| /* |
| * Scheduler topology setup/handling methods |
| */ |
| #include <linux/sched.h> |
| #include <linux/mutex.h> |
| |
| #include "sched.h" |
| |
| DEFINE_MUTEX(sched_domains_mutex); |
| |
| /* Protected by sched_domains_mutex: */ |
| cpumask_var_t sched_domains_tmpmask; |
| cpumask_var_t sched_domains_tmpmask2; |
| |
| #ifdef CONFIG_SCHED_DEBUG |
| |
| static __read_mostly int sched_debug_enabled; |
| |
| static int __init sched_debug_setup(char *str) |
| { |
| sched_debug_enabled = 1; |
| |
| return 0; |
| } |
| early_param("sched_debug", sched_debug_setup); |
| |
| static inline bool sched_debug(void) |
| { |
| return sched_debug_enabled; |
| } |
| |
| static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
| struct cpumask *groupmask) |
| { |
| struct sched_group *group = sd->groups; |
| |
| cpumask_clear(groupmask); |
| |
| printk(KERN_DEBUG "%*s domain-%d: ", level, "", level); |
| |
| if (!(sd->flags & SD_LOAD_BALANCE)) { |
| printk("does not load-balance\n"); |
| if (sd->parent) |
| printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
| " has parent"); |
| return -1; |
| } |
| |
| printk(KERN_CONT "span=%*pbl level=%s\n", |
| cpumask_pr_args(sched_domain_span(sd)), sd->name); |
| |
| if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
| printk(KERN_ERR "ERROR: domain->span does not contain " |
| "CPU%d\n", cpu); |
| } |
| if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
| printk(KERN_ERR "ERROR: domain->groups does not contain" |
| " CPU%d\n", cpu); |
| } |
| |
| printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
| do { |
| if (!group) { |
| printk("\n"); |
| printk(KERN_ERR "ERROR: group is NULL\n"); |
| break; |
| } |
| |
| if (!cpumask_weight(sched_group_cpus(group))) { |
| printk(KERN_CONT "\n"); |
| printk(KERN_ERR "ERROR: empty group\n"); |
| break; |
| } |
| |
| if (!(sd->flags & SD_OVERLAP) && |
| cpumask_intersects(groupmask, sched_group_cpus(group))) { |
| printk(KERN_CONT "\n"); |
| printk(KERN_ERR "ERROR: repeated CPUs\n"); |
| break; |
| } |
| |
| cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
| |
| printk(KERN_CONT " %d:{ span=%*pbl", |
| group->sgc->id, |
| cpumask_pr_args(sched_group_cpus(group))); |
| |
| if ((sd->flags & SD_OVERLAP) && !cpumask_full(sched_group_mask(group))) { |
| printk(KERN_CONT " mask=%*pbl", |
| cpumask_pr_args(sched_group_mask(group))); |
| } |
| |
| if (group->sgc->capacity != SCHED_CAPACITY_SCALE) |
| printk(KERN_CONT " cap=%lu", group->sgc->capacity); |
| |
| if (group == sd->groups && sd->child && |
| !cpumask_equal(sched_domain_span(sd->child), |
| sched_group_cpus(group))) { |
| printk(KERN_ERR "ERROR: domain->groups does not match domain->child\n"); |
| } |
| |
| printk(KERN_CONT " }"); |
| |
| group = group->next; |
| |
| if (group != sd->groups) |
| printk(KERN_CONT ","); |
| |
| } while (group != sd->groups); |
| printk(KERN_CONT "\n"); |
| |
| if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
| printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
| |
| if (sd->parent && |
| !cpumask_subset(groupmask, sched_domain_span(sd->parent))) |
| printk(KERN_ERR "ERROR: parent span is not a superset " |
| "of domain->span\n"); |
| return 0; |
| } |
| |
| static void sched_domain_debug(struct sched_domain *sd, int cpu) |
| { |
| int level = 0; |
| |
| if (!sched_debug_enabled) |
| return; |
| |
| if (!sd) { |
| printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); |
| return; |
| } |
| |
| printk(KERN_DEBUG "CPU%d attaching sched-domain(s):\n", cpu); |
| |
| for (;;) { |
| if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
| break; |
| level++; |
| sd = sd->parent; |
