Re: in 2.6.23-rc3-git7 in do_cciss_intr

[Randy Dunlap <randy.dunlap@oracle.com>]

Jens Axboe wrote:
> On Thu, Sep 04 2008, Miller, Mike (OS Dev) wrote:
>>>>>> 0x3bb2 <do_cciss_intr+1649>:    mov    0x2(%r8),%dx
>>>>>> 0x3bb7 <do_cciss_intr+1654>:    test   %dx,%dx
>>>>>> 0x3bba <do_cciss_intr+1657>:    je     0x3f0e <do_cciss_intr+2509>
>>>>>>
>>>>>>
>>>>>> $ addr2line -e cciss.o -f  do_cciss_intr+0x627 SA5_fifo_full
>>>>>>
>>> /home/rdunlap/linsrc/linux-2.6.27-rc3-git7/drivers/block/cciss.h:206
>>>>> OK ...that's confusing.  It seems to be saying that ctrlr_info_t *
>>>>> was NULL.  However, I can't see a way of getting into the
>>> fifo_full
>>>>> callback from do_cciss_intr ..
>>>>> especially not with an NULL host.
>>>>>
>>>>> James
>>>> That is weird. Even if we could get there fifo_full doesn't
>>> do anything but wait for a bit.
>>>
>>> Hi,
>>>
>>> This just happened again.  This time it's on 2.6.27-rc5-git3.
>>>
>>> ~Randy
>> Thanks Randy. I think. :)
>>
>> I'll try to recreate in my lab.
> 
> This looks somewhat strange, mostly like 'c' is NULL and it's oopsing in
> in removeQ (I don't think Randy's analysis is correct in assuming it's
> 'h' and it's in fifo_full). Given that 'c' cannot be NULL, it's c->prev
> or c->next that are NULL.

Yes, correct IMO.  I checked my daily test logs and I have had this problem
in do_cciss_intr() 3 times, all at the same location, which appears to be
in removeQ(), as Jens says.


-- 
~Randy