mmap() on HP-UX 11

[Mika Iisakkila]

Does anyone know what the current status on using mmap() on HP-UX is?
Cyrus documentation only mentions HP-UX 9 and 10 as not working (probably
because that chapter is just old) but I think 11.11 is supposed to be
greatly improved in this area.

Cyrus 2.0.16 has been running just fine with no_mmap, though; the
reason I'm asking is that I tried getting rid of BDB (a general
nuisance) during an 2.1 upgrade, but skiplist is unusably slow
without mmap(). With some 50000 mailboxes, initial startup took over
an hour, and deleting a user kept that particular imapd spinning for
over 30 minutes of CPU time! I'm not quite sure where the problem was
since deleting sub-mailboxes (user.account.mailbox) worked quite
snappy; however, after I reverted to DB 4.1 as the mailbox database
backend, all was back to normal.

If no-one has tried this on 11.11, I probably will, but what
are the problems I should look for, and what kind of usage would
trigger them?

--mika