| if (!sd) |
| break; |
| } |
| } |
| #else /* !CONFIG_SCHED_DEBUG */ |
| |
| # define sched_debug_enabled 0 |
| # define sched_domain_debug(sd, cpu) do { } while (0) |
| static inline bool sched_debug(void) |
| { |
| return false; |
| } |
| #endif /* CONFIG_SCHED_DEBUG */ |
| |
| static int sd_degenerate(struct sched_domain *sd) |
| { |
| if (cpumask_weight(sched_domain_span(sd)) == 1) |
| return 1; |
| |
| /* Following flags need at least 2 groups */ |
| if (sd->flags & (SD_LOAD_BALANCE | |
| SD_BALANCE_NEWIDLE | |
| SD_BALANCE_FORK | |
| SD_BALANCE_EXEC | |
| SD_SHARE_CPUCAPACITY | |
| SD_ASYM_CPUCAPACITY | |
| SD_SHARE_PKG_RESOURCES | |
| SD_SHARE_POWERDOMAIN)) { |
| if (sd->groups != sd->groups->next) |
| return 0; |
| } |
| |
| /* Following flags don't use groups */ |
| if (sd->flags & (SD_WAKE_AFFINE)) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int |
| sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) |
| { |
| unsigned long cflags = sd->flags, pflags = parent->flags; |
| |
| if (sd_degenerate(parent)) |
| return 1; |
| |
| if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
| return 0; |
| |
| /* Flags needing groups don't count if only 1 group in parent */ |
| if (parent->groups == parent->groups->next) { |
| pflags &= ~(SD_LOAD_BALANCE | |
| SD_BALANCE_NEWIDLE | |
| SD_BALANCE_FORK | |
| SD_BALANCE_EXEC | |
| SD_ASYM_CPUCAPACITY | |
| SD_SHARE_CPUCAPACITY | |
| SD_SHARE_PKG_RESOURCES | |
| SD_PREFER_SIBLING | |
| SD_SHARE_POWERDOMAIN); |
| if (nr_node_ids == 1) |
| pflags &= ~SD_SERIALIZE; |
| } |
| if (~cflags & pflags) |
| return 0; |
| |
| return 1; |
| } |
| |
| static void free_rootdomain(struct rcu_head *rcu) |
| { |
| struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
| |
| cpupri_cleanup(&rd->cpupri); |
| cpudl_cleanup(&rd->cpudl); |
| free_cpumask_var(rd->dlo_mask); |
| free_cpumask_var(rd->rto_mask); |
| free_cpumask_var(rd->online); |
| free_cpumask_var(rd->span); |
| kfree(rd); |
| } |
| |
| void rq_attach_root(struct rq *rq, struct root_domain *rd) |
| { |
| struct root_domain *old_rd = NULL; |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&rq->lock, flags); |
| |
| if (rq->rd) { |
| old_rd = rq->rd; |
| |
| if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
| set_rq_offline(rq); |
| |
| cpumask_clear_cpu(rq->cpu, old_rd->span); |
| |
| /* |
| * If we dont want to free the old_rd yet then |
| * set old_rd to NULL to skip the freeing later |
| * in this function: |
| */ |
| if (!atomic_dec_and_test(&old_rd->refcount)) |
| old_rd = NULL; |
| } |
| |
| atomic_inc(&rd->refcount); |
| rq->rd = rd; |
| |
| cpumask_set_cpu(rq->cpu, rd->span); |
| if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
| set_rq_online(rq); |
| |
| raw_spin_unlock_irqrestore(&rq->lock, flags); |
| |
| if (old_rd) |
| call_rcu_sched(&old_rd->rcu, free_rootdomain); |
| } |
| |
| static int init_rootdomain(struct root_domain *rd) |
| { |
| memset(rd, 0, sizeof(*rd)); |
| |
| if (!zalloc_cpumask_var(&rd->span, GFP_KERNEL)) |
| goto out; |
| if (!zalloc_cpumask_var(&rd->online, GFP_KERNEL)) |
| goto free_span; |
| if (!zalloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) |
| goto free_online; |
| if (!zalloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
| goto free_dlo_mask; |
| |
| init_dl_bw(&rd->dl_bw); |
| if (cpudl_init(&rd->cpudl) != 0) |
| goto free_rto_mask; |
| |
| if (cpupri_init(&rd->cpupri) != 0) |
| goto free_cpudl; |
| return 0; |
| |
| free_cpudl: |
| cpudl_cleanup(&rd->cpudl); |
| free_rto_mask: |
| free_cpumask_var(rd->rto_mask); |
| free_dlo_mask: |
| free_cpumask_var(rd->dlo_mask); |
| free_online: |
