Re: [PATCH 01/31] gpu: nova-core: print FB sizes, along with ranges

[John Hubbard]

On 12/3/25 11:35 AM, Timur Tabi wrote:
> On Tue, 2025-12-02 at 21:58 -0800, John Hubbard wrote:
> > +impl fmt::Debug for FbRange {
> > +    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
> > +        let size_mb = (self.0.end - self.0.start) >> 20;
> > +        f.write_fmt(fmt!(
> > +            "{:#x}..{:#x} ({} MB)",
> > +            self.0.start,
> > +            self.0.end,
> > +            size_mb
> > +        ))
> > +    }
> > +}
> > +
>
> How about printing size_kb if size_mb == 0 or if it's not an even multiple of MB?

Good idea, I'll do that.

> Also, why not just add this function to Range<> instead of creating a new type?

Rust's orphan rules prevent implementing a foreign trait (Debug) on a
foreign type (Range<u64>). Both are defined in core, not in nova-core,
so the compiler won't allow it. The newtype pattern is the standard Rust
workaround for this: by wrapping Range<u64> in a local type FbRange, we
can implement whatever traits we need.

thanks,
--
John Hubbard