>I have a question about using mmap independent of ObjectStore (but
 >in the same process).
 >
 >I read the documentation for:
 >   objectstore::set_reserve_as_mode(os_boolean new_mode)
 >
 >Does this have a performance impact on Solaris 2.x?

No.

 >If so, can I reserve address space before the mmap and
 >turn off reserve address space after the mmap?

No.  It's only done at initialization time.

 >What is the usual way of solving this problem?  Or is
 >it a problem?

It's not a problem for you.