[PATCH] ched domain: move sched group allocations to percpu area

Move the sched group allocations to percpu area.  This will minimize cross
node memory references and also cleans up the sched groups allocation for
allnodes sched domain.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/sched.c

@@ -5528,28 +5528,27 @@ static int __init isolated_cpu_setup(char *str)
 __setup ("isolcpus=", isolated_cpu_setup);
 
 /*
- * init_sched_build_groups takes an array of groups, the cpumask we wish
- * to span, and a pointer to a function which identifies what group a CPU
- * belongs to. The return value of group_fn must be a valid index into the
- * groups[] array, and must be >= 0 and < NR_CPUS (due to the fact that we
- * keep track of groups covered with a cpumask_t).
+ * init_sched_build_groups takes the cpumask we wish to span, and a pointer
+ * to a function which identifies what group(along with sched group) a CPU
+ * belongs to. The return value of group_fn must be a >= 0 and < NR_CPUS
+ * (due to the fact that we keep track of groups covered with a cpumask_t).
  *
  * init_sched_build_groups will build a circular linked list of the groups
  * covered by the given span, and will set each group's ->cpumask correctly,
  * and ->cpu_power to 0.
  */
 static void
-init_sched_build_groups(struct sched_group groups[], cpumask_t span,
-			const cpumask_t *cpu_map,
-			int (*group_fn)(int cpu, const cpumask_t *cpu_map))
+init_sched_build_groups(cpumask_t span, const cpumask_t *cpu_map,
+			int (*group_fn)(int cpu, const cpumask_t *cpu_map,
+					struct sched_group **sg))
 {
 	struct sched_group *first = NULL, *last = NULL;
 	cpumask_t covered = CPU_MASK_NONE;
 	int i;
 
 	for_each_cpu_mask(i, span) {
-		int group = group_fn(i, cpu_map);
-		struct sched_group *sg = &groups[group];
+		struct sched_group *sg;
+		int group = group_fn(i, cpu_map, &sg);
 		int j;
 
 		if (cpu_isset(i, covered))
@@ -5559,7 +5558,7 @@ init_sched_build_groups(struct sched_group groups[], cpumask_t span,
 		sg->cpu_power = 0;
 
 		for_each_cpu_mask(j, span) {
-			if (group_fn(j, cpu_map) != group)
+			if (group_fn(j, cpu_map, NULL) != group)
 				continue;
 
 			cpu_set(j, covered);
@@ -6135,10 +6134,13 @@ int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
  */
 #ifdef CONFIG_SCHED_SMT
 static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
-static struct sched_group sched_group_cpus[NR_CPUS];
+static DEFINE_PER_CPU(struct sched_group, sched_group_cpus);
 
-static int cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map)
+static int cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map,
+			    struct sched_group **sg)
 {
+	if (sg)
+		*sg = &per_cpu(sched_group_cpus, cpu);
 	return cpu;
 }
 #endif
@@ -6148,39 +6150,52 @@ static int cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map)
  */
 #ifdef CONFIG_SCHED_MC
 static DEFINE_PER_CPU(struct sched_domain, core_domains);
-static struct sched_group sched_group_core[NR_CPUS];
+static DEFINE_PER_CPU(struct sched_group, sched_group_core);
 #endif
 
 #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
-static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map)
+static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map,
+			     struct sched_group **sg)
 {
+	int group;
 	cpumask_t mask = cpu_sibling_map[cpu];
 	cpus_and(mask, mask, *cpu_map);
-	return first_cpu(mask);
+	group = first_cpu(mask);
+	if (sg)
+		*sg = &per_cpu(sched_group_core, group);
+	return group;
 }
 #elif defined(CONFIG_SCHED_MC)
-static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map)
+static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map,
+			     struct sched_group **sg)
 {
+	if (sg)
+		*sg = &per_cpu(sched_group_core, cpu);
 	return cpu;
 }
 #endif
 
 static DEFINE_PER_CPU(struct sched_domain, phys_domains);
-static struct sched_group sched_group_phys[NR_CPUS];
+static DEFINE_PER_CPU(struct sched_group, sched_group_phys);
 
