cvs commit: src/sys/amd64/amd64 identcpu.c src/sys/i386/i386 identcpu.c

[Jung-uk Kim]

On Monday 17 October 2005 02:31 pm, David O'Brien wrote:
> On Mon, Oct 17, 2005 at 02:17:33PM -0400, Jung-uk Kim wrote:
> > On Monday 17 October 2005 01:28 pm, David O'Brien wrote:
> > > On Mon, Oct 17, 2005 at 12:00:47PM -0400, Jung-uk Kim wrote:
> > > > On Sunday 16 October 2005 04:58 am, David E. O'Brien wrote:
> > > > > obrien      2005-10-16 08:58:27 UTC
> > > > >
> > > > >   FreeBSD src repository
> > > > >
> > > > >   Modified files:
> > > > >     sys/amd64/amd64      identcpu.c
> > > > >     sys/i386/i386        identcpu.c
> > > > >   Log:
> > > > >   For AMD processors, nullify CPUID.HTT.  FreeBSD has no
> > > > > need for the information it conveys, and it is only
> > > > > confusing people. This fixes incorrect output in the
> > > > > previous commit.
> > > > >
> > > > >   Revision  Changes    Path
> > > > >   1.138     +9 -0      src/sys/amd64/amd64/identcpu.c
> > > > >   1.147     +9 -0      src/sys/i386/i386/identcpu.c
> > > >
> > > > Have you verified you are not breaking `logical_cpus' in
> > > > mp_machdep.c by doing this?
> > > >
> > > > Show me the 'incorrect' output or please back it out.
> > >
> > >     CPU: Dual Core AMD Opteron(tm) Processor 280 (2392.35-MHz
> > > K8-class CPU) ..
> > >     Physical/Logical cores: 2/2
> > >     ..
> > >     FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
> > >      cpu0 (BSP): APIC ID:  0
> > >      cpu1 (AP): APIC ID:  1
> > >      cpu2 (AP): APIC ID:  2
> > >      cpu3 (AP): APIC ID:  3
> > >
> > > I sure as hell have 4 physical cores and no logical cores.
> >
> > The information is per-CPU.  You have two CPUs with dual cores,
> > which means the given information is correct.  Please back it
> > out.
>
> No, this given information is wrong.  AMD does not have
> HyperThreading. You are treating it as if it does.

???  Did I ever mention Hyper-Threading here?  I actually replaced 
misleading 'Hyperthreading' with 'Physical/Logical cores.'

> The rest of the kernel also should not be trying to treat AMD
> dual-core as HyperThreading.

Sigh...  Sure it should not.  That's why there is 
`hyperthreading_cpus' for.

> The only thing that should care in the freebsd kernel right now
> about AMD dual-core is PowerNow! support.  It probably needs to
> know what cores match physical cores so it can proper work in a
> multi-socket system.
>
> Please point to what part of `logical_cpus' in mp_machdep.c you
> feel is broken by this change.
>
> > > I do not think you fully understand what AMD dual-core CPU's.
> >
> > Oh, please...
>
> The code you committed suggest this...

I will just shut up and code if you 'feel' that I am not capable.

Jung-uk Kim