cvs commit: src/sys/kern sched_ule.c

Jeff Roberson jeff at
Sun Mar 2 08:21:00 UTC 2008

jeff        2008-03-02 08:20:59 UTC

  FreeBSD src repository

  Modified files:
    sys/kern             sched_ule.c 
  Add support for the new cpu topology api:
   - When searching for affinity search backwards in the tree from the last
     cpu we ran on while the thread still has affinity for the group.   This
     can take advantage of knowledge of shared L2 or L3 caches among a
     group of cores.
   - When searching for the least loaded cpu find the least loaded cpu via
     the least loaded path through the tree.  This load balances system bus
     links, individual cache levels, and hyper-threaded/SMT cores.
   - Make the periodic balancer recursively balance the highest and lowest
     loaded cpu across each link.
  Add support for cpusets:
   - Convert the cpuset to a simple native cpumask_t while the kernel still
     only supports cpumask.
   - Pass the derived cpumask down through the cpu_search functions to
     restrict the result cpus.
   - Make the various steal functions resilient to failure since all threads
     can not run on all cpus any longer.
  General improvements:
   - Precisely track the lowest priority thread on every runq with
     tdq_setlowpri().  Before it was more advisory but this ended up having
     pathological behaviors.
   - Remove many #ifdef SMP conditions to simplify the code.
   - Get rid of the old cumbersome tdq_group.  This is more naturally
     expressed via the cpu_group tree.
  Sponsored by:   Nokia
  Testing by:     kris
  Revision  Changes    Path
  1.226     +443 -501  src/sys/kern/sched_ule.c

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