On Mon, Mar 21, 2016 at 09:23:41AM +0100, Borislav Petkov wrote: > On Mon, Mar 21, 2016 at 11:07:46AM +0800, Huang Rui wrote: > > OK, we will find some fam15h, fam16h platforms to verify it. Please > > wait for my feedback. > > > > But I am confused with c->x86_max_cores /= smp_num_siblings, what is > > the real meaning of c->x86_max_cores here for AMD, the whole compute > > unit numbers per socket? > > Yes, it is the cores and each core can contain two or more logical > threads. In AMD speak, that's the compute unit count. We read it in > detect_ht() from CPUID(1).EBX[23:16] which is LogicalProcessorCount, > i.e., CPUID(8000_0008).ECX[NC] + 1, i.e., the number of cores. And > "cores" in BKDG speak is the number of all cores in a processor which > are distributed across compute units.... > > That's why we divide by the number of siblings, i.e., the number of > cores in a CU, in AMD speak. > > I know, it is confusing but once we're fine with the nomenclature, it'll > become as clear as day. :-) >
OK, actually, there was a topology bug on Carrzio before, the thread number was detected as 1: Before: autotest@autotest-Gardenia88:~$ lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 NUMA node(s): 1 Vendor ID: AuthenticAMD CPU family: 21 Model: 96 Model name: AMD Eng Sample: ZM1810C1Y4381_34/18/12/06_9874 Stepping: 0 CPU MHz: 1400.000 CPU max MHz: 1800.0000 CPU min MHz: 1400.0000 BogoMIPS: 3592.19 Virtualization: AMD-V L1d cache: 32K L1i cache: 64K L2 cache: 1024K NUMA node0 CPU(s): 0-3 Now: ray@hr-ub:~/tip$ lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 2 Core(s) per socket: 2 Socket(s): 1 NUMA node(s): 1 Vendor ID: AuthenticAMD CPU family: 21 Model: 96 Stepping: 0 CPU MHz: 1400.000 BogoMIPS: 3592.19 Virtualization: AMD-V L1d cache: 32K L1i cache: 96K L2 cache: 1024K NUMA node0 CPU(s): 0-3 Looks better. I will test it on fam16h machine tomorrow, if it's OK, will add my Test-by. Thanks, Rui
