On Wed, Apr 14, 2021 at 08:45:51PM +0200, ojeda@xxxxxxxxxx wrote: > - Manish Goregaokar implemented the fallible `Box`, `Arc`, and `Rc` > allocator APIs in Rust's `alloc` standard library for us. There's a philosophical point to be discussed here which you're skating right over! Should rust-in-the-linux-kernel provide the same memory allocation APIs as the rust-standard-library, or should it provide a Rusty API to the standard-linux-memory-allocation APIs? You seem to be doing both ... there was a wrapper around alloc_pages() in the Binder patches, and then you talk about Box, Arc and Rc here. Maybe there's some details about when one can use one kind of API and when to use another. But I fear that we'll have Rust code at interrupt level trying to use allocators which assume that they can sleep, and things will go badly wrong. By the way, I don't think that Rust necessarily has to conform to the current way that Linux works. If this prompted us to track the current context (inside spinlock, handling interrupt, performing writeback, etc) and do away with (some) GFP flags, that's not the end of the world. We're already moving in that direction to a certain extent with the scoped memory allocation APIs to replace GFP_NOFS / GFP_NOIO.
