linux下关闭cpu核心

查看在线CPU核心

cat /sys/devices/system/cpu/online

输入top，启动后按数字1列出所有CPU核

强制CPU5下线（考虑到服务存在多路，应该理解为Core5）

echo 0 > /sys/devices/system/cpu/cpu5/online

#!/bin/bash  

# 检查是否有参数传入  
if [ "$#" -eq 0 ]; then  
    # 如果没有参数，显示在线的核心数  
    ranges=$(cat /sys/devices/system/cpu/online)  
    # 假设范围是连续的，如"0-3"，则计算结束数字+1  
    last_cpu=$(echo "$ranges" | sed 's/^.*-\([0-9]*\)$/\1/')  
    echo "Online CPUs: $((last_cpu + 1))" 
else  
    case "$1" in  
        1)  
            # 离线 CPU3  
            echo 0 > /sys/devices/system/cpu/cpu3/online  
            ;;  
        2)  
            # 离线 CPU3 和 CPU2  
            echo 0 > /sys/devices/system/cpu/cpu3/online  
            echo 0 > /sys/devices/system/cpu/cpu2/online  
            ;;  
        3)  
            # 离线 CPU3, CPU2, 和 CPU1  
            echo 0 > /sys/devices/system/cpu/cpu3/online  
            echo 0 > /sys/devices/system/cpu/cpu2/online  
            echo 0 > /sys/devices/system/cpu/cpu1/online  
            ;;  
        r)  
            # 在线 CPU1, CPU2, 和 CPU3  
            echo 1 > /sys/devices/system/cpu/cpu1/online  
            echo 1 > /sys/devices/system/cpu/cpu2/online  
            echo 1 > /sys/devices/system/cpu/cpu3/online  
            ;;  
        *)  
            # 如果参数不是1, 2, 3, 或 r，则打印帮助信息  
            echo "Usage: $0 [1|2|3|r]"  
            echo "    1: Offline CPU3"  
            echo "    2: Offline CPU3 and CPU2"  
            echo "    3: Offline CPU3, CPU2, and CPU1"  
            echo "    r: Online CPU1, CPU2, and CPU3"  
            ;;  
    esac  
fi