Subject: Re: [BUG] 2.6.24-rc3-mm2 soft lockup while running tbench

From: Kamalesh Babulal <[email-masked]>
Date: Fri, 30 Nov 2007 10:39:15 +0530

Andrew Morton wrote:
> On Wed, 28 Nov 2007 20:03:22 +0530
> Kamalesh Babulal <[email-masked]> wrote:
> 
>> Hi Andrew,
>>
>> while running tbench on the powerpc with 2.6.24-rc3-mm2 softlock up occurs
>>
>> BUG: soft lockup - CPU#0 stuck for 11s! [tbench:12183]
>> NIP: c0000000000ac978 LR: c0000000000acff0 CTR: c00000000005c648
>> REGS: C00000076F0F3200 TRAP: 0901   Not tainted  (2.6.24-rc3-mm2-autotest)
>> MSR: 8000000000009032 <EE,ME,IR,DR>  CR: 44000482  XER: 00000000
>> TASK = C00000076F4BC000[12183] 'tbench' THREAD: C00000076F0F0000 CPU: 0
>> NIP [c0000000000ac978] .get_page_from_freelist+0x1cc/0x754
>> LR [c0000000000acff0] .__alloc_pages+0xb0/0x3a8
>> Call Trace:
>> [c00000076f0f3480] [c00000076f0f3560] 0xc00000076f0f3560 (unreliable)
>> [c00000076f0f3590] [c0000000000acff0] .__alloc_pages+0xb0/0x3a8
>> [c00000076f0f3680] [c0000000000ce2e4] .alloc_pages_current+0xa8/0xc8
>> [c00000076f0f3710] [c0000000000ac6ec] .__get_free_pages+0x20/0x70
>> [c00000076f0f3790] [c0000000000d75c8] .__kmalloc_node_track_caller+0x60/0x148
>> [c00000076f0f3840] [c0000000002c22b0] .__alloc_skb+0x98/0x184
>> [c00000076f0f38f0] [c000000000306cd8] .tcp_sendmsg+0x1fc/0xe24
>> [c00000076f0f3a10] [c0000000002b963c] .sock_sendmsg+0xe4/0x128
>> [c00000076f0f3c10] [c0000000002ba4ec] .sys_sendto+0xd4/0x120
>> [c00000076f0f3d90] [c0000000002df2f8] .compat_sys_socketcall+0x148/0x214
>> [c00000076f0f3e30] [c00000000000872c] syscall_exit+0x0/0x40
>> Instruction dump:
>> 720b0001 eb970000 40820070 72000002 4182000c e8bc0000 48000018 72080004 
>> 4182000c e8bc0008 48000008 e8bc0010 <e8c10078> 7f83e378 7de407b4 7e078378 
>>
> 
> hm.  Beats me.  Does the machine recover OK?
> -
Hi Andrew,

In the set of test cases ran serially, the softlockup in seen in tbench,
then the remaining test cases get to run successfully after the softlockup.

-- 
Thanks & Regards,
Kamalesh Babulal,
Linux Technology Center,
IBM, ISTL.