1. 16 9月, 2009 1 次提交
  2. 15 9月, 2009 1 次提交
    • P
      x86: sched: Provide arch implementations using aperf/mperf · 47fe38fc
      Peter Zijlstra 提交于
      APERF/MPERF support for cpu_power.
      
      APERF/MPERF is arch defined to be a relative scale of work capacity
      per logical cpu, this is assumed to include SMT and Turbo mode.
      
      APERF/MPERF are specified to both reset to 0 when either counter
      wraps, which is highly inconvenient, since that'll give a blimp
      when that happens. The manual specifies writing 0 to the counters
      after each read, but that's 1) too expensive, and 2) destroys the
      possibility of sharing these counters with other users, so we live
      with the blimp - the other existing user does too.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      47fe38fc