physmem and swap servers

[Ludovic Courtès]

Hi,

In section "Sending Data to Swap" of the VMM chapter from the doc, it is
said that the swap server may reside in (or be proxied by) physmem.
This way, an application may be able to recover the contents of a frame
before it is sent to swap.

My question is: How would an application be able to use a custom swap
server?  Would there be a special method to tell physmem that such
application would like to use such swap server?  For example:

  pm_assign_swap_server (task_id_t task, thread_id_t swap_server);

Thanks,
Ludovic.