Re: [PATCH] O_STREAMING - flag for optimal streaming I/O

[Xavier Bestel]

Le jeu 10/10/2002 à 13:01, Helge Hafting a écrit :
> Giuliano Pochini wrote:
> 
> > Yes, it makes sense, but it's useless or harmful to discard caches
> > if nobody else needs memory. You just lose data that may be
> > requested in the future for no reason.
> 
> Sure, so the ideal is to not drop unconditionally, but
> make sure that the "finished" O_STREAMING pages are
> the very first ones to go whenever memory pressure happens.

IMHO this shoudln't be taken care of. As you say it, a linux box has no
free memory (or it's been very recently booted), so the problem is not
to make O_STREAMING pages "low priority", but just to make them not stay
in the cache (perhaps just keep a few KB worth of them in case of a
limited seek back, but not more).

	Xav