Linux关闭超线程
Intel的超线程技术能让一个物理核上并行执行两个线程,大多数情况下能提高硬件资源的利用率,增强系统性能。对于cpu密集型的数值程序,超线程技术可能会导致整体程序性能下降. 鉴于此,执行OpenMP或者MPI数值程序时建议关闭超线程技术.
以下是github上找到的动态打开、关闭超线程技术的脚本. 其原理是根据/sys/devices/system/cpu/cpuX/topology/thread_siblings_list
文件找到逻辑核的关系,然后编辑/sys/devices/system/cpu/cpuX/online
文件实现动态开启和关闭超线程技术.
#!/bin/bash HYPERTHREADING=1 function toggleHyperThreading() { for CPU in /sys/devices/system/cpu/cpu[0-9]*; do CPUID=`basename $CPU | cut -b4-` echo -en "CPU: $CPUID\t" [ -e $CPU/online ] && echo "1" > $CPU/online THREAD1=`cat $CPU/topology/thread_siblings_list | cut -f1 -d,` if [ $CPUID = $THREAD1 ]; then echo "-> enable" [ -e $CPU/online ] && echo "1" > $CPU/online else if [ "$HYPERTHREADING" -eq "0" ]; then echo "-> disabled"; else echo "-> enabled"; fi echo "$HYPERTHREADING" > $CPU/online fi done } function enabled() { echo -en "Enabling HyperThreading\n" HYPERTHREADING=1 toggleHyperThreading } function disabled() { echo -en "Disabling HyperThreading\n" HYPERTHREADING=0 toggleHyperThreading } # ONLINE=$(cat /sys/devices/system/cpu/online) OFFLINE=$(cat /sys/devices/system/cpu/offline) echo "---------------------------------------------------" echo -en "CPU's online: $ONLINE\t CPU's offline: $OFFLINE\n" echo "---------------------------------------------------" while true; do read -p "Type in e to enable or d disable hyperThreading or q to quit [e/d/q] ?" ed case $ed in [Ee]* ) enabled; break;; [Dd]* ) disabled;exit;; [Qq]* ) exit;; * ) echo "Please answer e for enable or d for disable hyperThreading.";; esac done
- 脚本需要root执行
- 完成后用lscpu查看Thread(s) per core是否为1
参考:
转载请注明原文出处:https://tlanyan.me/linux-enab...
source script: https://gist.github.com/samueljon/e7818edeb218f5e2f1e3e258949d04c8
2020/05/30更新
以上似乎对集群scheduler PBS不起作用,建议还是在BIOS中关闭!