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

@@ -437,12 +437,10 @@
 extern int      anon_copy_ptr(struct anon_hdr *, ulong_t,
                     struct anon_hdr *, ulong_t, pgcnt_t, int);
 extern pgcnt_t  anon_grow(struct anon_hdr *, ulong_t *, pgcnt_t, pgcnt_t, int);
 extern void     anon_array_enter(struct anon_map *, ulong_t,
                         anon_sync_obj_t *);
-extern int      anon_array_try_enter(struct anon_map *, ulong_t,
-                        anon_sync_obj_t *);
 extern void     anon_array_exit(anon_sync_obj_t *);
 
 /*
  * anon_resv checks to see if there is enough swap space to fulfill a
  * request and if so, reserves the appropriate anonymous memory resources.