File cache size on Linux

[Shestakov]

Does somebody knows can we set a limitation of a file cache size in following Linux clones:
-- RH advanced server 2.1
-- Suse 8.0 (8.1)
-- RH 7.3, 8.x

Is it possible or not?
If it possible - Does it depend from a filesystem types (ext2/ext3...) or not?
What kernel parameter(s) I have to use for it?

I understand, that question isn't is directly "oracle question".
but in any way this is "oracle environment question".

Thanks.

[Shestakov]

I found this parameter(s):

/proc/sys/vm/buffermem