linux如何释放cache

欢迎进入Linux社区论坛，与200万技术人员互动交流 >>进入

　　linux如何释放cache

　　[root@master ~]# free -m

　　total used free shared buffers cached

　　Mem: 2009 1999 9 0 1308 437

　　-/+ buffers/cache: 253 1756

　　Swap: 5951 0 5951

　　[root@master ~]# cat /proc/sys/vm/drop_caches

　　0

　　[root@master ~]# echo 3 > /proc/sys/vm/drop_caches

　　[root@master ~]# cat /proc/sys/vm/drop_caches

　　3

　　[root@master ~]# sync

　　[root@master ~]# free -m

　　total used free shared buffers cached

　　Mem: 2009 463 1545 0 176 49

　　-/+ buffers/cache: 236 1772

　　Swap: 5951 0 5951

　　有关/proc/sys/vm/drop_caches的用法在下面进行了说明

　　/proc/sys/vm/drop_caches （since Linux 2.6.16）

　　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（8） first.