-static int cpu_to_phys_group(int cpu, const cpumask_t *cpu_map)
+static int cpu_to_phys_group(int cpu, const cpumask_t *cpu_map,
+			     struct sched_group **sg)
 {
+	int group;
 #ifdef CONFIG_SCHED_MC
 	cpumask_t mask = cpu_coregroup_map(cpu);
 	cpus_and(mask, mask, *cpu_map);
-	return first_cpu(mask);
+	group = first_cpu(mask);
 #elif defined(CONFIG_SCHED_SMT)
 	cpumask_t mask = cpu_sibling_map[cpu];
 	cpus_and(mask, mask, *cpu_map);
-	return first_cpu(mask);
+	group = first_cpu(mask);
 #else
-	return cpu;
+	group = cpu;
 #endif
+	if (sg)
+		*sg = &per_cpu(sched_group_phys, group);
+	return group;
 }
 
 #ifdef CONFIG_NUMA
@@ -6193,12 +6208,22 @@ static DEFINE_PER_CPU(struct sched_domain, node_domains);
 static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
 
 static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
-static struct sched_group *sched_group_allnodes_bycpu[NR_CPUS];
+static DEFINE_PER_CPU(struct sched_group, sched_group_allnodes);
 
-static int cpu_to_allnodes_group(int cpu, const cpumask_t *cpu_map)
+static int cpu_to_allnodes_group(int cpu, const cpumask_t *cpu_map,
+				 struct sched_group **sg)
 {
-	return cpu_to_node(cpu);
+	cpumask_t nodemask = node_to_cpumask(cpu_to_node(cpu));
+	int group;
+
+	cpus_and(nodemask, nodemask, *cpu_map);
+	group = first_cpu(nodemask);
+
+	if (sg)
+		*sg = &per_cpu(sched_group_allnodes, group);
+	return group;
 }
+
 static void init_numa_sched_groups_power(struct sched_group *group_head)
 {
 	struct sched_group *sg = group_head;
@@ -6234,16 +6259,9 @@ static void free_sched_groups(const cpumask_t *cpu_map)
 	int cpu, i;
 
 	for_each_cpu_mask(cpu, *cpu_map) {
-		struct sched_group *sched_group_allnodes
-			= sched_group_allnodes_bycpu[cpu];
 		struct sched_group **sched_group_nodes
 			= sched_group_nodes_bycpu[cpu];
 
-		if (sched_group_allnodes) {
-			kfree(sched_group_allnodes);
-			sched_group_allnodes_bycpu[cpu] = NULL;
-		}
-
 		if (!sched_group_nodes)
 			continue;
 
@@ -6337,7 +6355,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 	struct sched_domain *sd;
 #ifdef CONFIG_NUMA
 	struct sched_group **sched_group_nodes = NULL;
-	struct sched_group *sched_group_allnodes = NULL;
+	int sd_allnodes = 0;
 
 	/*
 	 * Allocate the per-node list of sched groups
@@ -6355,7 +6373,6 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 	 * Set up domains for cpus specified by the cpu_map.
 	 */
 	for_each_cpu_mask(i, *cpu_map) {
-		int group;
 		struct sched_domain *sd = NULL, *p;
 		cpumask_t nodemask = node_to_cpumask(cpu_to_node(i));
 
@@ -6364,26 +6381,12 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 #ifdef CONFIG_NUMA
 		if (cpus_weight(*cpu_map)
 				> SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) {
-			if (!sched_group_allnodes) {
-				sched_group_allnodes
-					= kmalloc_node(sizeof(struct sched_group)
-						  	* MAX_NUMNODES,
-						  GFP_KERNEL,
-						  cpu_to_node(i));
-				if (!sched_group_allnodes) {
-					printk(KERN_WARNING
-					"Can not alloc allnodes sched group\n");
-					goto error;
-				}
-				sched_group_allnodes_bycpu[i]
-						= sched_group_allnodes;
-			}
 			sd = &per_cpu(allnodes_domains, i);
 			*sd = SD_ALLNODES_INIT;
 			sd->span = *cpu_map;
-			group = cpu_to_allnodes_group(i, cpu_map);
-			sd->groups = &sched_group_allnodes[group];
+			cpu_to_allnodes_group(i, cpu_map, &sd->groups);
 			p = sd;
+			sd_allnodes = 1;
 		} else
 			p = NULL;
 
