Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Avoid creating superfluous NUMA domains on non-NUMA systems
  sched: Allow for overlapping sched_domain spans
  sched: Break out cpu_power from the sched_group structure

4 files changed, 190 insertions, 61 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 496770a96487..bde99d5358dc 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -844,6 +844,7 @@ enum cpu_idle_type {
 #define SD_SERIALIZE            0x0400  /* Only a single load balancing instance */
 #define SD_ASYM_PACKING         0x0800  /* Place busy groups earlier in the domain */
 #define SD_PREFER_SIBLING       0x1000  /* Prefer to place tasks in a sibling domain */
+#define SD_OVERLAP              0x2000  /* sched_domains of this level overlap */
 
 enum powersavings_balance_level {
         POWERSAVINGS_BALANCE_NONE = 0,  /* No power saving load balance */
@@ -893,16 +894,21 @@ static inline int sd_power_saving_flags(void)
         return 0;
 }
 
-struct sched_group {
-        struct sched_group *next;       /* Must be a circular list */
+struct sched_group_power {
         atomic_t ref;
-
         /*
          * CPU power of this group, SCHED_LOAD_SCALE being max power for a
          * single CPU.
          */
-        unsigned int cpu_power, cpu_power_orig;
+        unsigned int power, power_orig;
+};
+
+struct sched_group {
+        struct sched_group *next;       /* Must be a circular list */
+        atomic_t ref;
+
         unsigned int group_weight;
+        struct sched_group_power *sgp;
 
         /*
          * The CPUs this group covers.
diff --git a/kernel/sched.c b/kernel/sched.c
index 3dc716f6d8ad..14168c49a154 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -6557,7 +6557,7 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                         break;
                 }
 
-                if (!group->cpu_power) {
+                if (!group->sgp->power) {
                         printk(KERN_CONT "\n");
                         printk(KERN_ERR "ERROR: domain->cpu_power not "
                                         "set\n");
@@ -6581,9 +6581,9 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                 cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
 
                 printk(KERN_CONT " %s", str);
-                if (group->cpu_power != SCHED_POWER_SCALE) {
+                if (group->sgp->power != SCHED_POWER_SCALE) {
                         printk(KERN_CONT " (cpu_power = %d)",
-                                group->cpu_power);
+                                group->sgp->power);
                 }
 
                 group = group->next;
@@ -6774,11 +6774,39 @@ static struct root_domain *alloc_rootdomain(void)
         return rd;
 }
 
+static void free_sched_groups(struct sched_group *sg, int free_sgp)
+{
+        struct sched_group *tmp, *first;
+
+        if (!sg)
+                return;
+
+        first = sg;
+        do {
+                tmp = sg->next;
+
+                if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
+                        kfree(sg->sgp);
+
+                kfree(sg);
+                sg = tmp;
+        } while (sg != first);
+}
+
 static void free_sched_domain(struct rcu_head *rcu)
 {
         struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu);
-        if (atomic_dec_and_test(&sd->groups->ref))
+
+        /*
+         * If its an overlapping domain it has private groups, iterate and
+         * nuke them all.
+         */
+        if (sd->flags & SD_OVERLAP) {
+                free_sched_groups(sd->groups, 1);
+        } else if (atomic_dec_and_test(&sd->groups->ref)) {
+                kfree(sd->groups->sgp);
                 kfree(sd->groups);
+        }
         kfree(sd);
 }
 
@@ -6945,6 +6973,7 @@ int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
 struct sd_data {
         struct sched_domain **__percpu sd;
         struct sched_group **__percpu sg;
+        struct sched_group_power **__percpu sgp;
 };
 
 struct s_data {
@@ -6964,15 +6993,73 @@ struct sched_domain_topology_level;
 typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu);
 typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
 
+#define SDTL_OVERLAP    0x01
+
 struct sched_domain_topology_level {
         sched_domain_init_f init;
         sched_domain_mask_f mask;
+        int                 flags;
         struct sd_data      data;
 };
 
-/*
- * Assumes the sched_domain tree is fully constructed
- */
+static int
+build_overlap_sched_groups(struct sched_domain *sd, int cpu)
+{
+        struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
+        const struct cpumask *span = sched_domain_span(sd);
+        struct cpumask *covered = sched_domains_tmpmask;
+        struct sd_data *sdd = sd->private;
+        struct sched_domain *child;
+        int i;
+
+        cpumask_clear(covered);
+
+        for_each_cpu(i, span) {
+                struct cpumask *sg_span;
+
+                if (cpumask_test_cpu(i, covered))
+                        continue;
+
+                sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
+                                GFP_KERNEL, cpu_to_node(i));
+
+                if (!sg)
+                        goto fail;
+
+                sg_span = sched_group_cpus(sg);
+
+                child = *per_cpu_ptr(sdd->sd, i);
+                if (child->child) {
+                        child = child->child;
+                        cpumask_copy(sg_span, sched_domain_span(child));
+                } else
+                        cpumask_set_cpu(i, sg_span);
+
+                cpumask_or(covered, covered, sg_span);
+
+                sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span));
+                atomic_inc(&sg->sgp->ref);
+
+                if (cpumask_test_cpu(cpu, sg_span))
+                        groups = sg;
+
+                if (!first)
+                        first = sg;
+                if (last)
+                        last->next = sg;
+                last = sg;
+                last->next = first;
+        }
+        sd->groups = groups;
+
+        return 0;
+
+fail:
+        free_sched_groups(first, 0);
+
+        return -ENOMEM;
+}
+
 static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
 {
         struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
@@ -6981,24 +7068,24 @@ static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
         if (child)
                 cpu = cpumask_first(sched_domain_span(child));
 
-        if (sg)
+        if (sg) {
                 *sg = *per_cpu_ptr(sdd->sg, cpu);
+                (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
+                atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
+        }
 
         return cpu;
 }
 
 /*
- * build_sched_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_cpu_ids
- * (due to the fact that we keep track of groups covered with a struct cpumask).
- *
  * build_sched_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.
+ *
+ * Assumes the sched_domain tree is fully constructed
  */
-static void
-build_sched_groups(struct sched_domain *sd)
+static int
+build_sched_groups(struct sched_domain *sd, int cpu)
 {
         struct sched_group *first = NULL, *last = NULL;
         struct sd_data *sdd = sd->private;
@@ -7006,6 +7093,12 @@ build_sched_groups(struct sched_domain *sd)
         struct cpumask *covered;
         int i;
 
+        get_group(cpu, sdd, &sd->groups);
+        atomic_inc(&sd->groups->ref);
+
+        if (cpu != cpumask_first(sched_domain_span(sd)))
+                return 0;
+
         lockdep_assert_held(&sched_domains_mutex);
         covered = sched_domains_tmpmask;
 
@@ -7020,7 +7113,7 @@ build_sched_groups(struct sched_domain *sd)
                         continue;
 
                 cpumask_clear(sched_group_cpus(sg));
-                sg->cpu_power = 0;
+                sg->sgp->power = 0;
 
                 for_each_cpu(j, span) {
                         if (get_group(j, sdd, NULL) != group)
@@ -7037,6 +7130,8 @@ build_sched_groups(struct sched_domain *sd)
                 last = sg;
         }
         last->next = first;
+
+        return 0;
 }
 
 /*
@@ -7051,12 +7146,17 @@ build_sched_groups(struct sched_domain *sd)
  */
 static void init_sched_groups_power(int cpu, struct sched_domain *sd)
 {
-        WARN_ON(!sd || !sd->groups);
+        struct sched_group *sg = sd->groups;
 
-        if (cpu != group_first_cpu(sd->groups))
-                return;
+        WARN_ON(!sd || !sg);
 
-        sd->groups->group_weight = cpumask_weight(sched_group_cpus(sd->groups));
+        do {
+                sg->group_weight = cpumask_weight(sched_group_cpus(sg));
+                sg = sg->next;
+        } while (sg != sd->groups);
+
+        if (cpu != group_first_cpu(sg))
+                return;
 
         update_group_power(sd, cpu);
 }
@@ -7177,15 +7277,15 @@ static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
 static void claim_allocations(int cpu, struct sched_domain *sd)
 {
         struct sd_data *sdd = sd->private;
-        struct sched_group *sg = sd->groups;
 
         WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
         *per_cpu_ptr(sdd->sd, cpu) = NULL;
 
-        if (cpu == cpumask_first(sched_group_cpus(sg))) {
-                WARN_ON_ONCE(*per_cpu_ptr(sdd->sg, cpu) != sg);
+        if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
                 *per_cpu_ptr(sdd->sg, cpu) = NULL;
-        }
+
+        if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
+                *per_cpu_ptr(sdd->sgp, cpu) = NULL;
 }
 
 #ifdef CONFIG_SCHED_SMT
@@ -7210,7 +7310,7 @@ static struct sched_domain_topology_level default_topology[] = {
 #endif
         { sd_init_CPU, cpu_cpu_mask, },
 #ifdef CONFIG_NUMA
-        { sd_init_NODE, cpu_node_mask, },
+        { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, },
         { sd_init_ALLNODES, cpu_allnodes_mask, },
 #endif
         { NULL, },
@@ -7234,9 +7334,14 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
                 if (!sdd->sg)
                         return -ENOMEM;
 
