Re: [RFC v2] percpu: Add a separate function to merge free areas

From: Tejun Heo
Date: Thu Dec 04 2014 - 15:45:43 EST


Hello, Christoph.

On Thu, Dec 04, 2014 at 02:28:10PM -0600, Christoph Lameter wrote:
> Well this is not a common use case and that is not what the per cpu
> allocator was designed for. There is bound to be signifcant fragmentation
> with the current design. The design was for rare allocations when
> structures are initialized.

My unverified gut feeling is that fragmentation prolly is a lot less
of a problem for percpu allocator given that most percpu allocations
are fairly small. On the other hand, we do wanna pack them tight as
percpu memory is really expensive space-wise. I could be wrong tho.

Thanks.

--
tejun
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