共计 1562 个字符,预计需要花费 4 分钟才能阅读完成。
转载请注明文章出处:https://tlanyan.me/linux-enab…
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
备注:
- 脚本需
root
权限执行; - 可以通过
cat /proc/cpuinfo
查看启用的 cpu 信息,该命令无需root
权限; -
lscpu
命令可查看 cpu 的状态(无需root
权限):超线程状态下threads per core
数值为 2,禁用时为 1.
参考
- Disable / Enable HyperThreading cores on runtime – linux
正文完
发表至: linux
2019-07-07