Tested it with cda73a10eb3f reverted on two machines, no such issue occurred > again. It is really good news;) thank you a ton for testing. Hillf -- 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