| free_cpumask_var(rd->online); |
| free_span: |
| free_cpumask_var(rd->span); |
| out: |
| return -ENOMEM; |
| } |
| |
| /* |
| * By default the system creates a single root-domain with all CPUs as |
| * members (mimicking the global state we have today). |
| */ |
| struct root_domain def_root_domain; |
| |
| void init_defrootdomain(void) |
| { |
| init_rootdomain(&def_root_domain); |
| |
| atomic_set(&def_root_domain.refcount, 1); |
| } |
| |
| static struct root_domain *alloc_rootdomain(void) |
| { |
| struct root_domain *rd; |
| |
| rd = kmalloc(sizeof(*rd), GFP_KERNEL); |
| if (!rd) |
| return NULL; |
| |
| if (init_rootdomain(rd) != 0) { |
| kfree(rd); |
| return NULL; |
| } |
| |
| return rd; |
| } |
| |
| static void free_sched_groups(struct sched_group *sg, int free_sgc) |
| { |
| struct sched_group *tmp, *first; |
| |
| if (!sg) |
| return; |
| |
| first = sg; |
| do { |
| tmp = sg->next; |
| |
| if (free_sgc && atomic_dec_and_test(&sg->sgc->ref)) |
| kfree(sg->sgc); |
| |
| kfree(sg); |
| sg = tmp; |
| } while (sg != first); |
| } |
| |
| static void destroy_sched_domain(struct sched_domain *sd) |
| { |
| /* |
| * 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->sgc); |
| kfree(sd->groups); |
| } |
| if (sd->shared && atomic_dec_and_test(&sd->shared->ref)) |
| kfree(sd->shared); |
| kfree(sd); |
| } |
| |
| static void destroy_sched_domains_rcu(struct rcu_head *rcu) |
| { |
| struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); |
| |
| while (sd) { |
| struct sched_domain *parent = sd->parent; |
| destroy_sched_domain(sd); |
| sd = parent; |
| } |
| } |
| |
| static void destroy_sched_domains(struct sched_domain *sd) |
| { |
| if (sd) |
| call_rcu(&sd->rcu, destroy_sched_domains_rcu); |
| } |
| |
| /* |
| * Keep a special pointer to the highest sched_domain that has |
| * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this |
| * allows us to avoid some pointer chasing select_idle_sibling(). |
| * |
| * Also keep a unique ID per domain (we use the first CPU number in |
| * the cpumask of the domain), this allows us to quickly tell if |
| * two CPUs are in the same cache domain, see cpus_share_cache(). |
| */ |
| DEFINE_PER_CPU(struct sched_domain *, sd_llc); |
| DEFINE_PER_CPU(int, sd_llc_size); |
| DEFINE_PER_CPU(int, sd_llc_id); |
| DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); |
| DEFINE_PER_CPU(struct sched_domain *, sd_numa); |
| DEFINE_PER_CPU(struct sched_domain *, sd_asym); |
| |
| static void update_top_cache_domain(int cpu) |
| { |
| struct sched_domain_shared *sds = NULL; |
| struct sched_domain *sd; |
| int id = cpu; |
| int size = 1; |
| |
| sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); |
| if (sd) { |
| id = cpumask_first(sched_domain_span(sd)); |
| size = cpumask_weight(sched_domain_span(sd)); |
| sds = sd->shared; |
| } |
| |
| rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); |
| per_cpu(sd_llc_size, cpu) = size; |
| per_cpu(sd_llc_id, cpu) = id; |
| rcu_assign_pointer(per_cpu(sd_llc_shared, cpu), sds); |
| |
| sd = lowest_flag_domain(cpu, SD_NUMA); |
| rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); |
| |
| sd = highest_flag_domain(cpu, SD_ASYM_PACKING); |
| rcu_assign_pointer(per_cpu(sd_asym, cpu), sd); |
| } |
| |
| /* |
| * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
| * hold the hotplug lock. |
| */ |
| static void |
| cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) |
| { |
| struct rq *rq = cpu_rq(cpu); |
| struct sched_domain *tmp; |
| |
| /* Remove the sched domains which do not contribute to scheduling. */ |
| for (tmp = sd; tmp; ) { |
| struct sched_domain *parent = tmp->parent; |
