什么等同于 Mac 在 Linux 中的清除？

Question

在 Mac 中，我purge用来释放一些内存。在 Linux（Ubuntu 服务器）中相当于什么？apt-get install purge什么也没给我。如果您不熟悉 Mac，请purge访问它的man页面：

purge(8)                  BSD System Manager's Manual                 purge(8)

NAME
     purge -- force disk cache to be purged (flushed and emptied)

SYNOPSIS
     purge

DESCRIPTION
     Purge can be used to approximate initial boot conditions with a cold disk
     buffer cache for performance analysis. It does not affect anonymous mem-
     ory that has been allocated through malloc, vm_allocate, etc.

SEE ALSO
     sync(8), malloc(3)

                              September 20, 2005

Answer 1

这可以做同样的事情purge：

sync && echo 3 > /proc/sys/vm/drop_caches

来自man proc：

/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 nondestructive operation and dirty objects are
              not freeable, the user should run sync(8) first.

来自man sync：

NAME
       sync - flush file system buffers

DESCRIPTION
       Force changed blocks to disk, update the super block.