Re: [PATCH v12.1 1/1] rust: gpu: Add GPU buddy allocator bindings

[John Hubbard <jhubbard@nvidia.com>]

On 3/16/26 6:12 AM, Alexandre Courbot wrote:
> On Mon Mar 9, 2026 at 10:53 PM JST, Joel Fernandes wrote:
...
>> +//! // Create a 1GB buddy allocator with 4KB minimum chunk size.
>> +//! let buddy = GpuBuddy::new(GpuBuddyParams {
>> +//!     base_offset: 0,
>> +//!     physical_memory_size: SZ_1G as u64,
>> +//!     chunk_size: SZ_4K,
> 
> `chunk_size` is an interesting case. The C API uses a `u64`, but I think
> we can reasonably consider that we won't ever need chunks larger than
> 4GB (or can we :O). I'm actually ok with using a `usize` for this one.
> 
> One of the first things the C code does is throwing an error if it is
> not a power of 2, so maybe we can even request an `Alignment`?
> 
> I'm a bit torn as to whether we should use a `u64` to conform with the C
> API, but doing so would mean we cannot use an `Alignment`...

Alex, have you seen my Alignment patch [1], for that? It's sitting 
around with only Miguel having responded, but seems like exactly
what you're talking about here.

[1] https://lore.kernel.org/20260312031507.216709-3-jhubbard@nvidia.com

thanks,
-- 
John Hubbard