1、SMT,Simultaneous Multithreading
同步多线程(SMT)是一种在一个CPU 的时钟周期内能够执行来自多个线程的指令的硬件多线程技术。本质上，同步多线程是一种将线程级并行处理(多CPU)转化为指令级并行处理(同一CPU)的方法。
2、命令ppc64_cpu
NAME
ppc64_cpu - cpu settings utility
SYNOPSIS
ppc64_cpu [OPTION]
DESCRIPTION
This utility allows users to view and set the cpu SMT, DSCR and smt-snooze-delay settings.
OPTIONS
--smt Get current SMT state.
--smt={on|off}
Set SMT state.
--cores-present
Get the number of cores present.
--cores-on
Get the number of cores currently online.
--cores-on=X
Put exactly X cores online.
--dscr [-p <pid>]
Get current DSCR system setting or, optionally, for <pid>.
--dscr=<val> [-p <pid>]
Change DSCR system setting or, optionally, for <pid>.
--smt-snooze-delay
Get current smt-snooze-delay setting.
--smt-snooze-delay=<val>
Change smt-snooze-delay setting.
--run-mode
Get current diagnostics run mode.
--run-mode=<val>
Set current diagnostics run mode.
--frequency [-t <time>]
Determine cpu frequency for <time> seconds, default is 1 second.
--subcores-per-core
Get number of subcores per core.
--subcores-per-core=X
Set subcores per core to X (1 or 4).
--threads-per-core
Get number of threads per core.
--info Display system state information.
3、开启及状态
3.1.查看SMT状态
root@zhaippc64le:~# ppc64_cpu --smt
SMT is off
此时用ppc64_cpu --info查看时，只有第一列带*号
root@zhaippc64le:~# ppc64_cpu --info
Core 0: 0* 1 2 3 4 5 6 7
Core 1: 8* 9 10 11 12 13 14 15
Core 2: 16* 17 18 19 20 21 22 23
Core 3: 24* 25 26 27 28 29 30 31
Core 4: 32* 33 34 35 36 37 38 39
Core 5: 40 41 42 43 44 45 46 47
Core 6: 48* 49 50 51 52 53 54 55
Core 7: 56* 57 58 59 60 61 62 63
Core 8: 64* 65 66 67 68 69 70 71
Core 9: 72* 73 74 75 76 77 78 79
3.2.开启
ppc64_cpu --smt=on
# ppc64_cpu --smt
SMT is on
用ppc64_cpu --info查看时，只有所有列带*号
# ppc64_cpu --info
Core 0: 0* 1* 2* 3* 4* 5* 6* 7*
Core 1: 8* 9* 10* 11* 12* 13* 14* 15*
Core 2: 16* 17* 18* 19* 20* 21* 22* 23*
Core 3: 24* 25* 26* 27* 28* 29* 30* 31*
Core 4: 32* 33* 34* 35* 36* 37* 38* 39*
Core 5: 40* 41* 42* 43* 44* 45* 46* 47*
Core 6: 48* 49* 50* 51* 52* 53* 54* 55*
Core 7: 56* 57* 58* 59* 60* 61* 62* 63*
Core 8: 64* 65* 66* 67* 68* 69* 70* 71*
Core 9: 72* 73* 74* 75* 76* 77* 78* 79*
4、lscpu及/proc/cpuinfo
# lscpu
Architecture: ppc64le
Byte Order:Little Endian
CPU(s):160
On-line CPU(s) list: 0-159
Thread(s) per core:8
Core(s) per socket:5
Socket(s): 2
NUMA node(s): 2
Model: 8284-22A
CPU max MHz: 3690.0000
CPU min MHz: 2061.0000
L1d cache: 64K
L1i cache: 32K
L2 cache: 512K
L3 cache: 8192K
NUMA node0 CPU(s): 0-39
NUMA node1 CPU(s): 40-79
cat /proc/cpuinfo后查看processor，用ppc64_cpu --info查看到的带*号的cpu号都会在/proc/cpuinfo中显示。