[PATCHv8 00/12] Contiguous Memory Allocator

Michal Nazarewicz mina86 at mina86.com
Thu Dec 23 08:41:26 EST 2010


Russell King - ARM Linux <linux at arm.linux.org.uk> writes:
> Has anyone addressed my issue with it that this is wide-open for
> abuse by allocating large chunks of memory, and then remapping
> them in some way with different attributes, thereby violating the
> ARM architecture specification?
>
> In other words, do we _actually_ have a use for this which doesn't
> involve doing something like allocating 32MB of memory from it,
> remapping it so that it's DMA coherent, and then performing DMA
> on the resulting buffer?

Huge pages.

Also, don't treat it as coherent memory and just flush/clear/invalidate
cache before and after each DMA transaction.  I never understood what's
wrong with that approach.

-- 
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