1. 17 Jun, 2009 2 commits
    • Li Zefan's avatar
      sched: Remove unneeded __ref tag · fd5e1b5d
      Li Zefan authored
      Those two functions no longer call alloc_bootmmem_cpumask_var(),
      so no need to tag them with __init_refok.
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      LKML-Reference: <4A35DD5B.9050106@cn.fujitsu.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      fd5e1b5d
    • Peter Zijlstra's avatar
      sched, x86: Fix cpufreq + sched_clock() TSC scaling · 84599f8a
      Peter Zijlstra authored
      For freqency dependent TSCs we only scale the cycles, we do not account
      for the discrepancy in absolute value.
      
      Our current formula is: time = cycles * mult
      
      (where mult is a function of the cpu-speed on variable tsc machines)
      
      Suppose our current cycle count is 10, and we have a multiplier of 5,
      then our time value would end up being 50.
      
      Now cpufreq comes along and changes the multiplier to say 3 or 7,
      which would result in our time being resp. 30 or 70.
      
      That means that we can observe random jumps in the time value due to
      frequency changes in both fwd and bwd direction.
      
      So what this patch does is change the formula to:
      
        time = cycles * frequency + offset
      
      And we calculate offset so that time_before == time_after, thereby
      ridding us of these jumps in time.
      
      [ Impact: fix/reduce sched_clock() jumps across frequency changing events ]
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <new-submission>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Chucked-on-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      84599f8a
  2. 15 Jun, 2009 25 commits
  3. 14 Jun, 2009 13 commits