cvs commit: src/sys/kern subr_sleepqueue.c

[Jeff Roberson]

jeff        2008-03-19 07:22:07 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             subr_sleepqueue.c 
  Log:
   - Add a facility similar to LOCK_PROFILING under SLEEPQUEUE_PROFILING.  Keep
     a simple (wmesg, count) tuple in a hash to keep track of how many times
     we sleep at each wait message.  We hash on message and not channel.  No
     line number information is given as typically wait messages are not used in
     more than one place.  Identical strings defined at different addresses will
     show up with seperate counters.
   - Use debug.sleepq.enable to enable, .reset to reset, and .stats dumps stats.
   - Do an unsynchronized check in sleepq_switch() prior to switching before
     calling sleepq_profile() which uses a global lock to synchronize the hash.
     Only sleeps which actually cause a context switch are counted.
  
  Revision  Changes    Path
  1.49      +159 -1    src/sys/kern/subr_sleepqueue.c