svn commit: r184146 - in head/sys: amd64/amd64 amd64/include i386/i386 i386/include

[Jung-uk Kim]

On Wednesday 22 October 2008 11:01 am, John Baldwin wrote:
> On Tuesday 21 October 2008 08:01:53 pm Jung-uk Kim wrote:
> > Author: jkim
> > Date: Wed Oct 22 00:01:53 2008
> > New Revision: 184146
> > URL: http://svn.freebsd.org/changeset/base/184146
> >
> > Log:
> >   Set kern.timecounter.invariant_tsc to 1 for AMD CPU family 10h
> > and higher even if BIOS does not advertise it.
> >
> > Modified:
> >   head/sys/amd64/amd64/identcpu.c
> >   head/sys/amd64/include/specialreg.h
> >   head/sys/i386/i386/identcpu.c
> >   head/sys/i386/include/specialreg.h
> >
> > Modified: head/sys/amd64/amd64/identcpu.c
>
> ===================================================================
>===========
>
> > --- head/sys/amd64/amd64/identcpu.c	Tue Oct 21 23:36:28
> > 2008	(r184145) +++ head/sys/amd64/amd64/identcpu.c	Wed Oct 22
> > 00:01:53 2008	(r184146) @@ -348,7 +348,9 @@ printcpuinfo(void)
> >  				cpu_feature &= ~CPUID_HTT;
> >
> >  			if (!tsc_is_invariant &&
> > -			    (amd_pminfo & AMDPM_TSC_INVARIANT)) {
> > +			    (strcmp(cpu_vendor, "AuthenticAMD") == 0 &&
> > +			    ((amd_pminfo & AMDPM_TSC_INVARIANT) != 0 ||
> > +			    AMD64_CPU_FAMILY(cpu_id) >= 0x10))) {
> >  				tsc_is_invariant = 1;
> >  				printf("\n  P-state invariant TSC");
> >  			}
>
> Perhaps a simpler approach might be to just set AMDPM_TSC_INVARIANT
> for AMD64_CPU_FAMILY(cpu_id) >= 0x10?

It seems Athlon X2 (Family 0Fh, Model 6Bh, Stepping G2) that I bought 
also has invariant TSC although it is not advertised by CPUID.  If 
BIOS manufacturer decide to set the bit later, it should be honored 
IMO.

Jung-uk Kim