sched: Reverse the topology list

In order to get rid of static sched_domain::level assignments, reverse
the topology iteration.

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/20110407122942.876506131@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 20 insertions, 14 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 00d1e37b4596..38bc53b576a7 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7114,20 +7114,23 @@ static const struct cpumask *cpu_smt_mask(int cpu)
 }
 #endif
 
+/*
+ * Topology list, bottom-up.
+ */
 static struct sched_domain_topology_level default_topology[] = {
-#ifdef CONFIG_NUMA
-        { sd_init_ALLNODES, cpu_allnodes_mask, },
-        { sd_init_NODE, cpu_node_mask, },
-#endif
-        { sd_init_CPU, cpu_cpu_mask, },
-#ifdef CONFIG_SCHED_BOOK
-        { sd_init_BOOK, cpu_book_mask, },
+#ifdef CONFIG_SCHED_SMT
+        { sd_init_SIBLING, cpu_smt_mask, },
 #endif
 #ifdef CONFIG_SCHED_MC
         { sd_init_MC, cpu_coregroup_mask, },
 #endif
-#ifdef CONFIG_SCHED_SMT
-        { sd_init_SIBLING, cpu_smt_mask, },
+#ifdef CONFIG_SCHED_BOOK
+        { sd_init_BOOK, cpu_book_mask, },
+#endif
+        { sd_init_CPU, cpu_cpu_mask, },
+#ifdef CONFIG_NUMA
+        { sd_init_NODE, cpu_node_mask, },
+        { sd_init_ALLNODES, cpu_allnodes_mask, },
 #endif
         { NULL, },
 };
@@ -7136,18 +7139,18 @@ static struct sched_domain_topology_level *sched_domain_topology = default_topol
 
 struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
                 struct s_data *d, const struct cpumask *cpu_map,
-                struct sched_domain_attr *attr, struct sched_domain *parent,
+                struct sched_domain_attr *attr, struct sched_domain *child,
                 int cpu)
 {
         struct sched_domain *sd = tl->init(d, cpu);
         if (!sd)
-                return parent;
+                return child;
 
         set_domain_attribute(sd, attr);
         cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
-        sd->parent = parent;
-        if (parent)
-                parent->child = sd;
+        if (child)
+                child->parent = sd;
+        sd->child = child;
 
         return sd;
 }
@@ -7176,6 +7179,9 @@ static int build_sched_domains(const struct cpumask *cpu_map,
                 for (tl = sched_domain_topology; tl->init; tl++)
                         sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
 
+                while (sd->child)
+                        sd = sd->child;
+
                 *per_cpu_ptr(d.sd, i) = sd;
         }