sched: Simplify NODE/ALLNODES domain creation

Don't treat ALLNODES/NODE different for difference's sake. Simply
always create the ALLNODES domain and let the sd_degenerate() checks
kill it when its redundant. This simplifies the code flow.

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/20110407122942.455464579@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index 72c194c..d395fe5 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6838,9 +6838,6 @@ struct sd_data {
 };
 
 struct s_data {
-#ifdef CONFIG_NUMA
-       int                     sd_allnodes;
-#endif
        cpumask_var_t           nodemask;
        cpumask_var_t           send_covered;
        struct sched_domain ** __percpu sd;
@@ -7112,30 +7109,35 @@ static void claim_allocations(int cpu, struct sched_domain *sd)
        }
 }
 
-static struct sched_domain *__build_numa_sched_domains(struct s_data *d,
-       const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i)
+static struct sched_domain *__build_allnodes_sched_domain(struct s_data *d,
+       const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+       struct sched_domain *parent, int i)
 {
        struct sched_domain *sd = NULL;
 #ifdef CONFIG_NUMA
-       struct sched_domain *parent;
-
-       d->sd_allnodes = 0;
-       if (cpumask_weight(cpu_map) >
-           SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) {
-               sd = sd_init_ALLNODES(d, i);
-               set_domain_attribute(sd, attr);
-               cpumask_copy(sched_domain_span(sd), cpu_map);
-               d->sd_allnodes = 1;
-       }
-       parent = sd;
+       sd = sd_init_ALLNODES(d, i);
+       set_domain_attribute(sd, attr);
+       cpumask_copy(sched_domain_span(sd), cpu_map);
+       sd->parent = parent;
+       if (parent)
+               parent->child = sd;
+#endif
+       return sd;
+}
 
+static struct sched_domain *__build_node_sched_domain(struct s_data *d,
+       const struct cpumask *cpu_map, struct sched_domain_attr *attr,
+       struct sched_domain *parent, int i)
+{
+       struct sched_domain *sd = NULL;
+#ifdef CONFIG_NUMA
        sd = sd_init_NODE(d, i);
        set_domain_attribute(sd, attr);
        sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
+       cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map);
        sd->parent = parent;
        if (parent)
                parent->child = sd;
-       cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map);
 #endif
        return sd;
 }
@@ -7220,7 +7222,9 @@ static int build_sched_domains(const struct cpumask *cpu_map,
                cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)),
                            cpu_map);
 
-               sd = __build_numa_sched_domains(&d, cpu_map, attr, i);
+               sd = NULL;
+               sd = __build_allnodes_sched_domain(&d, cpu_map, attr, sd, i);
+               sd = __build_node_sched_domain(&d, cpu_map, attr, sd, i);
                sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i);
                sd = __build_book_sched_domain(&d, cpu_map, attr, sd, i);
                sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i);