+                sdd->sgp = alloc_percpu(struct sched_group_power *);
+                if (!sdd->sgp)
+                        return -ENOMEM;
+
                 for_each_cpu(j, cpu_map) {
                         struct sched_domain *sd;
                         struct sched_group *sg;
+                        struct sched_group_power *sgp;
 
                         sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
                                         GFP_KERNEL, cpu_to_node(j));
@@ -7251,6 +7356,13 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
                                 return -ENOMEM;
 
                         *per_cpu_ptr(sdd->sg, j) = sg;
+
+                        sgp = kzalloc_node(sizeof(struct sched_group_power),
+                                        GFP_KERNEL, cpu_to_node(j));
+                        if (!sgp)
+                                return -ENOMEM;
+
+                        *per_cpu_ptr(sdd->sgp, j) = sgp;
                 }
         }
 
@@ -7266,11 +7378,15 @@ static void __sdt_free(const struct cpumask *cpu_map)
                 struct sd_data *sdd = &tl->data;
 
                 for_each_cpu(j, cpu_map) {
-                        kfree(*per_cpu_ptr(sdd->sd, j));
+                        struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j);
+                        if (sd && (sd->flags & SD_OVERLAP))
+                                free_sched_groups(sd->groups, 0);
                         kfree(*per_cpu_ptr(sdd->sg, j));
+                        kfree(*per_cpu_ptr(sdd->sgp, j));
                 }
                 free_percpu(sdd->sd);
                 free_percpu(sdd->sg);
+                free_percpu(sdd->sgp);
         }
 }
 
@@ -7316,8 +7432,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
                 struct sched_domain_topology_level *tl;
 
                 sd = NULL;
-                for (tl = sched_domain_topology; tl->init; tl++)
+                for (tl = sched_domain_topology; tl->init; tl++) {
                         sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
+                        if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
+                                sd->flags |= SD_OVERLAP;
+                        if (cpumask_equal(cpu_map, sched_domain_span(sd)))
+                                break;
+                }
 
                 while (sd->child)
                         sd = sd->child;
@@ -7329,13 +7450,13 @@ static int build_sched_domains(const struct cpumask *cpu_map,
         for_each_cpu(i, cpu_map) {
                 for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
                         sd->span_weight = cpumask_weight(sched_domain_span(sd));
-                        get_group(i, sd->private, &sd->groups);
-                        atomic_inc(&sd->groups->ref);
-
-                        if (i != cpumask_first(sched_domain_span(sd)))
-                                continue;
-
-                        build_sched_groups(sd);
+                        if (sd->flags & SD_OVERLAP) {
+                                if (build_overlap_sched_groups(sd, i))
+                                        goto error;
+                        } else {
+                                if (build_sched_groups(sd, i))
+                                        goto error;
+                        }
                 }
         }
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 433491c2dc8f..c768588e180b 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1585,7 +1585,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
                 }
 
                 /* Adjust by relative CPU power of the group */
-                avg_load = (avg_load * SCHED_POWER_SCALE) / group->cpu_power;
+                avg_load = (avg_load * SCHED_POWER_SCALE) / group->sgp->power;
 
                 if (local_group) {
                         this_load = avg_load;
@@ -2631,7 +2631,7 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
                 power >>= SCHED_POWER_SHIFT;
         }
 
-        sdg->cpu_power_orig = power;
+        sdg->sgp->power_orig = power;
 
         if (sched_feat(ARCH_POWER))
                 power *= arch_scale_freq_power(sd, cpu);
@@ -2647,7 +2647,7 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
                 power = 1;
 
         cpu_rq(cpu)->cpu_power = power;
-        sdg->cpu_power = power;
+        sdg->sgp->power = power;
 }
 
 static void update_group_power(struct sched_domain *sd, int cpu)
@@ -2665,11 +2665,11 @@ static void update_group_power(struct sched_domain *sd, int cpu)
 
         group = child->groups;
         do {
-                power += group->cpu_power;
+                power += group->sgp->power;
                 group = group->next;
         } while (group != child->groups);
 
-        sdg->cpu_power = power;
+        sdg->sgp->power = power;
 }
 
 /*
@@ -2691,7 +2691,7 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
         /*
          * If ~90% of the cpu_power is still there, we're good.
          */
-        if (group->cpu_power * 32 > group->cpu_power_orig * 29)
+        if (group->sgp->power * 32 > group->sgp->power_orig * 29)
                 return 1;
 
         return 0;
@@ -2771,7 +2771,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
         }
 
