[patch 1/2] parameterize arch_init_sched_domains

[nathanl@austin.ibm.com]

On some systems (e.g. ppc64 partitions), we don't have topology and
associativity information for all "possible" cpus, so it doesn't make
sense to set up domains for them.  Make arch_init_sched_domains take a
cpumask_t argument, which is used instead of cpu_possible_map to set
up the domains and groups.  At boot, call arch_init_sched_domains with
the online map as argument.  This leaves offline cpus attached to the
dummy sched_domain_init domain, which should be fine.

A followup patch will handle cpus which are onlined after boot.

Signed-off-by: Nathan Lynch <nathanl@austin.ibm.com>


---


diff -puN kernel/sched.c~parameterize-arch_init_sched_domains kernel/sched.c
--- 2.6.9-rc1-bk14/kernel/sched.c~parameterize-arch_init_sched_domains	2004-09-07 13:02:39.000000000 -0500
+++ 2.6.9-rc1-bk14-nathanl/kernel/sched.c	2004-09-07 13:29:51.000000000 -0500
@@ -4394,21 +4394,19 @@ __init static void init_sched_build_grou
 	last->next = first;
 }
 
-__init static void arch_init_sched_domains(void)
+__init static void arch_init_sched_domains(cpumask_t cpu_default_map)
 {
 	int i;
-	cpumask_t cpu_default_map;
-
 	/*
 	 * Setup mask for cpus without special case scheduling requirements.
 	 * For now this just excludes isolated cpus, but could be used to
 	 * exclude other special cases in the future.
 	 */
-	cpus_complement(cpu_default_map, cpu_isolated_map);
-	cpus_and(cpu_default_map, cpu_default_map, cpu_possible_map);
+	for_each_cpu_mask(i, cpu_isolated_map)
+		cpu_clear(i, cpu_default_map);
 
 	/* Set up domains */
-	for_each_cpu(i) {
+	for_each_cpu_mask(i, cpu_default_map) {
 		int group;
 		struct sched_domain *sd = NULL, *p;
 		cpumask_t nodemask = node_to_cpumask(cpu_to_node(i));
@@ -4454,7 +4452,7 @@ __init static void arch_init_sched_domai
 #ifdef CONFIG_NUMA
 		sd->span = nodemask;
 #else
-		sd->span = cpu_possible_map;
+		sd->span = cpu_default_map;
 #endif
 		sd->parent = p;
 		sd->groups = &sched_group_phys[group];
@@ -4473,7 +4471,7 @@ __init static void arch_init_sched_domai
 
 #ifdef CONFIG_SCHED_SMT
 	/* Set up CPU (sibling) groups */
-	for_each_cpu(i) {
+	for_each_cpu_mask(i, cpu_default_map) {
 		cpumask_t this_sibling_map = cpu_sibling_map[i];
 		cpus_and(this_sibling_map, this_sibling_map, cpu_default_map);
 		if (i != first_cpu(this_sibling_map))
@@ -4506,7 +4504,7 @@ __init static void arch_init_sched_domai
 						&cpu_to_phys_group);
 	}
 #else
-	init_sched_build_groups(sched_group_phys, cpu_possible_map,
+	init_sched_build_groups(sched_group_phys, cpu_default_map,
 							&cpu_to_phys_group);
 #endif
 
@@ -4541,7 +4539,7 @@ __init static void arch_init_sched_domai
 	}
 
 	/* Attach the domains */
-	for_each_cpu(i) {
+	for_each_cpu_mask(i, cpu_default_map) {
 		struct sched_domain *sd;
 #ifdef CONFIG_SCHED_SMT
 		sd = &per_cpu(cpu_domains, i);
@@ -4634,7 +4632,7 @@ void sched_domain_debug(void)
 
 void __init sched_init_smp(void)
 {
-	arch_init_sched_domains();
+	arch_init_sched_domains(cpu_online_map);
 	sched_domain_debug();
 }
 #else

_