Re: 2.6.23-rc6-mm1 panic (memory controller issue ?)

[Balbir Singh <balbir@linux.vnet.ibm.com>]

Christoph Lameter wrote:
> On Wed, 19 Sep 2007, Balbir Singh wrote:
> 
>> The fix looks correct, radix_tree_preload() does the same thing in
>> add_to_page_cache(). Thanks for identifying the fix
> 
> Hmmm.... Radix tree preload can only take a limited set of flags?
> 

Yes, the whole code is very interesting. From add_to_page_cache()
we call radix_tree_preload with __GFP_HIGHMEM cleared, but
from __add_to_swap_cache(), we don't make any changes to the
gfp_mask. radix_tree_preload() calls kmem_cache_alloc() and in slub
there is a check

        BUG_ON(flags & GFP_SLAB_BUG_MASK);

So, I guess all our allocations should check against __GFP_DMA and
__GFP_HIGHMEM. I'll review the code, test it and send a fix.

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL