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

[John Hubbard <jhubbard@nvidia.com>]

On 3/16/26 6:02 PM, Alexandre Courbot wrote:
> On Tue Mar 17, 2026 at 3:51 AM JST, John Hubbard wrote:
>> On 3/16/26 6:12 AM, Alexandre Courbot wrote:
>>> On Mon Mar 9, 2026 at 10:53 PM JST, Joel Fernandes wrote:
>> ...
>>> 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.
> 
> Not exactly - this patch provides a shortcut for creating an Alignment
> from a u64, but it doesn't allow to store alignments larger than 4GB on
> a 32-bit architecture since the value itself is still stored as a `usize`.
> 
> But that's really a theoretical worry of mine anyway - nobody will ever
> work with buffers larger than 4GB on a 32-bit arch to begin with.

Actually, in the CPU world, this claim was made early and often, but
turned out to be wildly wrong! That's why we have "high mem" in
linux-mm (a constant source of suffering for kernel devs).

The 32-bit systems designer do not feel constrained to keep their
memory sizes below that which they can directly address. :)


thanks,
-- 
John Hubbard