Re: [RESEND][PATCH v8 0/5] DMA-BUF Heaps (destaging ION)

[Andrew F. Davis]

On 10/14/19 5:07 AM, Brian Starkey wrote:
> Hi Andrew,
> 
> On Wed, Oct 09, 2019 at 02:27:15PM -0400, Andrew F. Davis wrote:
>> The CMA driver that registers these nodes will have to be expanded to
>> export them using this framework as needed. We do something similar to
>> export SRAM nodes:
>>
>> https://lkml.org/lkml/2019/3/21/575
>>
>> Unlike the system/default-cma driver which can be centralized in the
>> tree, these extra exporters will probably live out in other subsystems
>> and so are added in later steps.
>>
>> Andrew
> 
> I was under the impression that the "cma_for_each_area" loop in patch
> 4 would do that (add_cma_heaps). Is it not the case?
> 

For these cma nodes yes, I thought you meant reserved memory areas in
general.

Just as a side note, I'm not a huge fan of the cma_for_each_area() to
begin with, it seems a bit out of place when they could be selectively
added as heaps as needed. Not sure how that will work with cma nodes
specifically assigned to devices, seems like we could just steal their
memory space from userspace with this..

Andrew

> Thanks,
> -Brian
>