cvs commit: src/usr.bin/top machine.c

[Bruce Evans]

bde         2007-06-15 12:03:07 UTC

  FreeBSD src repository

  Modified files:
    usr.bin/top          machine.c 
  Log:
  Third stage of unbreaking printing of pseudo-nice values (realtime
  priorities, etc.) in the NICE field:
  
  Use a combination of pri_native and pri_user instead of pri_level to
  guess the original realtime priority.  Using pri_level here has been
  wrong since 2001/02/12.  Using only pri_native here would be correct
  if the kernel actually initialized it reasonably.  (The kernel exports
  its raw td_base_priority as pri_native, but userland mostly wants a
  refined base priority).  Give up on waiting pri_native to work correctly
  and only use it when there is nothing better (for kthreads).
  
  This should reduce printing of bizarre pseudo-nice values.  Bizarre
  values are still printed if we observe a transient borrowed priority
  for a kthread (transient borrowing is the main thing that makes the
  raw td_base_priority almost useless in userland), or if there is a
  kernel bug.  One current kernel bug involves the kernel idprio thread
  pagezero permanently changing its priority from PRI_MAX_IDLE (255) to
  PUSER (160).  Then the bizarre value "ki-6" is printed instead of
  "ki31".  Here "-6" is PRI_MIN_IDLE - PUSER = -64 truncated to 2
  characters.  We are observing a transient borrowed priority that has
  become permanent due to a bug.
  
  ps/print.c:priorityr() needs similar changes (including ones in stage 2
  here).
  
  Revision  Changes    Path
  1.81      +25 -2     src/usr.bin/top/machine.c