On Tue, Sep 13, 2005 at 08:14:32AM -0700, Bill Studenmund wrote:
> > That's not my question. Let me try to rephrase it:
> > Will "tmpfs" kick against UVM hard enough to get memory e.g. by flushing
> > pages from the buffer cache?
> Probably not. We don't have a way for file systems to do this in general.

That's bad.

> I think we need one. :-)

Yes, probably. There's of course a problem with that:
When "tmpfs" kicks UVM to free a page, UVM might kick UBC to flush a dirty
page beloging to a vnode of the very same "tmpfs" instance.

Thinking about that further it could already happen right now:
1.) The system needs a free page but there are none.
2.) UBC tries to write a dirty page to a "tmpfs" instance.
3.) "tmpfs" tries to allocate a page to store the date from the dirty page.

How does "tmpfs" deal with that?

	Kind regards

-- 
Matthias Scheler                                  http://scheler.de/~matthias/