Re: [PATCH next] i386: Remove string functions that use 'rep scasb'

[Maciej W. Rozycki]

On Mon, 30 Mar 2026, Dave Hansen wrote:

> > I have Intel Quark at hand to test. But I need to know the
> > step-by-step instructions on what to do.
> 
> I'll take it if it's all that we have, but Quark is really weird. It's
> probably Intel's last sold 32-bit-only CPU, but it wasn't used for
> anything remotely performance sensitive, it's more like a 1995 CPU than
> a 2010 CPU, and Intel probably sold like twenty of them. ;)
> 
> But, seriously, we don't need to go digging in the junk heap for
> performance numbers. If nobody has one handy, it's just extra
> justification for "we don't care".
> 
> But let's just say *THAT* instead of doing some kind of performance
> theater where we pretend that like every cycle on CPUs from 2003 matters
> on a 2026 kernel, and that we even cared enough to measure it.

 FWIW I can benchmark on a genuine i486 or Pentium MMX system right away, 
but I'm more concerned about support being dropped altogether rather than 
squeezing out any extra cycles from these boxes at this point.  If anyone 
runs such equipment for performance nowadays, they must clearly be mad or 
have missed something.

  Maciej