有时候,像mongo这种,对内存只吃不吐的,我们要手动释放一下。

drop_caches的详细文档如下:
Writing to this will cause the kernel to drop clean caches, dentries and inodes from memory, causing that memory to become free.
To free pagecache:(释放网页内存)
* echo 1 > /proc/sys/vm/drop_caches
To free dentries and inodes:(释放dentries和inode缓存)
* echo 2 > /proc/sys/vm/drop_caches
To free pagecache, dentries and inodes:(释放页面缓存,dentries和inode)
* echo 3 > /proc/sys/vm/drop_caches
As this is a non-destructive operation, and dirty objects are notfreeable, the user should run "sync" first in order to make sure allcached objects are freed.