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

@@ -275,11 +275,11 @@
          * initialize t0
          */
         t0.t_stk = (caddr_t)rp - MINFRAME;
         t0.t_stkbase = t0stack;
         t0.t_pri = maxclsyspri - 3;
-        t0.t_schedflag = TS_LOAD | TS_DONT_SWAP;
+        t0.t_schedflag = 0;
         t0.t_procp = &p0;
         t0.t_plockp = &p0lock.pl_lock;
         t0.t_lwp = &lwp0;
         t0.t_forw = &t0;
         t0.t_back = &t0;