On Tue, Apr 03, 2001 at 08:23:01PM +0200, Lars Heidieker wrote:
	> For me it would look right to make vnode pages that are not mapped by any
	> process inactive.
	> This would allow the fs cache to grow to approx 1/3 of main mem and it
	> would be able to use even more memory if it is free.

	this is basically what eduardo proposed, and the problem with that is that
	the other 2/3 of memory will more-or-less always contain anon data for
	user processes (such as our favorite application, netscape).  so we
	wouldn't be able to use any of that memory for caching file data
	*no matter how long the process is idle*.  the process could sleep
	for *years* and we would never page it out.

It doesn't exactly limit the buffer cache to 1/3 of memory.  It just
prevents the buffer cache from stealin more than 1/3 of memory.  The
buffer cache can grab any pages that migrate onto the free list in
other ways, such as process exit.  If the RAM really is unused, then
my patch will still allow it to be taken by the buffer cache.

Eduardo