On Thu, Jun 20, 2002 at 04:23:26PM +0200, Wojciech Puchar wrote:
> > > others can have 10 partitions, one can mostly do I/O on one partition,
> > > another spread it evenly. what i don't understand?
> >
> > Because you may want to say, e.g. that the swap, / and /usr partition are
> > highter priorities.
> > The usual way to solve this is to add more disks, but it's not always possible.
> 
> 
> sounds different as an option. thanks for explanation

I've been reading this thread - and keeping quiet for a change...

I wonder if people are looking in the wrong place!

Maybe the number of queued disk write requests generated by the
pagedaemon? (ie writes that are being done to generate free pages)
should be restricted?
That way it would never take too long for a read request (to page
something in) to be executed.
After all pages don't get freed faster if you have more writes
scheduled.

The other question is which pages are chosed to be invalidated?
If someone is copying a large file, or making a large iso image,
then you actually want to discard the pages that have been used
earlier by the copy - rather than those used by the long standing
X server etc.

ISTM that pages that have been used a lot of times but not in
the immediate past should be preserved in preference to pages
that have only been used once but very recently.
(a naive implemtation of this wort work though...)


	David

-- 
David Laight: david@l8s.co.uk