Merge branch 'upstream' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/misc-2.6
[linux-3.10.git] / kernel / sched.c
index f41fa94d2070b5f525f59775dff0fd9b67e567f1..18b95520a2e29bdfa181aecb913f0ea50995f609 100644 (file)
@@ -4780,7 +4780,7 @@ static int sd_parent_degenerate(struct sched_domain *sd,
  * Attach the domain 'sd' to 'cpu' as its base domain.  Callers must
  * hold the hotplug lock.
  */
-void cpu_attach_domain(struct sched_domain *sd, int cpu)
+static void cpu_attach_domain(struct sched_domain *sd, int cpu)
 {
        runqueue_t *rq = cpu_rq(cpu);
        struct sched_domain *tmp;
@@ -4803,7 +4803,7 @@ void cpu_attach_domain(struct sched_domain *sd, int cpu)
 }
 
 /* cpus with isolated domains */
-cpumask_t __devinitdata cpu_isolated_map = CPU_MASK_NONE;
+static cpumask_t __devinitdata cpu_isolated_map = CPU_MASK_NONE;
 
 /* Setup the mask of cpus configured for isolated domains */
 static int __init isolated_cpu_setup(char *str)
@@ -4831,8 +4831,8 @@ __setup ("isolcpus=", isolated_cpu_setup);
  * covered by the given span, and will set each group's ->cpumask correctly,
  * and ->cpu_power to 0.
  */
-void init_sched_build_groups(struct sched_group groups[],
-                       cpumask_t span, int (*group_fn)(int cpu))
+static void init_sched_build_groups(struct sched_group groups[], cpumask_t span,
+                                   int (*group_fn)(int cpu))
 {
        struct sched_group *first = NULL, *last = NULL;
        cpumask_t covered = CPU_MASK_NONE;
@@ -4865,12 +4865,85 @@ void init_sched_build_groups(struct sched_group groups[],
        last->next = first;
 }
 
+#define SD_NODES_PER_DOMAIN 16
 
-#ifdef ARCH_HAS_SCHED_DOMAIN
-extern void build_sched_domains(const cpumask_t *cpu_map);
-extern void arch_init_sched_domains(const cpumask_t *cpu_map);
-extern void arch_destroy_sched_domains(const cpumask_t *cpu_map);
-#else
+#ifdef CONFIG_NUMA
+/**
+ * find_next_best_node - find the next node to include in a sched_domain
+ * @node: node whose sched_domain we're building
+ * @used_nodes: nodes already in the sched_domain
+ *
+ * Find the next node to include in a given scheduling domain.  Simply
+ * finds the closest node not already in the @used_nodes map.
+ *
+ * Should use nodemask_t.
+ */
+static int find_next_best_node(int node, unsigned long *used_nodes)
+{
+       int i, n, val, min_val, best_node = 0;
+
+       min_val = INT_MAX;
+
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               /* Start at @node */
+               n = (node + i) % MAX_NUMNODES;
+
+               if (!nr_cpus_node(n))
+                       continue;
+
+               /* Skip already used nodes */
+               if (test_bit(n, used_nodes))
+                       continue;
+
+               /* Simple min distance search */
+               val = node_distance(node, n);
+
+               if (val < min_val) {
+                       min_val = val;
+                       best_node = n;
+               }
+       }
+
+       set_bit(best_node, used_nodes);
+       return best_node;
+}
+
+/**
+ * sched_domain_node_span - get a cpumask for a node's sched_domain
+ * @node: node whose cpumask we're constructing
+ * @size: number of nodes to include in this span
+ *
+ * Given a node, construct a good cpumask for its sched_domain to span.  It
+ * should be one that prevents unnecessary balancing, but also spreads tasks
+ * out optimally.
+ */
+static cpumask_t sched_domain_node_span(int node)
+{
+       int i;
+       cpumask_t span, nodemask;
+       DECLARE_BITMAP(used_nodes, MAX_NUMNODES);
+
+       cpus_clear(span);
+       bitmap_zero(used_nodes, MAX_NUMNODES);
+
+       nodemask = node_to_cpumask(node);
+       cpus_or(span, span, nodemask);
+       set_bit(node, used_nodes);
+
+       for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
+               int next_node = find_next_best_node(node, used_nodes);
+               nodemask = node_to_cpumask(next_node);
+               cpus_or(span, span, nodemask);
+       }
+
+       return span;
+}
+#endif
+
+/*
+ * At the moment, CONFIG_SCHED_SMT is never defined, but leave it in so we
+ * can switch it on easily if needed.
+ */
 #ifdef CONFIG_SCHED_SMT
 static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
 static struct sched_group sched_group_cpus[NR_CPUS];
@@ -4892,36 +4965,20 @@ static int cpu_to_phys_group(int cpu)
 }
 
