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Re: Performance Tracker project update

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To: Erik Cederstrand <erik@...>
Cc: freebsd-performance@freebsd.org <freebsd-performance@...>
Date: Wednesday, January 23, 2008 - 3:11 pm

Erik Cederstrand wrote:

Sounds good.


Interesting.  Some candidate changes from 2007-10-02:

   Modified files:
     contrib/gcc          opts.c
   Log:
   Do not imply -ftree-vrp with -O2 and above.  One must implicitly specify
   '-ftree-vrp' if one wants it.
   Some bad code generation has been tracked to -ftree-vrp.  jdk1{5,6} are
   notable examples.

     sys/kern             sched_ule.c
   Log:
    - Move the rebalancer back into hardclock to prevent potential softclock
      starvation caused by unbalanced interrupt loads.
    - Change the rebalancer to work on stathz ticks but retain 
randomization.
    - Simplify locking in tdq_idled() to use the tdq_lock_pair() rather than
      complex sequences of locks to avoid deadlock.


     sys/kern             sched_ule.c
   Log:
    - Reassign the thread queue lock to newtd prior to switching.  Assigning
      after the switch leads to a race where the outgoing thread still owns
      the local queue lock while another cpu may switch it in.  This race
      is only possible on machines where cpu_switch can take significantly
      longer on different cpus which in practice means HTT machines with
      unfair thread scheduling algorithms.

Is anyone else able to look into this?


:)

Kris
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Messages in current thread:
Re: Performance Tracker project update, Kris Kennaway, (Wed Jan 23, 7:44 am)
Re: Performance Tracker project update, Borja Marcos, (Thu Jan 24, 4:53 am)
Re: Performance Tracker project update, Ivan Voras, (Wed Jan 23, 8:16 pm)
Re: Performance Tracker project update, Erik Cederstrand, (Thu Jan 24, 6:28 am)
Re: Performance Tracker project update, Ivan Voras, (Thu Jan 24, 7:05 am)
Re: Performance Tracker project update, Kris Kennaway, (Thu Jan 24, 7:06 am)
Re: Performance Tracker project update, Ivan Voras, (Thu Jan 24, 7:15 am)
Re: Performance Tracker project update, Kris Kennaway, (Thu Jan 24, 7:26 am)
Re: Performance Tracker project update, Erik Cederstrand, (Wed Jan 23, 9:49 am)
Re: Performance Tracker project update, Robert Watson, (Wed Jan 23, 3:40 pm)
Re: Performance Tracker project update, Erik Cederstrand, (Wed Jan 23, 4:59 pm)
Re: Performance Tracker project update, Alexander Leidinger, (Thu Jan 24, 3:58 am)
Re: Performance Tracker project update, Erik Cederstrand, (Thu Jan 24, 6:02 am)
Re: Performance Tracker project update, Kris Kennaway, (Thu Jan 24, 7:08 am)
Re: Performance Tracker project update, Alexander Leidinger, (Thu Jan 24, 7:43 am)
Re: Performance Tracker project update, Erik Cederstrand, (Thu Jan 24, 8:14 am)
Re: Performance Tracker project update, Kris Kennaway, (Wed Jan 23, 3:11 pm)
Re: Performance Tracker project update, Kris Kennaway, (Wed Jan 23, 9:58 pm)
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