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

*** 357,368 ****
          struct regs *rp = lwptoregs(lwp);
          int     repost;
  
          t->t_pre_sys = repost = 0;      /* clear pre-syscall processing flag */
  
-         ASSERT(t->t_schedflag & TS_DONT_SWAP);
- 
          syscall_mstate(LMS_USER, LMS_SYSTEM);
  
          /*
           * The syscall arguments in the out registers should be pointed to
           * by lwp_ap.  If the args need to be copied so that the outs can
--- 357,366 ----