Re: Athlon 64 X2 cpuinfo oddities

["Rafael J. Wysocki" <rjw@sisk.pl>]

Hi,

On Monday, 9 January 2006 21:18, Jesper Juhl wrote:
> I recently bought a Dual Core AMD Athlon 64 X2 4400+ CPU and dropped a
> 2.6.15 kernel on the box and it runs very nice, but /proc/cpuinfo
> shows a few things that seem slightly odd to me (haven't tried earlier
> kernels on this so I don't know if cpuinfo looked different
> previously).
> It may be that it's absolutely correct and not odd at all, but I
> thought I'd just ask :)
> 
> Here's what  cat /proc/cpuinfo  shows :
> 
> juhl@dragon:~$ cat /proc/cpuinfo
> processor       : 0
> vendor_id       : AuthenticAMD
> cpu family      : 15
> model           : 35
> model name      : AMD Athlon(tm) 64 X2 Dual Core Processor 4400+
> stepping        : 2
> cpu MHz         : 2200.260
> cache size      : 1024 KB
> physical id     : 0
> siblings        : 1
> core id         : 0
> cpu cores       : 1
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 1
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext
> fxsr_opt lm 3dnowext 3dnow pni lahf_lm cmp_legacy
> bogomips        : 4403.36
> 
> processor       : 1
> vendor_id       : AuthenticAMD
> cpu family      : 15
> model           : 35
> model name      : AMD Athlon(tm) 64 X2 Dual Core Processor 4400+
> stepping        : 2
> cpu MHz         : 2200.260
> cache size      : 1024 KB
> physical id     : 127
> siblings        : 1
> core id         : 1
> cpu cores       : 1
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 1
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext
> fxsr_opt lm 3dnowext 3dnow pni lahf_lm cmp_legacy
> bogomips        : 4399.53
> 
> 
> So, what's odd with that?
> 
> Well, first of all you'll notice that the second core shows a
> "physical id" of 127 while the first core shows an id of 0.  Shouldn't
> the second core be id 1, just like the "core id" fields are 0 & 1?

FWIW, I'm running 2.6.15 on Athlon X2 4200 and the second core's
physical id is 0 (ie. same as of the frist one), the number of siblings
for each core is 2, and the "cpu cores" value is 2 as well (yours is 1,
apparently ;-)).

Greetings,
Rafael