On 03/03/2017 08:25 AM, Laurent Pinchart wrote:
Hi Laura,
Thank you for the patches.
On Thursday 02 Mar 2017 13:44:32 Laura Abbott wrote:
Hi,
There's been some recent discussions[1] about Ion-like frameworks. There's apparently interest in just keeping Ion since it works reasonablly well. This series does what should be the final clean ups for it to possibly be moved out of staging.
This includes the following:
- Some general clean up and removal of features that never got a lot of use as far as I can tell.
- Fixing up the caching. This is the series I proposed back in December[2] but never heard any feedback on. It will certainly break existing applications that rely on the implicit caching. I'd rather make an effort to move to a model that isn't going directly against the establishement though.
- Fixing up the platform support. The devicetree approach was never well recieved by DT maintainers. The proposal here is to think of Ion less as specifying requirements and more of a framework for exposing memory to userspace.
That's where most of my concerns with ion are. I still strongly believe that the heap-based approach is inherently flawed, as it would need to be configured for each device according to product-specific use cases. That's not something that could be easily shipped with a generic distribution. We should replace that with a constraint-based system.
I don't think of constraints and heaps as being mutually exclusive. Some general heaps (e.g. system heaps) can be available always. Others might just be exposed if there is a particular memory region available. The constraint solving is responsible for querying and figuring out what's the best choice.
Thanks, Laura