Re: [PATCH] nommu page refcount bug fixing

From: Nick Piggin
Date: Thu Mar 30 2006 - 14:02:31 EST


Luke Yang wrote:
NOMMU special-casing in page refcounting. As a temporary fix, what I
think should happen is simply for all slab allocations to ask for
__GFP_COMP pages.

Could you check that fixes your problem?

It works. What's your plan to modify nommu mm? I would like to
help. And I am also interested in implementing the "non-power-of-2"
allocator in 2.6.


I'll get it up to date and send it over to you, offline. It
would be great if you could help.

New patch:


Acked-by: Nick Piggin <npiggin@xxxxxxx>

I'll write a changelog for you:

***
The earlier patch to consolidate mmu and nommu page allocation
and refcounting by using compound pages for nommu allocations
had a bug: kmalloc slabs who's pages were initially allocated
by a non-__GFP_COMP allocator could be passed into mm/nommu.c
kmalloc allocations which really wanted __GFP_COMP underlying
pages.

Fix that by having nommu pass __GFP_COMP to all higher order
slab allocations
***

Sound OK? Can you do it next time? ;)

--
SUSE Labs, Novell Inc.
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