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

@@ -652,17 +652,10 @@
                         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: