Re: [PATCH 2/3] x86/topology: Fix AMD core count

[Huang Rui <ray.huang@amd.com>]

On Mon, Mar 21, 2016 at 09:26:43AM +0100, Borislav Petkov wrote:
> On Mon, Mar 21, 2016 at 11:46:19AM +0800, Huang Rui wrote:
> > I quickly applied this patch on tip/master with on a fam15h machine.
> > The issue is still existed, only one core can be detected.
> 
> Huh, what?
> 
> So that 6386 has 16 cores, according to wikipedia, that must be 8
> compute units. Correct?
> 

Yes, there are two sockets in this platform. 32 cores and 16 compute units.

> Are you saying, you have only one core in /proc/cpuinfo?
> 
> Can you send full dmesg please?
> 

Apology to bring a surprise. Our test machine didn't configure the
CONFIG_SMP just now because it was to reproduce another build issue
before...
So an incorrect "only one" core is detected, sorry. Please ignore previous
result. I will do more testing on other platforms.

Now I re-build system, please see the correct message:

ray@hr-ub:~/tip$ cat /sys/devices/system/cpu/cpu2/topology/thread_siblings_list
2-3
ray@hr-ub:~/tip$ cat /sys/devices/system/cpu/cpu2/topology/core_siblings_list
0-15


processor       : 31
vendor_id       : AuthenticAMD
cpu family      : 21
model           : 2
model name      : AMD Opteron(tm) Processor 6386 SE
stepping        : 0
microcode       : 0x6000822
cpu MHz         : 1400.000
cache size      : 2048 KB
physical id     : 1
siblings        : 16
core id         : 7
cpu cores       : 8
apicid          : 79
initial apicid  : 47
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
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 pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc
extd_apicid amd_dcm aperfmperf eagerfpu pni pclmulqdq monitor ssse3
fma cx16 sse4_1 sse4_2 popcnt aes xsave avx f16c lahf_lm cmp_legacy
svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs
xop skinit wdt lwp fma4 tce nodeid_msr tbm topoext perfctr_core
perfctr_nb cpb hw_pstate vmmcall bmi1 arat npt lbrv svm_lock nrip_save
tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold
bugs            : fxsave_leak sysret_ss_attrs
bogomips        : 5585.90
TLB size        : 1536 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 48 bits physical, 48 bits virtual
power management: ts ttp tm 100mhzsteps hwpstate cpb eff_freq_ro


Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                32
On-line CPU(s) list:   0-31
Thread(s) per core:    2
Core(s) per socket:    8
Socket(s):             2
NUMA node(s):          4
Vendor ID:             AuthenticAMD
CPU family:            21
Model:                 2
Stepping:              0
CPU MHz:               1400.000
BogoMIPS:              5585.90
Virtualization:        AMD-V
L1d cache:             16K
L1i cache:             64K
L2 cache:              2048K
L3 cache:              6144K
NUMA node0 CPU(s):     0-7
NUMA node1 CPU(s):     8-15
NUMA node2 CPU(s):     16-23
NUMA node3 CPU(s):     24-31


Thanks,
Rui