@@ -6398,36 +6401,33 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 
 		p = sd;
 		sd = &per_cpu(phys_domains, i);
-		group = cpu_to_phys_group(i, cpu_map);
 		*sd = SD_CPU_INIT;
 		sd->span = nodemask;
 		sd->parent = p;
 		if (p)
 			p->child = sd;
-		sd->groups = &sched_group_phys[group];
+		cpu_to_phys_group(i, cpu_map, &sd->groups);
 
 #ifdef CONFIG_SCHED_MC
 		p = sd;
 		sd = &per_cpu(core_domains, i);
-		group = cpu_to_core_group(i, cpu_map);
 		*sd = SD_MC_INIT;
 		sd->span = cpu_coregroup_map(i);
 		cpus_and(sd->span, sd->span, *cpu_map);
 		sd->parent = p;
 		p->child = sd;
-		sd->groups = &sched_group_core[group];
+		cpu_to_core_group(i, cpu_map, &sd->groups);
 #endif
 
 #ifdef CONFIG_SCHED_SMT
 		p = sd;
 		sd = &per_cpu(cpu_domains, i);
-		group = cpu_to_cpu_group(i, cpu_map);
 		*sd = SD_SIBLING_INIT;
 		sd->span = cpu_sibling_map[i];
 		cpus_and(sd->span, sd->span, *cpu_map);
 		sd->parent = p;
 		p->child = sd;
-		sd->groups = &sched_group_cpus[group];
+		cpu_to_cpu_group(i, cpu_map, &sd->groups);
 #endif
 	}
 
@@ -6439,8 +6439,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 		if (i != first_cpu(this_sibling_map))
 			continue;
 
-		init_sched_build_groups(sched_group_cpus, this_sibling_map,
-					cpu_map, &cpu_to_cpu_group);
+		init_sched_build_groups(this_sibling_map, cpu_map, &cpu_to_cpu_group);
 	}
 #endif
 
@@ -6451,8 +6450,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 		cpus_and(this_core_map, this_core_map, *cpu_map);
 		if (i != first_cpu(this_core_map))
 			continue;
-		init_sched_build_groups(sched_group_core, this_core_map,
-					cpu_map, &cpu_to_core_group);
+		init_sched_build_groups(this_core_map, cpu_map, &cpu_to_core_group);
 	}
 #endif
 
@@ -6465,15 +6463,13 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 		if (cpus_empty(nodemask))
 			continue;
 
-		init_sched_build_groups(sched_group_phys, nodemask,
-					cpu_map, &cpu_to_phys_group);
+		init_sched_build_groups(nodemask, cpu_map, &cpu_to_phys_group);
 	}
 
 #ifdef CONFIG_NUMA
 	/* Set up node groups */
-	if (sched_group_allnodes)
-		init_sched_build_groups(sched_group_allnodes, *cpu_map,
-					cpu_map, &cpu_to_allnodes_group);
+	if (sd_allnodes)
+		init_sched_build_groups(*cpu_map, cpu_map, &cpu_to_allnodes_group);
 
 	for (i = 0; i < MAX_NUMNODES; i++) {
 		/* Set up node groups */
@@ -6565,10 +6561,10 @@ static int build_sched_domains(const cpumask_t *cpu_map)
 	for (i = 0; i < MAX_NUMNODES; i++)
 		init_numa_sched_groups_power(sched_group_nodes[i]);
 
-	if (sched_group_allnodes) {
-		int group = cpu_to_allnodes_group(first_cpu(*cpu_map), cpu_map);
-		struct sched_group *sg = &sched_group_allnodes[group];
+	if (sd_allnodes) {
+		struct sched_group *sg;
 
+		cpu_to_allnodes_group(first_cpu(*cpu_map), cpu_map, &sg);
 		init_numa_sched_groups_power(sg);
 	}
 #endif