lkml.org 
[lkml]   [2008]   [Jun]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [OOPS] RT kernel on PowerPC

Hi Chirag

On Thu, 19 Jun 2008 18:16:34 +0530 Chirag Jog <chirag@linux.vnet.ibm.com> wrote:

> Hi,
> I was trying out the realtime linux kernel 2.6.25.4-rt3 on a powerpc box.
> The kernel booted fine.
> On running the matrix_mult testcase from the real-time testsuite
> in ltp (ltp/testcases/realtime/func), I get the following Oops.
> After the which machine just freezes.

I do get the same thing on a JS22 blade, and you will find that some other
tests are hanging or oopsing. For example the sbrk_mutex testcase suffers from
missed hrtimer wakeups. I also get loads of:

BUG: using smp_processor_id() in preemptible [00000000] code
all triggered from the sys_munmap -> ... -> free_pgtables code path.

Currently I'm trying to debug some networking problems where the whole
stack gets stuck under heavy receive load.

As you can see, -rt is far from stable on the Power architecture. Sorry for
not having an answer for you but I just wanted to show some of the
obstacles laying ahead.

Sebastien.

> I tried setting the panic_on_oops but that didn't help strangely.
> Also, attached is the config file
>
> Oops: Kernel access of bad area, sig: 11 [#1]
> PREEMPT SMP NR_CPUS=64 NUMA pSeries
> Modules linked in: autofs4 hidp rfcomm l2cap bluetooth sunrpc ehea inet_lro iptable_filter ip_tables xt_tcpudp ip6table_filter ip6_tables x_tables ipv6 dm_mirror dm_multipath dm_mod parport_pc lp parport sg sr_mod ibmvscsic scsi_transport_srp sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd
> NIP: c000000000050fa0 LR: c000000000053db4 CTR: c00000000005ab98
> REGS: c00000009224fe50 TRAP: 0300 Not tainted (2.6.25.4-rt3)
> MSR: 8000000000001032 <ME,IR,DR> CR: 28000088 XER: 00000000
> DAR: c0000180004fc4b0, DSISR: 0000000040000000
> TASK = c000000092200ad0[59] 'events/3' THREAD: c000000092250000 CPU: 3
> GPR00: c0000000004fc480 c0000000922500d0 c0000000005bca00 c000000092200ad0
> GPR04: 0000000000000002 0000000000000038 0000000000000000 000000000000000f
> GPR08: 0000000000000001 c0000180004fc480 0f0f0f0f0f0f0f0f c0000000004d9a00
> GPR12: 8000000000009032 c0000000004fca80 0000000000000000 c000000000413910
> GPR16: 4000000000c00000 c000000000412108 0000000000000000 0000000000284000
> GPR20: c0000000004cb9b0 00000000010cb9b0 0000000000000000 0000001fdaa40b13
> GPR24: 0000000000000000 000000000000001f c0000000922501d0 0000000000000000
> GPR28: 0000000000000001 c000000092200ad0 c00000000056a680 c000000090b18ad0
> NIP [c000000000050fa0] .__resched_task+0x38/0xfc
> LR [c000000000053db4] .try_to_wake_up+0x168/0x200
> Call Trace:
> Instruction dump:
> fbc1fff0 fbe1fff8 ebc2af70 7c7d1b78 f8010010 f821ff71 e81e8008 e97e8000
> e9230008 81290010 79294da4 7d290214 <e8090030> 7c0b002e 7c000074 7800d182
>
> Disassembling the __resched_task,
>
> Dump of assembler code for function __resched_task:
> 0xc000000000050f68 <__resched_task+0>: mflr r0
> 0xc000000000050f6c <__resched_task+4>: std r29,-24(r1)
> 0xc000000000050f70 <__resched_task+8>: std r30,-16(r1)
> 0xc000000000050f74 <__resched_task+12>: std r31,-8(r1)
> 0xc000000000050f78 <__resched_task+16>: ld r30,-20624(r2)
> 0xc000000000050f7c <__resched_task+20>: mr r29,r3
> 0xc000000000050f80 <__resched_task+24>: std r0,16(r1)
> 0xc000000000050f84 <__resched_task+28>: stdu r1,-144(r1)
> 0xc000000000050f88 <__resched_task+32>: ld r0,-32760(r30)
> 0xc000000000050f8c <__resched_task+36>: ld r11,-32768(r30)
> 0xc000000000050f90 <__resched_task+40>: ld r9,8(r3)
> 0xc000000000050f94 <__resched_task+44>: lwz r9,16(r9)
> 0xc000000000050f98 <__resched_task+48>: rldicr r9,r9,9,54
> 0xc000000000050f9c <__resched_task+52>: add r9,r9,r0
> 0xc000000000050fa0 <__resched_task+56>: ld r0,48(r9) <----
> offending instruction
> 0xc000000000050fa4 <__resched_task+60>: lwzx r0,r11,r0
>
>
>
>
>
> --
> Cheers,
> Chirag Jog
>


\
 
 \ /
  Last update: 2008-06-19 15:55    [from the cache]
©2003-2011 Jasper Spaans