Re: Kernel VS application file caching

[David Holland <dholland-tech%netbsd.org@localhost>]

On Thu, Jan 21, 2010 at 02:25:12PM +0000, Sad Clouds wrote:
 > Another question is this: is it possible for userlevel applications
 > to tell kernel not to cache certain files? For example application
 > might want to keep frequently accesses .html .jpeg files in memory
 > and not cache rarely accessed huge files, which would evict many
 > other files when loaded into core.

Not very well. There are things you can do, but the overhead of
telling the kernel what you want tends to outweigh the savings in most
cases.

It can be done effectively (see Chris Small's thesis(*)) but only with
a specially designed platform, not with NetBSD.


(*) http://www.dogfish.org/chris/papers/thesis.pdf

-- 
David A. Holland
dholland%netbsd.org@localhost