| if (!parent) |
| break; |
| |
| if (sd_parent_degenerate(tmp, parent)) { |
| tmp->parent = parent->parent; |
| if (parent->parent) |
| parent->parent->child = tmp; |
| /* |
| * Transfer SD_PREFER_SIBLING down in case of a |
| * degenerate parent; the spans match for this |
| * so the property transfers. |
| */ |
| if (parent->flags & SD_PREFER_SIBLING) |
| tmp->flags |= SD_PREFER_SIBLING; |
| destroy_sched_domain(parent); |
| } else |
| tmp = tmp->parent; |
| } |
| |
| if (sd && sd_degenerate(sd)) { |
| tmp = sd; |
| sd = sd->parent; |
| destroy_sched_domain(tmp); |
| if (sd) |
| sd->child = NULL; |
| } |
| |
| sched_domain_debug(sd, cpu); |
| |
| rq_attach_root(rq, rd); |
| tmp = rq->sd; |
| rcu_assign_pointer(rq->sd, sd); |
| destroy_sched_domains(tmp); |
| |
| update_top_cache_domain(cpu); |
| } |
| |
| /* Setup the mask of CPUs configured for isolated domains */ |
| static int __init isolated_cpu_setup(char *str) |
| { |
| int ret; |
| |
| alloc_bootmem_cpumask_var(&cpu_isolated_map); |
| ret = cpulist_parse(str, cpu_isolated_map); |
| if (ret) { |
| pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids); |
| return 0; |
| } |
| return 1; |
| } |
| __setup("isolcpus=", isolated_cpu_setup); |
| |
| struct s_data { |
| struct sched_domain ** __percpu sd; |
| struct root_domain *rd; |
| }; |
| |
| enum s_alloc { |
| sa_rootdomain, |
| sa_sd, |
| sa_sd_storage, |
| sa_none, |
| }; |
| |
| /* |
| * Build an iteration mask that can exclude certain CPUs from the upwards |
| * domain traversal. |
| * |
| * Only CPUs that can arrive at this group should be considered to continue |
| * balancing. |
| */ |
| static void |
| build_group_mask(struct sched_domain *sd, struct sched_group *sg, struct cpumask *mask) |
| { |
| const struct cpumask *sg_span = sched_group_cpus(sg); |
| struct sd_data *sdd = sd->private; |
| struct sched_domain *sibling; |
| int i; |
| |
| cpumask_clear(mask); |
| |
| for_each_cpu(i, sg_span) { |
| sibling = *per_cpu_ptr(sdd->sd, i); |
| |
| /* |
| * Can happen in the asymmetric case, where these siblings are |
| * unused. The mask will not be empty because those CPUs that |
| * do have the top domain _should_ span the domain. |
| */ |
| if (!sibling->child) |
| continue; |
| |
| /* If we would not end up here, we can't continue from here */ |
| if (!cpumask_equal(sg_span, sched_domain_span(sibling->child))) |
| continue; |
| |
| cpumask_set_cpu(i, mask); |
| } |
| |
| /* We must not have empty masks here */ |
| WARN_ON_ONCE(cpumask_empty(mask)); |
| } |
| |
| /* |
| * Return the canonical balance CPU for this group, this is the first CPU |
| * of this group that's also in the iteration mask. |
| */ |
| int group_balance_cpu(struct sched_group *sg) |
| { |
| return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg)); |
| } |
| |
| static struct sched_group * |
| build_group_from_child_sched_domain(struct sched_domain *sd, int cpu) |
| { |
| struct sched_group *sg; |
| struct cpumask *sg_span; |
| |
| sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), |
| GFP_KERNEL, cpu_to_node(cpu)); |
| |
| if (!sg) |
| return NULL; |
| |
| sg_span = sched_group_cpus(sg); |
| if (sd->child) |
| cpumask_copy(sg_span, sched_domain_span(sd->child)); |
| else |
| cpumask_copy(sg_span, sched_domain_span(sd)); |
| |
| return sg; |
| } |
| |
| static void init_overlap_sched_group(struct sched_domain *sd, |
| struct sched_group *sg) |
| { |
| struct cpumask *mask = sched_domains_tmpmask2; |
| struct sd_data *sdd = sd->private; |
| struct cpumask *sg_span; |
| int cpu; |
| |
| build_group_mask(sd, sg, mask); |
