#!/bin/bash
used=`free -m | awk 'NR==2' | awk '{print $3}'`
free=`free -m | awk 'NR==2' | awk '{print $4}'` echo "===========================" >> yl_dropcaches.log
date >> yl_dropcaches.log
echo "Memory usage | [Use：${used}MB][Free：${free}MB]" >> yl_dropcaches.log # drop caches when the free memory less than 10G
if [ $free -le 10000 ] ; then
#sync && echo 1 > /proc/sys/vm/drop_caches
#sync && echo 2 > /proc/sys/vm/drop_caches
sync && echo 3 > /proc/sys/vm/drop_caches
echo "OK" >> yl_dropcaches.log
else
echo "Not required" >> yl_dropcaches.log
fi
https://www.cnblogs.com/zxc2man/p/8175952.html
https://blog.csdn.net/e_wsq/article/details/79905221
https://blog.csdn.net/jfb53440/article/details/79171941