hi,

> > however, i concluded that it didn't work.
> > a split can occur even if you didn't merge entries
> > (eg. when you map [0..100] and then unmap [10..90].
> > of course, one doing such a thing can't assume unmap won't block.)
> > and it can consume "reserved" entries for merged maps which are
> > expected to be unmapped without blocking.
> 
> Hm.  Yah, good point.  What about just keeping a list of extras around 
> anyway (maybe allocating 16 or so, and when you reach, say, 8, try to 
> allocate another 8 or whatever).

how do you know 16 or so is enough?

YAMAMOTO Takashi