>On Wed, Apr 12, 2023 at 4:38?AM Jaewon Kim <jaewon31.kim@xxxxxxxxxxx> wrote: > >> Yes I think you're right. As a allocator, dma-buf system heap looks to be loose >> in memory allocation. Limiting dmabuf memory may be required. But I think there >> is no nice and reasonable way so far. And the dma-buf system heap is being >> widely used in Android mobile system. AFAIK the camera consumes huge memory >> through this dma-buf system heap. I actually even looked a huge size request >> over 2GB in one dma-buf request. >> >Hey can you point me to where you saw a request that big? That's a >non-buggy request?! (let me resend as plain text) It was one of camera scenarios. I internally asked and heard that was not a bug but normal. I think 2GB looks too big for one graphics buffer but it could be for other purposes like camera. I think the system heap should support that. Regarding __GFP_RETRY_MAYFAIL, we may need to say dma-buf system heap was designed to gather many pages up to a requested size. If mm returns NULL due to __GFP_RETRY_MAYFAIL, dma-buf system heap will release other already allocated pages, so that it may help to avoid oom.
