SHM_LOCK under Linux ... do we use this?

Under FreeBSD, we have an option (kern.ipc.shm_use_phys=1) that doesn't
allow shared memory to be swap'd ... under Linux, there is apparently an
application level option that can be used for this purpose:

A privileged user can prevent or allow swapping of a shared memory
segment with the following cmds:

SHM_LOCK prevents swapping of a shared memory segment. The user
must fault in any pages that are required to be present
after ...

I've done a grep through the code, to see if its something that we do use, and
it doesn't seem to come back with anything ... I believe its considered
common knowledge that 'swapping' for a database is evil, so am wondering
if there is some way that we can make use of this to help reduce/eliminate
that from happening?

The "A privileged user can..." part makes me think no, but figured I'd ask
...

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Marc G. Fournier Hub.Org Networking Services (http://www.hub.org)
Email: scrappy(at)hub(dot)org Yahoo!: yscrappy ICQ: 7615664