         /* Adjust by relative CPU power of the group */
-        sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / group->cpu_power;
+        sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / group->sgp->power;
 
         /*
          * Consider the group unbalanced when the imbalance is larger
@@ -2788,7 +2788,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
         if ((max_cpu_load - min_cpu_load) >= avg_load_per_task && max_nr_running > 1)
                 sgs->group_imb = 1;
 
-        sgs->group_capacity = DIV_ROUND_CLOSEST(group->cpu_power,
+        sgs->group_capacity = DIV_ROUND_CLOSEST(group->sgp->power,
                                                 SCHED_POWER_SCALE);
         if (!sgs->group_capacity)
                 sgs->group_capacity = fix_small_capacity(sd, group);
@@ -2877,7 +2877,7 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
                         return;
 
                 sds->total_load += sgs.group_load;
-                sds->total_pwr += sg->cpu_power;
+                sds->total_pwr += sg->sgp->power;
 
                 /*
                  * In case the child domain prefers tasks go to siblings
@@ -2962,7 +2962,7 @@ static int check_asym_packing(struct sched_domain *sd,
         if (this_cpu > busiest_cpu)
                 return 0;
 
-        *imbalance = DIV_ROUND_CLOSEST(sds->max_load * sds->busiest->cpu_power,
+        *imbalance = DIV_ROUND_CLOSEST(sds->max_load * sds->busiest->sgp->power,
                                        SCHED_POWER_SCALE);
         return 1;
 }
@@ -2993,7 +2993,7 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
 
         scaled_busy_load_per_task = sds->busiest_load_per_task
                                          * SCHED_POWER_SCALE;
-        scaled_busy_load_per_task /= sds->busiest->cpu_power;
+        scaled_busy_load_per_task /= sds->busiest->sgp->power;
 
         if (sds->max_load - sds->this_load + scaled_busy_load_per_task >=
                         (scaled_busy_load_per_task * imbn)) {
@@ -3007,28 +3007,28 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
          * moving them.
          */
 
-        pwr_now += sds->busiest->cpu_power *
+        pwr_now += sds->busiest->sgp->power *
                         min(sds->busiest_load_per_task, sds->max_load);
-        pwr_now += sds->this->cpu_power *
+        pwr_now += sds->this->sgp->power *
                         min(sds->this_load_per_task, sds->this_load);
         pwr_now /= SCHED_POWER_SCALE;
 
         /* Amount of load we'd subtract */
         tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
-                sds->busiest->cpu_power;
+                sds->busiest->sgp->power;
         if (sds->max_load > tmp)
-                pwr_move += sds->busiest->cpu_power *
+                pwr_move += sds->busiest->sgp->power *
                         min(sds->busiest_load_per_task, sds->max_load - tmp);
 
         /* Amount of load we'd add */
-        if (sds->max_load * sds->busiest->cpu_power <
+        if (sds->max_load * sds->busiest->sgp->power <
                 sds->busiest_load_per_task * SCHED_POWER_SCALE)
-                tmp = (sds->max_load * sds->busiest->cpu_power) /
-                        sds->this->cpu_power;
+                tmp = (sds->max_load * sds->busiest->sgp->power) /
+                        sds->this->sgp->power;
         else
                 tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
-                        sds->this->cpu_power;
-        pwr_move += sds->this->cpu_power *
+                        sds->this->sgp->power;
+        pwr_move += sds->this->sgp->power *
                         min(sds->this_load_per_task, sds->this_load + tmp);
         pwr_move /= SCHED_POWER_SCALE;
 
@@ -3074,7 +3074,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
 
                 load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE);
 
-                load_above_capacity /= sds->busiest->cpu_power;
+                load_above_capacity /= sds->busiest->sgp->power;
         }
 
         /*
@@ -3090,8 +3090,8 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
         max_pull = min(sds->max_load - sds->avg_load, load_above_capacity);
 
         /* How much load to actually move to equalise the imbalance */
-        *imbalance = min(max_pull * sds->busiest->cpu_power,
-                (sds->avg_load - sds->this_load) * sds->this->cpu_power)
+        *imbalance = min(max_pull * sds->busiest->sgp->power,
+                (sds->avg_load - sds->this_load) * sds->this->sgp->power)
                         / SCHED_POWER_SCALE;
 
         /*
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index be40f7371ee1..1e7066d76c26 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -70,3 +70,5 @@ SCHED_FEAT(NONIRQ_POWER, 1)
  * using the scheduler IPI. Reduces rq->lock contention/bounces.
  */
 SCHED_FEAT(TTWU_QUEUE, 1)
+
+SCHED_FEAT(FORCE_SD_OVERLAP, 0)