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

*** 652,668 ****
                          continue;
  
                  thread_lock(t);
                  switch (t->t_state) {
                  case TS_SLEEP:
-                         /*
-                          * Don't touch the lwp is it is swapped out.
-                          */
-                         if (!(t->t_schedflag & TS_LOAD)) {
-                                 mstate = LMS_SLEEP;
-                                 break;
-                         }
                          switch (mstate = ttolwp(t)->lwp_mstate.ms_prev) {
                          case LMS_TFAULT:
                          case LMS_DFAULT:
                          case LMS_KFAULT:
                          case LMS_USER_LOCK:
--- 652,661 ----