sched: Simplify sched_groups_power initialization

Again, instead of relying on knowing the possible domains and their
order, simply rely on the sched_domain tree and whatever domains are
present in there to initialize the sched_group cpu_power.

Note: we need to iterate the CPU mask backwards because of the
cpumask_first() condition for iterating up the tree. By iterating the
mask backwards we ensure all groups of a domain are set-up before
starting on the parent groups that rely on its children to be
completely done.

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/20110407122942.187335414@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 34 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index d6992bfa11eb..1cca59ec4a49 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7334,43 +7334,14 @@ static int __build_sched_domains(const struct cpumask *cpu_map,
         }
 
         /* Calculate CPU power for physical packages and nodes */
-#ifdef CONFIG_SCHED_SMT
-        for_each_cpu(i, cpu_map) {
-                sd = &per_cpu(cpu_domains, i).sd;
-                init_sched_groups_power(i, sd);
-        }
-#endif
-#ifdef CONFIG_SCHED_MC
-        for_each_cpu(i, cpu_map) {
-                sd = &per_cpu(core_domains, i).sd;
-                init_sched_groups_power(i, sd);
-        }
-#endif
-#ifdef CONFIG_SCHED_BOOK
-        for_each_cpu(i, cpu_map) {
-                sd = &per_cpu(book_domains, i).sd;
-                init_sched_groups_power(i, sd);
-        }
-#endif
-
-        for_each_cpu(i, cpu_map) {
-                sd = &per_cpu(phys_domains, i).sd;
-                init_sched_groups_power(i, sd);
-        }
-
-#ifdef CONFIG_NUMA
-        for_each_cpu(i, cpu_map) {
-                sd = &per_cpu(node_domains, i).sd;
-                init_sched_groups_power(i, sd);
-        }
+        for (i = nr_cpumask_bits-1; i >= 0; i--) {
+                if (!cpumask_test_cpu(i, cpu_map))
+                        continue;
 
-        if (d.sd_allnodes) {
-                for_each_cpu(i, cpu_map) {
-                        sd = &per_cpu(allnodes_domains, i).sd;
+                sd = *per_cpu_ptr(d.sd, i);
+                for (; sd; sd = sd->parent)
                         init_sched_groups_power(i, sd);
-                }
         }
-#endif
 
         /* Attach the domains */
         for_each_cpu(i, cpu_map) {