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
thatare 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@hub.org           Yahoo!: yscrappy              ICQ: 7615664