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

*** 117,127 ****
          segkpm_fault,
          SEGKPM_BADOP(int),      /* faulta */
          SEGKPM_BADOP(int),      /* setprot */
          SEGKPM_BADOP(int),      /* checkprot */
          SEGKPM_BADOP(int),      /* kluster */
-         SEGKPM_BADOP(size_t),   /* swapout */
          SEGKPM_BADOP(int),      /* sync */
          SEGKPM_BADOP(size_t),   /* incore */
          SEGKPM_BADOP(int),      /* lockop */
          SEGKPM_BADOP(int),      /* getprot */
          SEGKPM_BADOP(u_offset_t), /* getoffset */
--- 117,126 ----