| cpu = cpumask_first_and(sched_group_cpus(sg), mask); |
| |
| sg->sgc = *per_cpu_ptr(sdd->sgc, cpu); |
| if (atomic_inc_return(&sg->sgc->ref) == 1) |
| cpumask_copy(sched_group_mask(sg), mask); |
| |
| /* |
| * Initialize sgc->capacity such that even if we mess up the |
| * domains and no possible iteration will get us here, we won't |
| * die on a /0 trap. |
| */ |
| sg_span = sched_group_cpus(sg); |
| sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); |
| sg->sgc->min_capacity = SCHED_CAPACITY_SCALE; |
| } |
| |
| static int |
| build_overlap_sched_groups(struct sched_domain *sd, int cpu) |
| { |
| struct sched_group *first = NULL, *last = 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 *sibling; |
| int i; |
| |
| cpumask_clear(covered); |
| |
| for_each_cpu_wrap(i, span, cpu) { |
| struct cpumask *sg_span; |
| |
| if (cpumask_test_cpu(i, covered)) |
| continue; |
| |
| sibling = *per_cpu_ptr(sdd->sd, i); |
| |
| /* |
| * Asymmetric node setups can result in situations where the |
| * domain tree is of unequal depth, make sure to skip domains |
| * that already cover the entire range. |
| * |
| * In that case build_sched_domains() will have terminated the |
| * iteration early and our sibling sd spans will be empty. |
| * Domains should always include the CPU they're built on, so |
| * check that. |
| */ |
| if (!cpumask_test_cpu(i, sched_domain_span(sibling))) |
| continue; |
| |
| sg = build_group_from_child_sched_domain(sibling, cpu); |
| if (!sg) |
| goto fail; |
| |
| sg_span = sched_group_cpus(sg); |
| cpumask_or(covered, covered, sg_span); |
| |
| init_overlap_sched_group(sd, sg); |
| |
| if (!first) |
| first = sg; |
| if (last) |
| last->next = sg; |
| last = sg; |
| last->next = first; |
| } |
| sd->groups = first; |
| |
| 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); |
| struct sched_domain *child = sd->child; |
| |
| if (child) |
| cpu = cpumask_first(sched_domain_span(child)); |
| |
| if (sg) { |
| *sg = *per_cpu_ptr(sdd->sg, cpu); |
| (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu); |
| |
| /* For claim_allocations: */ |
| atomic_set(&(*sg)->sgc->ref, 1); |
| } |
| |
| return cpu; |
| } |
| |
| /* |
| * 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_capacity to 0. |
| * |
| * Assumes the sched_domain tree is fully constructed |
| */ |
| static int |
| build_sched_groups(struct sched_domain *sd, int cpu) |
| { |
| struct sched_group *first = NULL, *last = NULL; |
| struct sd_data *sdd = sd->private; |
| const struct cpumask *span = sched_domain_span(sd); |
| struct cpumask *covered; |
| int i; |
| |
| get_group(cpu, sdd, &sd->groups); |
| atomic_inc(&sd->groups->ref); |
| |
| if (cpu != cpumask_first(span)) |
| return 0; |
| |
| lockdep_assert_held(&sched_domains_mutex); |
| covered = sched_domains_tmpmask; |
| |
| cpumask_clear(covered); |
| |
| for_each_cpu(i, span) { |
| struct sched_group *sg; |
| int group, j; |
| |
| if (cpumask_test_cpu(i, covered)) |
| continue; |
| |
| group = get_group(i, sdd, &sg); |
| cpumask_setall(sched_group_mask(sg)); |
| |
| for_each_cpu(j, span) { |
| if (get_group(j, sdd, NULL) != group) |
| continue; |
| |
| cpumask_set_cpu(j, covered); |
| cpumask_set_cpu(j, sched_group_cpus(sg)); |
| } |
| |
| if (!first) |
| first = sg; |
| if (last) |
| last->next = sg; |
| last = sg; |
| } |
| last->next = first; |
| |
| return 0; |
| } |
| |
| /* |
| * Initialize sched groups cpu_capacity. |
| * |
| * cpu_capacity indicates the capacity of sched group, which is used while |
| * distributing the load between different sched groups in a sched domain. |
| * Typically cpu_capacity for all the groups in a sched domain will be same |
