Re: clang compiled kernel panic when mounting zfs root on i386

on 17/12/2012 14:57 Volodymyr Kostyrko said the following:
> 13.12.2012 12:25, Andriy Gapon:
>> on 12/12/2012 21:35 Dimitry Andric said the following:
>>> Especially the recursive spa_load and traverse_visitbp calls are scary,
>>> because that can grow out of hand very quickly.  It is probably tricky
>>> to remove the recursion...
>>
>> Re-entering spa_load once is normal and is expected.
>> traverse_visitbp is also expected to recurse depending on data layout.
>> So yeah, it's probably even trickier than teaching clang to allocate smaller
>> stack
>> frames ;-)
> 
> I hit this one again, but this time my world and kernel are compiled with stock
> gcc. Pictures 3 to 5:
> 
> https://picasaweb.google.com/104021007361271711472/I386ZfsDoubleFault
> 
> This happens on mounting root after unclean shutdown. I fixed my pool with
> booting amd64 kernel, after this i386 kernel starts fine.
> 
> Maybe it's just time to accept that ZFS on i386 is not stable? Current handbook
> elaborates on ZFS like it's known to work on i386.

Yes, it is known to work.

It's been already mentioned many times that ZFS works much better on amd64.
It's up to a (potential) user to understand limitations of i386 and to decide
whether to use ZFS, in what situations and how.

You may want to consider using KSTACK_PAGES=4 in your kernel configuration.

-- 
Andriy Gapon