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

@@ -489,11 +489,10 @@
 
         ASSERT_STACK_ALIGNED();
 
         type = rp->r_trapno;
         CPU_STATS_ADDQ(CPU, sys, trap, 1);
-        ASSERT(ct->t_schedflag & TS_DONT_SWAP);
 
         if (type == T_PGFLT) {
 
                 errcode = rp->r_err;
                 if (errcode & PF_ERR_WRITE)