| * unless there are asymmetries in the topology. If there are asymmetries, |
| * group having more cpu_capacity will pickup more load compared to the |
| * group having less cpu_capacity. |
| */ |
| static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) |
| { |
| struct sched_group *sg = sd->groups; |
| |
| WARN_ON(!sg); |
| |
| do { |
| int cpu, max_cpu = -1; |
| |
| sg->group_weight = cpumask_weight(sched_group_cpus(sg)); |
| |
| if (!(sd->flags & SD_ASYM_PACKING)) |
| goto next; |
| |
| for_each_cpu(cpu, sched_group_cpus(sg)) { |
| if (max_cpu < 0) |
| max_cpu = cpu; |
| else if (sched_asym_prefer(cpu, max_cpu)) |
| max_cpu = cpu; |
| } |
| sg->asym_prefer_cpu = max_cpu; |
| |
| next: |
| sg = sg->next; |
| } while (sg != sd->groups); |
| |
| if (cpu != group_balance_cpu(sg)) |
| return; |
| |
| update_group_capacity(sd, cpu); |
| } |
| |
| /* |
| * Initializers for schedule domains |
| * Non-inlined to reduce accumulated stack pressure in build_sched_domains() |
| */ |
| |
| static int default_relax_domain_level = -1; |
| int sched_domain_level_max; |
| |
| static int __init setup_relax_domain_level(char *str) |
| { |
| if (kstrtoint(str, 0, &default_relax_domain_level)) |
| pr_warn("Unable to set relax_domain_level\n"); |
| |
| return 1; |
| } |
| __setup("relax_domain_level=", setup_relax_domain_level); |
| |
| static void set_domain_attribute(struct sched_domain *sd, |
| struct sched_domain_attr *attr) |
| { |
| int request; |
| |
| if (!attr || attr->relax_domain_level < 0) { |
| if (default_relax_domain_level < 0) |
| return; |
| else |
| request = default_relax_domain_level; |
| } else |
| request = attr->relax_domain_level; |
| if (request < sd->level) { |
| /* Turn off idle balance on this domain: */ |
| sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
| } else { |
| /* Turn on idle balance on this domain: */ |
| sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
| } |
| } |
| |
| static void __sdt_free(const struct cpumask *cpu_map); |
| static int __sdt_alloc(const struct cpumask *cpu_map); |
| |
| static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
| const struct cpumask *cpu_map) |
| { |
| switch (what) { |
| case sa_rootdomain: |
| if (!atomic_read(&d->rd->refcount)) |
| free_rootdomain(&d->rd->rcu); |
| /* Fall through */ |
| case sa_sd: |
| free_percpu(d->sd); |
| /* Fall through */ |
| case sa_sd_storage: |
| __sdt_free(cpu_map); |
| /* Fall through */ |
| case sa_none: |
| break; |
| } |
| } |
| |
| static enum s_alloc |
| __visit_domain_allocation_hell(struct s_data *d, const struct cpumask *cpu_map) |
| { |
| memset(d, 0, sizeof(*d)); |
| |
| if (__sdt_alloc(cpu_map)) |
| return sa_sd_storage; |
| d->sd = alloc_percpu(struct sched_domain *); |
| if (!d->sd) |
| return sa_sd_storage; |
| d->rd = alloc_rootdomain(); |
| if (!d->rd) |
| return sa_sd; |
| return sa_rootdomain; |
| } |
| |
| /* |
| * NULL the sd_data elements we've used to build the sched_domain and |
| * sched_group structure so that the subsequent __free_domain_allocs() |
| * will not free the data we're using. |
| */ |
| static void claim_allocations(int cpu, struct sched_domain *sd) |
| { |
| struct sd_data *sdd = sd->private; |
| |
| WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); |
| *per_cpu_ptr(sdd->sd, cpu) = NULL; |
| |
| if (atomic_read(&(*per_cpu_ptr(sdd->sds, cpu))->ref)) |
| *per_cpu_ptr(sdd->sds, cpu) = NULL; |
| |
| if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
| *per_cpu_ptr(sdd->sg, cpu) = NULL; |
| |
| if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref)) |
| *per_cpu_ptr(sdd->sgc, cpu) = NULL; |
| } |
