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    Subject[patch -rt 01/17] sched: restore __cpu_power to a straight sum of power
    cpu_power is supposed to be a representation of the process capacity
    of the cpu, not a value to randomly tweak in order to affect
    placement.

    Remove the placement hacks.

    Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com>
    ---
    include/linux/sched.h | 1 +
    include/linux/topology.h | 1 +
    kernel/sched.c | 34 ++++++++++++++++++----------------
    3 files changed, 20 insertions(+), 16 deletions(-)

    Index: linux-2.6.31.4-rt14/kernel/sched.c
    ===================================================================
    --- linux-2.6.31.4-rt14.orig/kernel/sched.c 2009-10-16 08:56:17.000000000 -0400
    +++ linux-2.6.31.4-rt14/kernel/sched.c 2009-10-16 09:15:18.000000000 -0400
    @@ -8670,15 +8670,13 @@
    * there are asymmetries in the topology. If there are asymmetries, group
    * having more cpu_power will pickup more load compared to the group having
    * less cpu_power.
    - *
    - * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
    - * the maximum number of tasks a group can handle in the presence of other idle
    - * or lightly loaded groups in the same sched domain.
    */
    static void init_sched_groups_power(int cpu, struct sched_domain *sd)
    {
    struct sched_domain *child;
    struct sched_group *group;
    + long power;
    + int weight;

    WARN_ON(!sd || !sd->groups);

    @@ -8689,22 +8687,20 @@

    sd->groups->__cpu_power = 0;

    - /*
    - * For perf policy, if the groups in child domain share resources
    - * (for example cores sharing some portions of the cache hierarchy
    - * or SMT), then set this domain groups cpu_power such that each group
    - * can handle only one task, when there are other idle groups in the
    - * same sched domain.
    - */
    - if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
    - (child->flags &
    - (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
    - sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
    + if (!child) {
    + power = SCHED_LOAD_SCALE;
    + weight = cpumask_weight(sched_domain_span(sd));
    + /*
    + * SMT siblings share the power of a single core.
    + */
    + if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1)
    + power /= weight;
    + sg_inc_cpu_power(sd->groups, power);
    return;
    }

    /*
    - * add cpu_power of each child group to this groups cpu_power
    + * Add cpu_power of each child group to this groups cpu_power.
    */
    group = child->groups;
    do {
    --


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