在安装Ubuntu的POWER服务器上，开启SMT

深藏阁楼爱情的钟 2022-07-25 15:36 156阅读 0赞

# 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 ##

## `<span style="font-size:14px;">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.</span>` ##

## 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。**

参考：

1 [处理器CPU概念及CPU多线程][CPU_CPU]：http://blog.csdn.net/zhaihaifei/article/details/51015528

[CPU_CPU]: http://blog.csdn.net/zhaihaifei/article/details/51015528