RE: [PATCH 0/3] hwmem: Hardware memory driver

Johan MOSSBERG
2010-11-16T15:25:32Z

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MichaÅ‚ Nazarewicz wrote:
> In particular, I'll try to figure out what you mean by defragmentation
> and see whethe it could be added to CMA.

I mean the ability to move allocated buffers to free more
contiguous space. To support this in CMA the API(s) would have to
change.
* A buffer's physical address cannot be used to identify it as the
physical address can change.
* Pin/unpin functions would have to be added so that you can pin a
buffer when hardware uses it.
* The allocators needs to be able to inform CMA that they have
moved a buffer. This is so that CMA can keep track of what memory
is free so that it can supply the free memory to the kernel for
temporary use there.

/Johan Mossberg
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