svn commit: r314669 - head/sys/i386/conf

[John Baldwin]

On Saturday, March 04, 2017 03:49:52 PM Pedro Giffuni wrote:
> 
> > Il giorno 04 mar 2017, alle ore 14:43, John Baldwin <jhb at freebsd.org> ha scritto:
> > 
> > On Saturday, March 04, 2017 10:52:46 AM Pedro Giffuni wrote:
> >> 
> >> On 03/04/17 10:32, Slawa Olhovchenkov wrote:
> >>> On Sat, Mar 04, 2017 at 03:04:17PM +0000, Pedro F. Giffuni wrote:
> >>> 
> >>>> Author: pfg
> >>>> Date: Sat Mar  4 15:04:17 2017
> >>>> New Revision: 314669
> >>>> URL: https://svnweb.freebsd.org/changeset/base/314669
> >>>> 
> >>>> Log:
> >>>>  Drop i486 from the default i386 GENERIC kernel configuration.
> >>>> 
> >>>>  80486 production was stopped by Intel on September 2007. Dropping the 486
> >>>>  configuration option from the GENERIC kernel improves performance
> >>>>  slightly.
> >>>> 
> >>>>  Removing I486_CPU is consistent at this time: we don't support any
> >>>>  processor without a FPU and the PC-98 arch, which frequently involved i486
> >>>>  CPUs, is also gone so we don't test such platforms anymore.
> >>> 
> >>> What is realy mean?
> >> 
> >> This means we don't do work-arounds that would be required for raw 486.
> >> Instead we will use the 586 instructions by default.
> > 
> > This doesn't change that.  The kernel already has runtime tests in place
> > for new things on 486 and later via cpuid.
> > 
> 
> Hmm ..then I am wondering if I effectively changed anything?

The only change is a 486 now panics on boot when it used to work fine. :-/

Nothing for other CPUs has changed.
 
> The number came out from an old posting involving buildworld times, which I can’t find now :(.
> Things seem to have changed a lot: it was surely using GCC back then, I don’t believe clang does much distinction about 486 at all.
> 
> BTW, does it make sense to keep i586 in the configuration still? Both i486 and i586 were once removed but later re-instated in r205336.

If anything I'd probably say we should do what bde@ suggested and just
remove CPU class entirely (and act as if 486, 586, and 686 are always
defined).

-- 
John Baldwin