1. 09 12月, 2010 1 次提交
    • P
      sched: Cure more NO_HZ load average woes · 0f004f5a
      Peter Zijlstra 提交于
      There's a long-running regression that proved difficult to fix and
      which is hitting certain people and is rather annoying in its effects.
      
      Damien reported that after 74f5187a (sched: Cure load average vs
      NO_HZ woes) his load average is unnaturally high, he also noted that
      even with that patch reverted the load avgerage numbers are not
      correct.
      
      The problem is that the previous patch only solved half the NO_HZ
      problem, it addressed the part of going into NO_HZ mode, not of
      comming out of NO_HZ mode. This patch implements that missing half.
      
      When comming out of NO_HZ mode there are two important things to take
      care of:
      
       - Folding the pending idle delta into the global active count.
       - Correctly aging the averages for the idle-duration.
      
      So with this patch the NO_HZ interaction should be complete and
      behaviour between CONFIG_NO_HZ=[yn] should be equivalent.
      
      Furthermore, this patch slightly changes the load average computation
      by adding a rounding term to the fixed point multiplication.
      Reported-by: NDamien Wyart <damien.wyart@free.fr>
      Reported-by: NTim McGrath <tmhikaru@gmail.com>
      Tested-by: NDamien Wyart <damien.wyart@free.fr>
      Tested-by: NOrion Poplawski <orion@cora.nwra.com>
      Tested-by: NKyle McMartin <kyle@mcmartin.ca>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: stable@kernel.org
      Cc: Chase Douglas <chase.douglas@canonical.com>
      LKML-Reference: <1291129145.32004.874.camel@laptop>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      0f004f5a
  2. 08 12月, 2010 18 次提交
  3. 07 12月, 2010 12 次提交
  4. 06 12月, 2010 8 次提交
  5. 05 12月, 2010 1 次提交