/proc/sys/vm/drop_caches (since Linux 2.6.16) function & usage.
Writing to this file causes the kernel to drop clean caches,dentries and inodes from memory, causing that memory to become free.
To free pagecache, use
echo 1 > /proc/sys/vm/drop_caches;
to free dentries and inodes, use
echo 2 > /proc/sys/vm/drop_caches;
to free pagecache, dentries and inodes, use
echo 3 >/proc/sys/vm/drop_caches.
Because this is a non-destructive operation and dirty objects are not freeable, the user should run sync first.
本文转自 朱科强 51CTO博客，原文链接：http://blog.51cto.com/zhukeqiang/1731266，如需转载请自行联系原作者