 #ifdef CONFIG_NUMA
-
-static DEFINE_PER_CPU(struct sched_domain, node_domains);
-static struct sched_group sched_group_nodes[MAX_NUMNODES];
-static int cpu_to_node_group(int cpu)
-{
-       return cpu_to_node(cpu);
-}
-#endif
-
-#if defined(CONFIG_SCHED_SMT) && defined(CONFIG_NUMA)
 /*
- * The domains setup code relies on siblings not spanning
- * multiple nodes. Make sure the architecture has a proper
- * siblings map:
+ * The init_sched_build_groups can't handle what we want to do with node
+ * groups, so roll our own. Now each node has its own list of groups which
+ * gets dynamically allocated.
  */
-static void check_sibling_maps(void)
-{
-       int i, j;
+static DEFINE_PER_CPU(struct sched_domain, node_domains);
+static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
 
-       for_each_online_cpu(i) {
-               for_each_cpu_mask(j, cpu_sibling_map[i]) {
-                       if (cpu_to_node(i) != cpu_to_node(j)) {
-                               printk(KERN_INFO "warning: CPU %d siblings map "
-                                       "to different node - isolating "
-                                       "them.\n", i);
-                               cpu_sibling_map[i] = cpumask_of_cpu(i);
-                               break;
-                       }
-               }
-       }
+static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
+static struct sched_group *sched_group_allnodes_bycpu[NR_CPUS];
+
+static int cpu_to_allnodes_group(int cpu)
+{
+       return cpu_to_node(cpu);
 }
 #endif
 
@@ -4929,9 +4986,24 @@ static void check_sibling_maps(void)
  * Build sched domains for a given set of cpus and attach the sched domains
  * to the individual cpus
  */
-static void build_sched_domains(const cpumask_t *cpu_map)
+void build_sched_domains(const cpumask_t *cpu_map)
 {
        int i;
+#ifdef CONFIG_NUMA
+       struct sched_group **sched_group_nodes = NULL;
+       struct sched_group *sched_group_allnodes = NULL;
+
+       /*
+        * Allocate the per-node list of sched groups
+        */
+       sched_group_nodes = kmalloc(sizeof(struct sched_group*)*MAX_NUMNODES,
+                                          GFP_ATOMIC);
+       if (!sched_group_nodes) {
+               printk(KERN_WARNING "Can not alloc sched group node list\n");
+               return;
+       }
+       sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes;
+#endif
 
        /*
         * Set up domains for cpus specified by the cpu_map.
@@ -4944,11 +5016,35 @@ static void build_sched_domains(const cpumask_t *cpu_map)
                cpus_and(nodemask, nodemask, *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(sizeof(struct sched_group)
+                                                       * MAX_NUMNODES,
+                                                 GFP_KERNEL);
+                               if (!sched_group_allnodes) {
+                                       printk(KERN_WARNING
+                                       "Can not alloc allnodes sched group\n");
+                                       break;
+                               }
+                               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);
+                       sd->groups = &sched_group_allnodes[group];
+                       p = sd;
+               } else
+                       p = NULL;
+
                sd = &per_cpu(node_domains, i);
-               group = cpu_to_node_group(i);
                *sd = SD_NODE_INIT;
-               sd->span = *cpu_map;
-               sd->groups = &sched_group_nodes[group];
+               sd->span = sched_domain_node_span(cpu_to_node(i));
+               sd->parent = p;
+               cpus_and(sd->span, sd->span, *cpu_map);
 #endif
 
                p = sd;
@@ -4973,7 +5069,7 @@ static void build_sched_domains(const cpumask_t *cpu_map)
 
 #ifdef CONFIG_SCHED_SMT
        /* Set up CPU (sibling) groups */
-       for_each_online_cpu(i) {
+       for_each_cpu_mask(i, *cpu_map) {
                cpumask_t this_sibling_map = cpu_sibling_map[i];
                cpus_and(this_sibling_map, this_sibling_map, *cpu_map);
                if (i != first_cpu(this_sibling_map))
@@ -4998,8 +5094,77 @@ static void build_sched_domains(const cpumask_t *cpu_map)
 
