清理mem cache缓存

$sync

 

通过修改proc系统的drop_caches清理free的cache

 

$echo 3 > /proc/sys/vm/drop_caches

 

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:

 

* echo 1 > /proc/sys/vm/drop_caches

 

To free dentries and inodes:

 

* echo 2 > /proc/sys/vm/drop_caches

 

To free pagecache, dentries and inodes:

 

* 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.