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

*** 28,39 ****
  
  
  #ifndef _SYS_DISP_H
  #define _SYS_DISP_H
  
- #pragma ident   "%Z%%M% %I%     %E% SMI"        /* SVr4.0 1.11  */
- 
  #include <sys/priocntl.h>
  #include <sys/thread.h>
  #include <sys/class.h>
  
  #ifdef  __cplusplus
--- 28,37 ----
*** 141,152 ****
  extern void             setfrontdq(kthread_t *);
  extern void             swtch(void);
  extern void             swtch_to(kthread_t *);
  extern void             swtch_from_zombie(void)
                                  __NORETURN;
- extern void             dq_sruninc(kthread_t *);
- extern void             dq_srundec(kthread_t *);
  extern void             cpu_rechoose(kthread_t *);
  extern void             cpu_surrender(kthread_t *);
  extern void             kpreempt(int);
  extern struct cpu       *disp_lowpri_cpu(struct cpu *, struct lgrp_ld *, pri_t,
                              struct cpu *);
--- 139,148 ----