AW: UBI leb_write_unlock NULL pointer Oops (continuation)

[Wiedemer, Thorsten (Lawo AG)]

Hi,

> -----Ursprüngliche Nachricht-----
> Von: Richard Weinberger [mailto:richard at nod.at] 
> Gesendet: Mittwoch, 5. Februar 2014 09:29
> An: Wiedemer, Thorsten (Lawo AG)
> Cc: linux-mtd at lists.infradead.org; Bill Pringlemeir
> Betreff: Re: UBI leb_write_unlock NULL pointer Oops (continuation) 
>
> Am 04.02.2014 18:01, schrieb Wiedemer, Thorsten (Lawo AG):
>>  Hi,
>>  
>>  I made a "hardcore test" with:
>>  $ while [ 1 ]; do cp <file_of_8kByte_size> 
>>  tmp/<file_of_8kByte_size.1>; sync; done & $ while [ 1 ]; do cp 
>>  <file_of_8kByte_size> tmp/<file_of_8kByte_size.2>; sync; done & $ 
>>  while [ 1 ]; do cp <file_of_8kByte_size> tmp/<file_of_8kByte_size.3>; 
>>  sync; done &
>>  
>>  It took about 2-3 hours until I had an error (two times):
>
> This test ran the over night without any error on my imx51 board. :-\
>
> Bill's great analysis showed that it may be a linked list corruption in rw_semaphore.
> Thorsten, can you please enable CONFIG_DEBUG_LIST?
> Also try whether you can trigger the issue with lock debugging enabled.
>
> Thanks,
> //richard

short update (I was out of office the rest of last week).
I compiled the kernel with the debug flags for debug list and lock alloc.
The kernel compiled with gcc-4.8.2 didn't start (no output on serial console and reboot of the system).
I didn't try (yet) to find out what happens at startup.

I compiled the same kernel (and same config) with gcc-4.4.4. The write test runs now for over 16 hours without error.
Next step is to find out wether this is due to a changed timing because of the debug flags or if it's the compiler.

Best regards,
Thorsten