| |
| #ifdef CONFIG_NUMA |
| static int sched_domains_numa_levels; |
| enum numa_topology_type sched_numa_topology_type; |
| static int *sched_domains_numa_distance; |
| int sched_max_numa_distance; |
| static struct cpumask ***sched_domains_numa_masks; |
| static int sched_domains_curr_level; |
| #endif |
| |
| /* |
| * SD_flags allowed in topology descriptions. |
| * |
| * These flags are purely descriptive of the topology and do not prescribe |
| * behaviour. Behaviour is artificial and mapped in the below sd_init() |
| * function: |
| * |
| * SD_SHARE_CPUCAPACITY - describes SMT topologies |
| * SD_SHARE_PKG_RESOURCES - describes shared caches |
| * SD_NUMA - describes NUMA topologies |
| * SD_SHARE_POWERDOMAIN - describes shared power domain |
| * SD_ASYM_CPUCAPACITY - describes mixed capacity topologies |
| * |
| * Odd one out, which beside describing the topology has a quirk also |
| * prescribes the desired behaviour that goes along with it: |
| * |
| * SD_ASYM_PACKING - describes SMT quirks |
| */ |
| #define TOPOLOGY_SD_FLAGS \ |
| (SD_SHARE_CPUCAPACITY | \ |
| SD_SHARE_PKG_RESOURCES | \ |
| SD_NUMA | \ |
| SD_ASYM_PACKING | \ |
| SD_ASYM_CPUCAPACITY | \ |
| SD_SHARE_POWERDOMAIN) |
| |
| static struct sched_domain * |
| sd_init(struct sched_domain_topology_level *tl, |
| const struct cpumask *cpu_map, |
| struct sched_domain *child, int cpu) |
| { |
| struct sd_data *sdd = &tl->data; |
| struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
| int sd_id, sd_weight, sd_flags = 0; |
| |
| #ifdef CONFIG_NUMA |
| /* |
| * Ugly hack to pass state to sd_numa_mask()... |
| */ |
| sched_domains_curr_level = tl->numa_level; |
| #endif |
| |
| sd_weight = cpumask_weight(tl->mask(cpu)); |
| |
| if (tl->sd_flags) |
| sd_flags = (*tl->sd_flags)(); |
| if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS, |
| "wrong sd_flags in topology description\n")) |
| sd_flags &= ~TOPOLOGY_SD_FLAGS; |
| |
| *sd = (struct sched_domain){ |
| .min_interval = sd_weight, |
| .max_interval = 2*sd_weight, |
| .busy_factor = 32, |
| .imbalance_pct = 125, |
| |
| .cache_nice_tries = 0, |
| .busy_idx = 0, |
| .idle_idx = 0, |
| .newidle_idx = 0, |
| .wake_idx = 0, |
| .forkexec_idx = 0, |
| |
| .flags = 1*SD_LOAD_BALANCE |
| | 1*SD_BALANCE_NEWIDLE |
| | 1*SD_BALANCE_EXEC |
| | 1*SD_BALANCE_FORK |
| | 0*SD_BALANCE_WAKE |
| | 1*SD_WAKE_AFFINE |
| | 0*SD_SHARE_CPUCAPACITY |
| | 0*SD_SHARE_PKG_RESOURCES |
| | 0*SD_SERIALIZE |
| | 0*SD_PREFER_SIBLING |
| | 0*SD_NUMA |
| | sd_flags |
| , |
| |
| .last_balance = jiffies, |
| .balance_interval = sd_weight, |
| .smt_gain = 0, |
| .max_newidle_lb_cost = 0, |
| .next_decay_max_lb_cost = jiffies, |
| .child = child, |
| #ifdef CONFIG_SCHED_DEBUG |
| .name = tl->name, |
| #endif |
| }; |
| |
| cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); |
| sd_id = cpumask_first(sched_domain_span(sd)); |
| |
| /* |
| * Convert topological properties into behaviour. |
| */ |
| |
| if (sd->flags & SD_ASYM_CPUCAPACITY) { |
| struct sched_domain *t = sd; |
| |
| for_each_lower_domain(t) |
| t->flags |= SD_BALANCE_WAKE; |
| } |
| |
| if (sd->flags & SD_SHARE_CPUCAPACITY) { |
| sd->flags |= SD_PREFER_SIBLING; |
| sd->imbalance_pct = 110; |
| sd->smt_gain = 1178; /* ~15% */ |
| |
| } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { |
| sd->imbalance_pct = 117; |
| sd->cache_nice_tries = 1; |
| sd->busy_idx = 2; |
| |
| #ifdef CONFIG_NUMA |
| } else if (sd->flags & SD_NUMA) { |
| sd->cache_nice_tries = 2; |
| sd->busy_idx = 3; |
| sd->idle_idx = 2; |
| |
| sd->flags |= SD_SERIALIZE; |
| if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) { |
