On Wed, 8 May 2024 at 09:33, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Wed, May 08, 2024 at 06:46:53AM +0100, Daniel Stone wrote: > > That would have the unfortunate side effect of making sandboxed apps > > less efficient on some platforms, since they wouldn't be able to do > > direct scanout anymore ... > > I was assuming that everyone goes through pipewire, and ideally that is > the only one that can even get at these special chardev. > > If pipewire is only for sandboxed apps then yeah this aint great :-/ No, PipeWire is fine, I mean graphical apps. Right now, if your platform requires CMA for display, then the app needs access to the GPU render node and the display node too, in order to allocate buffers which the compositor can scan out directly. If it only has access to the render nodes and not the display node, it won't be able to allocate correctly, so its content will need a composition pass, i.e. performance penalty for sandboxing. But if it can allocate correctly, then hey, it can exhaust CMA just like heaps can. Personally I think we'd be better off just allowing access and figuring out cgroups later. It's not like the OOM story is great generally, and hey, you can get there with just render nodes ... Cheers, Daniel
