On Wed, 2011-08-17 at 15:06 +0200, Marek Szyprowski wrote: [...]
Maybe for the first version a static pool with reasonably small size (like 128KiB) will be more than enough? This size can be even board depended or changed with kernel command line for systems that really needs more memory.
For a first version that sounds good enough. Maybe we could use a fraction of the CONSISTENT_DMA_SIZE as an estimate?
Ok, good. For the initial values I will probably use 1/8 of CONSISTENT_DMA_SIZE for coherent allocations. Writecombine atomic allocations are extremely rare and rather ARM specific. 1/32 of CONSISTENT_DMA_SIZE should be more than enough for them.
For people who aren't aware, we have a patch to remove the define CONSISTENT_DMA_SIZE and replace it with a runtime call to an initialisation function [1]. I don't believe this fundamentally changes anything being discussed though.