Prune obsolete raw_node_ref's from RAM

[David Woodhouse]

On Tue, 2004-07-13 at 16:18 +0200, Øyvind Harboe wrote:
> - Is the code correct? 

It looks OK at first glance but I can't actually tell. List mangling
code is hard enough to read when it's in the style I understand :)

I've rewritten it and just posted that version. 

> - What performance impact does it have? 

It'll go walking the lists every time a node is obsoleted. My guess is
it'll make the performance suck _hard_. But it will get you your memory
back. I suspect it should be a configuration option -- or maybe we could
stick the list-walking code into a separate function and call it
periodically to do the cleanup, rather than doing it every time.

Could do with seeing some profiling info.

-- 
dwmw2