Re: [patch 7/8] slub: Make the order configurable for each slab cache

[Pekka Enberg <penberg@cs.helsinki.fi>]

Christoph Lameter wrote:
> On Sat, 1 Mar 2008, Pekka Enberg wrote:
> 
>> I am not sure I understand what you mean here. For example, for a
>> cache that requires minimum order of 1 to fit any objects (which
>> doesn't happen now because of page allocator pass-through), the
>> order_store() function can call calculate_sizes() with forced_order
> 
> It does happen because the page allocator pass through is only possible 
> for kmalloc allocations.
> 
>> set to zero after which the cache becomes useless. That deserves a
>> code comment, I think.
> 
> If the object does not fit into a page then calculate_sizes will violate 
> max_order (if necessary) in order to make sure that an allocation is 
> possible.

Hmm, I seem to be missing something here. For page size of 4KB, object 
size of 8KB, and min_order of zero, when I write zero order to 
/sys/kernel/slab/<cache>/order the kernel won't crash because...?

			Pekka

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