Re: broken VM in 2.4.10-pre9

[Ricardo Galli]

On Sun, 16 Sep 2001, Rik van Riel wrote:
>
> > Is there a way to tell the VM to prune its cache? Or a way to limit
> > the amount of cache it uses?
>
> Not yet, I'll make a quick hack for this when I get back next
> week. It's pretty obvious now that the 2.4 kernel cannot get
> enough information to select the right pages to evict from
> memory.

....

On Sun, 16 Sep 2001, Jeremy Zawodny wrote:
>
> Agreed. I'd be great if there was an option to say "Don't swap out
> memory that was allocated by these programs. If you run out of disk
> buffers, toss the oldest ones and start re-using them."

More easy though (for cases of listening mp3's and backups): cache pages
that were accesed only "once"(*) several seconds ago must be discarded
first. It only implies a check against an access counter and a "last
accesed"  epoch fields of the page.

(*) Or by the same process/process group in a very short period, i.e. the
last-access timestamp should be updated only if the previous access was
few seconds ago.

--ricardo