Buffer cache

[Susumu Takuwa <susumu-t@po.sakura.ne.jp>]

I have question about Buffer cache and command `free'.

On my debian 2.2 with linux kernel 2.2.17, i get the
memory information using command `free'.

$ free
             total       used       free     shared    buffers     cached
Mem:         46076      45024       1052       6836       4944      18740
-/+ buffers/cache:      21340      24736
Swap:        98748       3952      94796

Well, i understand Buffer cache existing between Block 
device and Filesystem(ex:ext2 filesystem).

	-----------------
	|  Filesystem   |
	----------------- 
	|  Buffer cache |
	-----------------
	|  Block device |
	-----------------

And, i understand following:

[1]The sum of `buffers' and `cache' under command `free'
   is the amount of Buffer cache area. 
[2]In Buffer cache area, `buffers' is no data cached
   space and `cache' is the data cached space.

My understanding is correct?

regards,


	Susumu Takuwa