Re: [PATCH 2/4] mm: cma: Contiguous Memory Allocator added

["Michał Nazarewicz" <m.nazarewicz@samsung.com>]

On Wed, 21 Jul 2010 15:52:30 +0200, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote:

> On Tue, Jul 20, 2010 at 09:14:58PM +0200, Micha?? Nazarewicz wrote:
>> On Tue, 20 Jul 2010 20:15:24 +0200, Daniel Walker <dwalker@codeaurora.org> wrote:
>
>> > If you have this disconnected from the drivers it will just cause
>> > confusion, since few will know what these parameters should be for a
>> > given driver set. It needs to be embedded in the kernel.
>
>> I see your point but the problem is that devices drivers don't know the
>> rest of the system neither they know what kind of use cases the system
>> should support.
>
> If this does need to be configured per system would having platform data
> of some kind in the kernel not be a sensible a place to do it,

The current version (and the next version I'm working on) of the code
has cma_defaults() call.  It is intended to be called from platform
initialisation code to provide defaults.

> or even
> having a way of configuring this at runtime (after all, the set of
> currently active users may vary depending on the current configuration
> and keeping everything allocated all the time may be wasteful)?

I am currently working on making the whole thing more dynamic.  I imagine
the list of regions would stay pretty much the same after kernel has
started (that's because one cannot reliably allocate new big contiguous
memory regions) but it will be possible to change the set of rules, etc.


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