Re: An idea for prefetching swapped memory...

[mru@users.sourceforge.net (Måns Rullgård)]

Christophe Saout <christophe@saout.de> writes:

> > > With this feature there should be no performance decrease
> > > because only free resources would be used, and if pages were
> > > swapped in but not be used, they stay not dirty and so have not
> > > to be written to disk when they are swapped out again. But the
> > > improvements should be obvious if simply the last swaped out
> > > pages are swapped in again...
> > 
> > This has been argued before. Why would the last swapped out pages
> > be the best to swap in? The vm subsystem has (somehow) decided
> > they're the least likely to be used again so why swap them in?
> 
> Are you sure this is working? When I'm watching a video ofer NFS on
> my machine which is idle (just X and mplayer, gnome in background,
> 256 MB of memory, 512 swap), after 30 minutes or so, the playback
> starts to jump. The cpu usage is below 10%, and it even does this
> when both X and mplayer are renice to -19 (!). So the VM swapped
> everything out and after 30 minutes it starts to swap out X oder
> mplayer itself, which is immediately swapped back in but the video
> jumps... :-(

How much of your memory is in use?  Are you sure there isn't a memory
leak somewhere in mplayer?

-- 
Måns Rullgård
mru@users.sf.net