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

*** 198,208 ****
          segdev_fault,
          segdev_faulta,
          segdev_setprot,
          segdev_checkprot,
          (int (*)())segdev_badop,        /* kluster */
-         (size_t (*)(struct seg *))NULL, /* swapout */
          segdev_sync,                    /* sync */
          segdev_incore,
          segdev_lockop,                  /* lockop */
          segdev_getprot,
          segdev_getoffset,
--- 198,207 ----