linux如何釋放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
有關/proc/sys/vm/drop_caches的用法在下面進行了說明
/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.
