Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [Linaro-mm-sig] [PATCH 08/10] mm: cma: Contiguous Memory Allocator added | Date | Wed, 22 Jun 2011 15:39:23 +0200 |
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On Wednesday 22 June 2011, Marek Szyprowski wrote: > Sounds really good, but it might be really hard to implemnt, at least for > CMA, because it needs to tweak parameters of memory management internal > structures very early, when buddy allocator has not been activated yet.
Why that? I would expect you can do the same that hugepages (used to) do and just attempt high-order allocations. If they succeed, you can add them as a CMA region and free them again, into the movable set of pages, otherwise you just fail the request from user space when the memory is already fragmented.
> > These essentially fight over the same memory (though things are slightly > > different with dynamic hugepages), and they all face the same basic problem > > of getting as much for themselves without starving the other three. > > I'm not sure we can solve all such issues in the first version. Maybe we should > first have each of the above fully working in mainline separately and then > start the integration works.
Yes, makes sense. We just need to be careful not to introduce user-visible interfaces that we cannot change any more in the process.
Arnd
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