sched: Simplify ->cpu_power initialization

The code in update_group_power() does what init_sched_groups_power()
does and more, so remove the special init_ code and call the generic
code instead.

Also move the sd->span_weight initialization because
update_group_power() needs it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122941.875856012@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index d3e183c85f49d81a2ea9c41bb9bee9721459c459..50d5fd33e8d5408084358d5d9b2d8e903ae62cee 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6679,9 +6679,6 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
        struct rq *rq = cpu_rq(cpu);
        struct sched_domain *tmp;
 
-       for (tmp = sd; tmp; tmp = tmp->parent)
-               tmp->span_weight = cpumask_weight(sched_domain_span(tmp));
-
        /* Remove the sched domains which do not contribute to scheduling. */
        for (tmp = sd; tmp; ) {
                struct sched_domain *parent = tmp->parent;
@@ -7159,11 +7156,6 @@ static void free_sched_groups(const struct cpumask *cpu_map,
  */
 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);
 
        if (cpu != group_first_cpu(sd->groups))
@@ -7171,36 +7163,7 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
 
        sd->groups->group_weight = cpumask_weight(sched_group_cpus(sd->groups));
 
-       child = sd->child;
-
-       sd->groups->cpu_power = 0;
-
-       if (!child) {
-               power = SCHED_LOAD_SCALE;
-               weight = cpumask_weight(sched_domain_span(sd));
-               /*
-                * SMT siblings share the power of a single core.
-                * Usually multiple threads get a better yield out of
-                * that one core than a single thread would have,
-                * reflect that in sd->smt_gain.
-                */
-               if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
-                       power *= sd->smt_gain;
-                       power /= weight;
-                       power >>= SCHED_LOAD_SHIFT;
-               }
-               sd->groups->cpu_power += power;
-               return;
-       }
-
-       /*
-        * Add cpu_power of each child group to this groups cpu_power.
-        */
-       group = child->groups;
-       do {
-               sd->groups->cpu_power += group->cpu_power;
-               group = group->next;
-       } while (group != child->groups);
+       update_group_power(sd, cpu);
 }
 
 /*
@@ -7507,7 +7470,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
 {
        enum s_alloc alloc_state = sa_none;
        struct s_data d;
-       struct sched_domain *sd;
+       struct sched_domain *sd, *tmp;
        int i;
 #ifdef CONFIG_NUMA
        d.sd_allnodes = 0;
@@ -7530,6 +7493,9 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
                sd = __build_book_sched_domain(&d, cpu_map, attr, sd, i);
                sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i);
                sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i);
+
+               for (tmp = sd; tmp; tmp = tmp->parent)
+                       tmp->span_weight = cpumask_weight(sched_domain_span(tmp));
        }
 
        for_each_cpu(i, cpu_map) {