Re: 2.6.20: reproducible hard lockup with RAID-5 resync

[Corey Hickey <bugfood-ml@fatooh.org>]

Neil Brown wrote:
>> Ok, so the difference is CONFIG_SYSFS_DEPRECATED. If that is not
>> defined, the kernel locks up. There's not a lot of code under
>> #ifdef/#ifndef CONFIG_SYSFS_DEPRECATED, but since I'm not familiar with
>> any of it I don't expect trying to locate the bug on my own would be
>> very productive.
>>
>> Neil, do you have CONFIG_SYSFS_DEPRECATED enabled? If so, does disabling
>> it reproduce my problem? If you can't reproduce it, should it take the
>> problem over to linux-kernel?
> 
> # CONFIG_SYSFS_DEPRECATED is not set
> 
> No, it is not set, and yet it all still works for me.

Dang, again. :)

> It is very hard to see how this CONFIG option can make a difference.
> Have you double checked that setting it removed the problem and
> clearing it causes the problem?

Yes, it seems odd to me too, but I have double-checked. If I build a
kernel with CONFIG_SYSFS_DEPRECATED enabled, it works; if I disable that
option and rebuild the kernel, it locks up.

I just tried running 'make defconfig' and then enabling only RAID,
RAID-0, RAID-1, and RAID-4/5/6. If I then disable
CONFIG_SYSFS_DEPRECATED, there aren't any problems. ...so, I'll try to
isolate the problem some more later.

Thanks,
Corey