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no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: linux-kernel@vger.kernel.org, Miguel Ojeda , Boqun Feng , Gary Guo , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Dave Airlie , dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, rust-for-linux@vger.kernel.org, Alexandre Courbot , arunpravin.paneerselvam@amd.com, joel@joelfernandes.org X-Mailman-Version: 3.3.8 Precedence: list List-Id: Nouveau development list Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Hi Danilo, On Fri, Feb 27, 2026 at 12:30:20PM +0100, Danilo Krummrich wrote: > > > > +RUST [GPU BUDDY] > > +M: Joel Fernandes > > +L: dri-devel@lists.freedesktop.org > > +L: rust-for-linux@vger.kernel.org > > +S: Maintained > > +F: rust/helpers/gpu.c > > +F: rust/kernel/gpu/ > > What about adding this to the existing GPU BUDDY ALLOCATOR entry? Maybe you can > offer Matthew and Arun your help. > > Also, this wouldn't be a subentry of "RUST", but the rust version of GPU BUDDY, > so it would be "GPU BUDDY [RUST]". > > Also, please add rust/kernel/gpu/ to the "DRM DRIVERS AND COMMON INFRASTRUCTURE > [RUST]" entry. Both these additions sound good to me. Just to list all the options below so we save time on what we all agree on: 1. New GPU BUDDY [RUST] entry. 2. Add it under the existing "DRM DRIVERS AND COMMON INFRASTRUCTURE [RUST]" 3. Add the rust files under the existing "GPU BUDDY ALLOCATOR" and add myself and Alex as R:/M: Which of these options make sense? Personally, I think #2 makes sense since we are already suggesting to add it to the existing DRM RUST entry anyway - we can just drop the new record and add rust/helpers/gpu.c there as well. That's what I've done for now. Does that work for you/others? > > +/// # Invariants > > +/// > > +/// The inner [`Opaque`] contains a valid, initialized buddy allocator. > > The invariant should be justified in the constructor. Also, where is it used? Done. Added `// INVARIANT:` justification in `GpuBuddyInner::new()` and cited at all usage sites (ex, alloc_blocks). > > +// SAFETY: GpuBuddyInner is `Sync` because the internal GpuBuddyGuard > > +// serializes all access to the C allocator, preventing data races. > > I think it's more precise to refer to GpuBuddyInner::lock. Agreed. Fixed to reference `GpuBuddyInner::lock`. > > +/// # Invariants > > +/// > > +/// The inner [`Arc`] points to a valid, initialized GPU buddy allocator. > > Do we need this invariant? Isn't this implied by the GpuBuddyInner type? Right, removed. > > + // SAFETY: list contains gpu_buddy_block items linked via __bindgen_anon_1.link. > > + let clist = clist_create!(unsafe { > > This macro has three separate safety requirements, please justify all of them. > Also, please also use markdown in safety comments. Done. Expanded to justify all three safety requirements. > > +pub struct Block(Opaque); > > Does this need to be public? I don't see it being exposed by any API. You're right. Made it private. > > +/// An allocated block with access to the GPU buddy allocator. > > This needs a better description, i.e. what makes an `AllocatedBlock different > compared to a "normal" Block. Updated to the following: /// A [`Block`] paired with its owning [`AllocatedBlocks`] context. /// /// Unlike a raw [`Block`], which only knows its offset within the buddy address /// space, an [`AllocatedBlock`] also has access to the allocator's /// `base_offset` and `chunk_size`, enabling it to compute absolute offsets and /// byte sizes. /// /// Returned by [`AllocatedBlocks::iter()`]. pub struct AllocatedBlock<'a> { this: &'a Block, blocks: &'a AllocatedBlocks, } > > +/// - `block` is a valid reference to an allocated [`Block`]. > > +/// - `alloc` is a valid reference to the [`AllocatedBlocks`] that owns this block. > > References should always be valid, no need to mention that. Removed. > > + block: &'a Block, > > NIT: What about just naming it "this" and > > > + alloc: &'a AllocatedBlocks, > > "blocks"? Done, that's better. thanks, -- Joel Fernandes