---------- Forwarded message ----------
From:
Stuart Henderson <stu@spacehopper.org>
Date: Tue, Jan 15, 2013 at 6:41 AM
Subject: Re: adding support to mdb
To: Friedrich Locke <
friedrich.locke@gmail.com>
On 2013/01/14 21:31, Friedrich Locke wrote:
> Hi!
>
> people from openldap group have already migrated to mdb.
> Why OpenBSD has such problems. On other OSes, things work nicely.
> BTW, no offense, i do like obsd, but things like make me upset.
I suspect that the MDB code probably requires something from the
OS that OpenBSD doesn't have (coherent buffer and page caches -
http://utcc.utoronto.ca/~cks/space/blog/unix/UnifiedCacheMmap)
If I'm correct then it will appear to work, but with a risk of
database corruption. For this reason I won't enable this in the
OpenLDAP port unless someone who knows the area well is
satisfied that it's safe.
Some other database code which likes to use mmap (e.g. cyrus
skiplist) takes into account the various types of cache behaviour
and has options to avoid using mmap. It doesn't appear that MDB
has this yet.