>My fix on FreeBSD is only a work around, and I'll have a rather complete
>fix ready from my queue today or tomorrow.  

right.  you can't base a general fix on testing the reference count
being equal to one because it is easy to clip your way up to a 
high reference count.


>The key to the fix (which I have actually had available in my personal
>kernels for quite a while), is to know when an object's pages (as
>opposed to mappings) can be removed.  Your comments about object
>reference counts are true, and the effect cascades, to the point
>where it is apparent that such reference counts are not applicable
>for using them as indicators of the appropriateness of removing
>pages for memory and swap.  

yeah, that is the exact conclusion i reached when i brought this 
issue up to you and david greenman last spring when i was deciding 
how best to handle this problem in uvm.   the issue is made more 
complex by the fact that you need to track the references to parts
of an object that may not currently be resident.

chuck