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

*** 872,884 ****
                  } while (all && cur != NULL);
  
                  if (sep->se_failed != 0) {
                          char *reason;
                          switch (sep->se_failed) {
-                         case FSI_FAIL_NOTINMEMORY:
-                                 reason = "thread not in memory";
-                                 break;
                          case FSI_FAIL_THREADCORRUPT:
                                  reason = "thread structure stack info corrupt";
                                  break;
                          case FSI_FAIL_STACKNOTFOUND:
                                  reason = "no consistent stack found";
--- 872,881 ----