On 04/16/2013 03:50 PM, Heiko Carstens wrote:
> On Mon, Apr 15, 2013 at 02:16:55PM +0800, Zhouping Liu wrote:
>> On 04/15/2013 01:56 PM, Heiko Carstens wrote:
>>> On Sun, Apr 14, 2013 at 11:28:40PM -0400, Zhouping Liu wrote:
>>>> � 16109.346170¨ Call Trace:
>>>> � 16109.346179¨ (� <0000000000100920>¨ show_trace+0x128/0x12c)
>>>> � 16109.346195¨  � <00000000001cd320>¨ rcu_check_callbacks+0x458/0xccc
>>>> � 16109.346209¨  � <0000000000140f2e>¨ update_process_times+0x4a/0x74
>>>> � 16109.346222¨  � <0000000000199452>¨ tick_sched_handle.isra.12+0x5e/0x70
>>>> � 16109.346235¨  � <00000000001995aa>¨ tick_sched_timer+0x6a/0x98
>>>> � 16109.346247¨  � <000000000015c1ea>¨ __run_hrtimer+0x8e/0x200
>>>> � 16109.346381¨  � <000000000015d1b2>¨ hrtimer_interrupt+0x212/0x2b0
>>>> � 16109.346385¨  � <00000000001040f6>¨ clock_comparator_work+0x4a/0x54
>>>> � 16109.346390¨  � <000000000010d658>¨ do_extint+0x158/0x15c
>>>> � 16109.346396¨  � <000000000062aa24>¨ ext_skip+0x38/0x3c
>>>> � 16109.346404¨  � <00000000001153c8>¨ smp_yield_cpu+0x44/0x48
>>>> � 16109.346412¨ (� <000003d10051aec0>¨ 0x3d10051aec0)
>>>> � 16109.346457¨  � <000000000024206a>¨ __page_check_address+0x16a/0x170
>>>> � 16109.346466¨  � <00000000002423a2>¨ page_referenced_one+0x3e/0xa0
>>>> � 16109.346501¨  � <000000000024427c>¨ page_referenced+0x32c/0x41c
>>>> � 16109.346510¨  � <000000000021b1dc>¨ shrink_page_list+0x380/0xb9c
>>>> � 16109.346521¨  � <000000000021c0a6>¨ shrink_inactive_list+0x1c6/0x56c
>>>> � 16109.346532¨  � <000000000021c69e>¨ shrink_lruvec+0x252/0x56c
>>>> � 16109.346542¨  � <000000000021ca44>¨ shrink_zone+0x8c/0x1bc
>>>> � 16109.346553¨  � <000000000021d080>¨ balance_pgdat+0x50c/0x658
>>>> � 16109.346564¨  � <000000000021d318>¨ kswapd+0x14c/0x470
>>>> � 16109.346576¨  � <0000000000158292>¨ kthread+0xda/0xe4
>>>> � 16109.346656¨  � <000000000062a5de>¨ kernel_thread_starter+0x6/0xc
>>>> � 16109.346682¨  � <000000000062a5d8>¨ kernel_thread_starter+0x0/0xc
>>>> [-- MARK -- Fri Apr 12 06:15:00 2013]
>>>> � 16289.386061¨ INFO: rcu_sched self-detected stall on CPU { 0}  (t=42010 jiffies
>>>>   g=89766 c=89765 q=10627)
>>> Did the system really crash or did you just see the rcu related warning(s)?
>> I just check it again, actually at first the system didn't really
>> crash, but the system is very slow in response.
>> and the reproducer process can't be killed, after I did some common
>> actions such as 'ls' 'vim' etc, the system
>> seemed to be really crashed, no any response.
>>
>> also in the previous testing, I can remember that the system would
>> be no any response for a long time, just only
>> repeatedly print out the such above 'Call Trace' into console.
> Ok, thanks.
> Just a couple of more questions: did you see this also on other archs, or just
> s390 (if you tried other platforms at all).

Didn't meet the issue on other arches, just only on s390x, I will check 
further on other arches.

>
> If you have some time, could you please repeat your test with the kernel
> command line option " user_mode=home "?

Sure, but the testing machine is not in my hand now, I will test it ASAP 
when I get it, also I'll
try it on other s390x machine.

>
> As far as I can tell there was only one s390 patch merged that was
> mmap related: 486c0a0bc80d370471b21662bf03f04fbb37cdc6 "s390/mm: Fix crst
> upgrade of mmap with MAP_FIXED".
> Even though I don't think it explains the bug you've seen it might be worth
> to try to revert it.

OK, I'll try it later.

>
> And at last, can you share your kernel config?

Of course.

Thanks,
Zhouping

>
> Thanks,
> Heiko
>