Date: Thu, 4 Jan 2007 12:16:19 +0000 (UTC) From: Jeff Roberson <jeff@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/kern sched_ule.c Message-ID: <200701041216.l04CGKaZ063658@repoman.freebsd.org>
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jeff        2007-01-04 12:16:19 UTC
  FreeBSD src repository
  Modified files:
    sys/kern             sched_ule.c 
  Log:
   - Only allow the tdq_idx to increase by one each tick rather than up to
     the most recently chosen index.  This significantly improves nice
     behavior.  This allows a lower priority thread to run some multiple of
     times before the higher priority thread makes it to the front of
     the queue.  A nice +20 cpu hog now only gets ~5% of the cpu when running
     with a nice 0 cpu hog and about 1.5% with a nice -20 hog.  A nice
     difference of 1 makes a 4% difference in cpu usage between two hogs.
   - Track a seperate insert and removal index.  When the removal index is
     empty it is updated to point at the current insert index.
   - Don't remove and re-add a thread to the runq when it is being adjusted
     down in priority.
   - Pull some conditional code out of sched_tick().  It's looking a bit
     large now.
  
  Revision  Changes    Path
  1.173     +52 -22    src/sys/kern/sched_ule.c
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