 #ifdef CONFIG_NUMA
        /* Set up node groups */
-       init_sched_build_groups(sched_group_nodes, *cpu_map,
-                                       &cpu_to_node_group);
+       if (sched_group_allnodes)
+               init_sched_build_groups(sched_group_allnodes, *cpu_map,
+                                       &cpu_to_allnodes_group);
+
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               /* Set up node groups */
+               struct sched_group *sg, *prev;
+               cpumask_t nodemask = node_to_cpumask(i);
+               cpumask_t domainspan;
+               cpumask_t covered = CPU_MASK_NONE;
+               int j;
+
+               cpus_and(nodemask, nodemask, *cpu_map);
+               if (cpus_empty(nodemask)) {
+                       sched_group_nodes[i] = NULL;
+                       continue;
+               }
+
+               domainspan = sched_domain_node_span(i);
+               cpus_and(domainspan, domainspan, *cpu_map);
+
+               sg = kmalloc(sizeof(struct sched_group), GFP_KERNEL);
+               sched_group_nodes[i] = sg;
+               for_each_cpu_mask(j, nodemask) {
+                       struct sched_domain *sd;
+                       sd = &per_cpu(node_domains, j);
+                       sd->groups = sg;
+                       if (sd->groups == NULL) {
+                               /* Turn off balancing if we have no groups */
+                               sd->flags = 0;
+                       }
+               }
+               if (!sg) {
+                       printk(KERN_WARNING
+                       "Can not alloc domain group for node %d\n", i);
+                       continue;
+               }
+               sg->cpu_power = 0;
+               sg->cpumask = nodemask;
+               cpus_or(covered, covered, nodemask);
+               prev = sg;
+
+               for (j = 0; j < MAX_NUMNODES; j++) {
+                       cpumask_t tmp, notcovered;
+                       int n = (i + j) % MAX_NUMNODES;
+
+                       cpus_complement(notcovered, covered);
+                       cpus_and(tmp, notcovered, *cpu_map);
+                       cpus_and(tmp, tmp, domainspan);
+                       if (cpus_empty(tmp))
+                               break;
+
+                       nodemask = node_to_cpumask(n);
+                       cpus_and(tmp, tmp, nodemask);
+                       if (cpus_empty(tmp))
+                               continue;
+
+                       sg = kmalloc(sizeof(struct sched_group), GFP_KERNEL);
+                       if (!sg) {
+                               printk(KERN_WARNING
+                               "Can not alloc domain group for node %d\n", j);
+                               break;
+                       }
+                       sg->cpu_power = 0;
+                       sg->cpumask = tmp;
+                       cpus_or(covered, covered, tmp);
+                       prev->next = sg;
+                       prev = sg;
+               }
+               prev->next = sched_group_nodes[i];
+       }
 #endif
 
        /* Calculate CPU power for physical packages and nodes */
@@ -5018,14 +5183,46 @@ static void build_sched_domains(const cpumask_t *cpu_map)
                sd->groups->cpu_power = power;
 
 #ifdef CONFIG_NUMA
-               if (i == first_cpu(sd->groups->cpumask)) {
-                       /* Only add "power" once for each physical package. */
-                       sd = &per_cpu(node_domains, i);
-                       sd->groups->cpu_power += power;
+               sd = &per_cpu(allnodes_domains, i);
+               if (sd->groups) {
+                       power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE *
+                               (cpus_weight(sd->groups->cpumask)-1) / 10;
+                       sd->groups->cpu_power = power;
                }
 #endif
        }
 
+#ifdef CONFIG_NUMA
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               struct sched_group *sg = sched_group_nodes[i];
+               int j;
+
+               if (sg == NULL)
+                       continue;
+next_sg:
+               for_each_cpu_mask(j, sg->cpumask) {
+                       struct sched_domain *sd;
+                       int power;
+
+                       sd = &per_cpu(phys_domains, j);
+                       if (j != first_cpu(sd->groups->cpumask)) {
+                               /*
+                                * Only add "power" once for each
+                                * physical package.
+                                */
+                               continue;
+                       }
+                       power = SCHED_LOAD_SCALE + SCHED_LOAD_SCALE *
+                               (cpus_weight(sd->groups->cpumask)-1) / 10;
+
+                       sg->cpu_power += power;
+               }
+               sg = sg->next;
+               if (sg != sched_group_nodes[i])
+                       goto next_sg;
+       }
+#endif
+
        /* Attach the domains */
        for_each_cpu_mask(i, *cpu_map) {
                struct sched_domain *sd;
@@ -5040,13 +5237,10 @@ static void build_sched_domains(const cpumask_t *cpu_map)
 /*
  * Set up scheduler domains and groups.  Callers must hold the hotplug lock.
  */
-static void arch_init_sched_domains(cpumask_t *cpu_map)
+static void arch_init_sched_domains(const cpumask_t *cpu_map)
 {
        cpumask_t cpu_default_map;
 
-#if defined(CONFIG_SCHED_SMT) && defined(CONFIG_NUMA)
-       check_sibling_maps();
-#endif
        /*
         * Setup mask for cpus without special case scheduling requirements.
         * For now this just excludes isolated cpus, but could be used to
@@ -5059,10 +5253,47 @@ static void arch_init_sched_domains(cpumask_t *cpu_map)
 
 static void arch_destroy_sched_domains(const cpumask_t *cpu_map)
 {
-       /* Do nothing: everything is statically allocated. */
-}
+#ifdef CONFIG_NUMA
+       int i;
+       int cpu;
+
+       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;
+
+               for (i = 0; i < MAX_NUMNODES; i++) {
+                       cpumask_t nodemask = node_to_cpumask(i);
+                       struct sched_group *oldsg, *sg = sched_group_nodes[i];
 
-#endif /* ARCH_HAS_SCHED_DOMAIN */
+                       cpus_and(nodemask, nodemask, *cpu_map);
+                       if (cpus_empty(nodemask))
+                               continue;
+
+                       if (sg == NULL)
+                               continue;
+                       sg = sg->next;
+next_sg:
+                       oldsg = sg;
+                       sg = sg->next;
+                       kfree(oldsg);
+                       if (oldsg != sched_group_nodes[i])
+                               goto next_sg;
+               }
+               kfree(sched_group_nodes);
+               sched_group_nodes_bycpu[cpu] = NULL;
+       }
+#endif
+}
 
 /*
  * Detach sched domains from a group of cpus specified in cpu_map