Re: [PATCH v3 3/4] x86/efi: print size in binary units in efi_print_memmap

From: Matt Fleming
Date: Thu Jan 28 2016 - 04:30:15 EST


On Tue, 26 Jan, at 01:59:26PM, Andy Shevchenko wrote:
> On Tue, 2016-01-26 at 11:50 +0000, Matt Fleming wrote:
> > On Mon, 25 Jan, at 08:37:58PM, Elliott, Robert (Persistent Memory)
> > wrote:
> > >
> > > For the UEFI memory map, that was indeed my intention.  I
> > > don't want it silently round to "20 GiB".  Even rounding
> > > to "19.999 GiB" is imprecise.
> >
> > OK, let's just go with your original patch Robert (minus the @ addr
> > bit) since it's pretty small and does what we want for this specific
> > case.
>
> However I am against this, but seems reviewers do not leave a chance to
> us, I would propose to copy-and-paste table of binary prefixes and use
> __ffs64().

Is there a benefit to this approach other than __ffs64() being faster?
It is a neglibible performance gain anyway because this is hidden
behind efi=debug, and so by definition you're not looking for ultra
performance.

Which makes picking between __ffs64() and non-__ffs64() a wash if
we're not going to be reusing existing code.