Re: [PATCH v1 1/2] vsprintf: Add %pR human-readable size

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Aug 08, 2026 at 08:43:30PM +0300, Andy Shevchenko wrote:
> On Sat, Aug 08, 2026 at 12:23:07PM -0500, Bjorn Helgaas wrote:
> > Include human-readable size when printing struct resource memory ranges
> > (not including DMA, bus number, or I/O port ranges) with the %pR format to
> > make it easier to read, e.g.,
> > 
> >   - pci 0000:00:02.0: BAR 0 [mem 0xfea80000-0xfea9ffff]
> >   + pci 0000:00:02.0: BAR 0 [mem 0xfea80000-0xfea9ffff (128 KiB)]
> 
> ...
> 
> >  lib/vsprintf.c | 18 ++++++++++++++----
> >  1 file changed, 14 insertions(+), 4 deletions(-)
> 
> Sorry, we do not accept this without added test cases.

TIL about these tests, they look great and I'll fix this up and update
printk-formats.rst as well, thank you!

> ...
> 
> > +	if (res->flags & IORESOURCE_MEM) {
> 
> Besides we have resource_type() macro, why only this? I would expect
> IO as well as 64-bit MEM version.

We could use resource_type() here, but would have to check other bits
directly (IORESOURCE_PREFETCH, IORESOURCE_MEM_64, etc) since they're
not included.

I considered including IO and certainly could do that.  IO resources
are smaller and it's not as interesting, but maybe we should.

64-bit MEM resources are already included because they have both
IORESOURCE_MEM and IORESOURCE_MEM_64 set.

> > +		*p++ = ' ';
> > +		*p++ = '(';
> > +		string_get_size(resource_size(res), 1, STRING_UNITS_2,
> > +				size_buf, sizeof(size_buf));
> 
> > +		p = string_nocheck(p, pend, size_buf, str_spec);
> 
> Why do you need this? Use returned value from string_get_size() directly.

string_get_size() doesn't return a char * like string_nocheck() et al
do.  We could do something like "p += string_get_size(..., p, pend - p)",
but it's a little messy because the return value is the length that
*would* have been written if it was truncated, so I think we'd have to
check for "p > pend".  I'll ponder this one.

> > +		*p++ = ')';
> > +	}
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
>