On 2022-06-11 10:06, Christian König wrote: > Am 10.06.22 um 16:16 schrieb Michal Hocko: >> [...] >>>> Just consider the above mentioned memcg driven model. It doesn't really >>>> require to chase specific files and do some arbitrary math to share the >>>> responsibility. It has a clear accounting and responsibility model. >>> Ok, how does that work then? >> The memory is accounted to whoever faults that memory in or to the >> allocating context if that is a kernel memory (in most situations). > > That's what I had in mind as well. Problem with this approach is that file descriptors are currently not informed that they are shared between processes. > > So to make this work we would need something like attach/detach to process in struct file_operations. > > And as I noted, this happens rather often. For example a game which renders 120 frames per second needs to transfer 120 buffers per second between client and X. FWIW, in the steady state, the game will cycle between a small (generally 2-5) set of buffers. The game will not cause new buffers to be exported & imported for every frame. In general, I'd expect dma-buf export & import to happen relatively rarely, e.g. when a window is opened or resized. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and Xwayland developer
