1. 23 9月, 2008 4 次提交
  2. 22 9月, 2008 2 次提交
    • I
      sched: turn off WAKEUP_OVERLAP · f681bbd6
      Ingo Molnar 提交于
      WAKEUP_OVERLAP is not a winner on a 16way box, running psql+sysbench:
      
             .27-rc7-NO_WAKEUP_OVERLAP  .27-rc7-WAKEUP_OVERLAP
      -------------------------------------------------
          1:             694              811    +14.39%
          2:            1454             1427    -1.86%
          4:            3017             3070    +1.70%
          8:            5694             5808    +1.96%
         16:           10592            10612    +0.19%
         32:            9693             9647    -0.48%
         64:            8507             8262    -2.97%
        128:            8402             7087    -18.55%
        256:            8419             5124    -64.30%
        512:            7990             3671    -117.62%
      -------------------------------------------------
        SUM:           64466            55524    -16.11%
      
      ... so turn it off by default.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      f681bbd6
    • P
      sched: wakeup preempt when small overlap · 15afe09b
      Peter Zijlstra 提交于
      Lin Ming reported a 10% OLTP regression against 2.6.27-rc4.
      
      The difference seems to come from different preemption agressiveness,
      which affects the cache footprint of the workload and its effective
      cache trashing.
      
      Aggresively preempt a task if its avg overlap is very small, this should
      avoid the task going to sleep and find it still running when we schedule
      back to it - saving a wakeup.
      Reported-by: NLin Ming <ming.m.lin@intel.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      15afe09b
  3. 11 9月, 2008 1 次提交
  4. 10 9月, 2008 14 次提交
  5. 09 9月, 2008 19 次提交