remove whole-process swapping
Long before Unix supported paging, it used process swapping to reclaim
memory.  The code is there and in theory it runs when we get *extremely* low
on memory.  In practice, it never runs since the definition of low-on-memory
is antiquated. (XXX: define what antiquated means)
You can check the number of swapout/swapin events with kstats:
$ kstat -p ::vm:swapin ::vm:swapout

@@ -1213,12 +1213,10 @@
         nrp->req = req;
         nrp->cr = cr;
         nrp->ro = ro;
         nrp->thread = curthread;
 
-        ASSERT(curthread->t_schedflag & TS_DONT_SWAP);
-
         /*
          * Look to see if there is already a cluster started
          * for this file.
          */
         mutex_enter(&rfs_async_write_lock);