Re: Idea for improving linux buffer cache behaviour

[Mike Fedyk <mfedyk@matchmail.com>]

On Sat, Oct 04, 2003 at 03:14:14PM -0400, Rik van Riel wrote:
> On Sat, 4 Oct 2003, David Ashley wrote:
> 
> > Forgive me if this has already been thought of, or is obsolete, or is
> > just plain a bad idea, but here it is:
> 
> Do you also want an answer if the kernel already does
> exactly what you are suggesting ? ;)
> 

Then why doesn't it work better?

> > 1) Lowest access count looked at first to toss
> > 2) If access counts equal, throw out oldest first
> 
> > The net result is commonly used items you very much want to remain in
> > cache always quickly get rated very highly as the system is used.
> 
> Which results in exactly the behaviour you're complaining
> about ;))

So, you use the system, have glibc loaded, and then play a dvd, and now
glibc needs to be re-read because it's not in cache.

Why wasn't glibc (one example) kept in cache with the streaming read from
the dvd?