| sd->flags &= ~(SD_BALANCE_EXEC | |
| SD_BALANCE_FORK | |
| SD_WAKE_AFFINE); |
| } |
| |
| #endif |
| } else { |
| sd->flags |= SD_PREFER_SIBLING; |
| sd->cache_nice_tries = 1; |
| sd->busy_idx = 2; |
| sd->idle_idx = 1; |
| } |
| |
| /* |
| * For all levels sharing cache; connect a sched_domain_shared |
| * instance. |
| */ |
| if (sd->flags & SD_SHARE_PKG_RESOURCES) { |
| sd->shared = *per_cpu_ptr(sdd->sds, sd_id); |
| atomic_inc(&sd->shared->ref); |
| atomic_set(&sd->shared->nr_busy_cpus, sd_weight); |
| } |
| |
| sd->private = sdd; |
| |
| return sd; |
| } |
| |
| /* |
| * Topology list, bottom-up. |
| */ |
| static struct sched_domain_topology_level default_topology[] = { |
| #ifdef CONFIG_SCHED_SMT |
| { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, |
| #endif |
| #ifdef CONFIG_SCHED_MC |
| { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, |
| #endif |
| { cpu_cpu_mask, SD_INIT_NAME(DIE) }, |
| { NULL, }, |
| }; |
| |
| static struct sched_domain_topology_level *sched_domain_topology = |
| default_topology; |
| |
| #define for_each_sd_topology(tl) \ |
| for (tl = sched_domain_topology; tl->mask; tl++) |
| |
| void set_sched_topology(struct sched_domain_topology_level *tl) |
| { |
| if (WARN_ON_ONCE(sched_smp_initialized)) |
| return; |
| |
| sched_domain_topology = tl; |
| } |
| |
| #ifdef CONFIG_NUMA |
| |
| static const struct cpumask *sd_numa_mask(int cpu) |
| { |
| return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; |
| } |
| |
| static void sched_numa_warn(const char *str) |
| { |
| static int done = false; |
| int i,j; |
| |
| if (done) |
| return; |
| |
| done = true; |
| |
| printk(KERN_WARNING "ERROR: %s\n\n", str); |
| |
| for (i = 0; i < nr_node_ids; i++) { |
| printk(KERN_WARNING " "); |
| for (j = 0; j < nr_node_ids; j++) |
| printk(KERN_CONT "%02d ", node_distance(i,j)); |
| printk(KERN_CONT "\n"); |
| } |
| printk(KERN_WARNING "\n"); |
| } |
| |
| bool find_numa_distance(int distance) |
| { |
| int i; |
| |
| if (distance == node_distance(0, 0)) |
| return true; |
| |
| for (i = 0; i < sched_domains_numa_levels; i++) { |
| if (sched_domains_numa_distance[i] == distance) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* |
| * A system can have three types of NUMA topology: |
| * NUMA_DIRECT: all nodes are directly connected, or not a NUMA system |
| * NUMA_GLUELESS_MESH: some nodes reachable through intermediary nodes |
| * NUMA_BACKPLANE: nodes can reach other nodes through a backplane |
| * |
| * The difference between a glueless mesh topology and a backplane |
| * topology lies in whether communication between not directly |
| * connected nodes goes through intermediary nodes (where programs |
| * could run), or through backplane controllers. This affects |
| * placement of programs. |
| * |
| * The type of topology can be discerned with the following tests: |
| * - If the maximum distance between any nodes is 1 hop, the system |
| * is directly connected. |
| * - If for two nodes A and B, located N > 1 hops away from each other, |
| * there is an intermediary node C, which is < N hops away from both |
| * nodes A and B, the system is a glueless mesh. |
| */ |
| static void init_numa_topology_type(void) |
| { |
| int a, b, c, n; |
| |
| n = sched_max_numa_distance; |
| |
| if (sched_domains_numa_levels <= 1) { |
| sched_numa_topology_type = NUMA_DIRECT; |
| return; |
| } |
| |
| for_each_online_node(a) { |
| for_each_online_node(b) { |
| /* Find two nodes furthest removed from each other. */ |
| if (node_distance(a, b) < n) |
| continue; |
| |
| /* Is there an intermediary node between a and b? */ |
| for_each_online_node(c) { |
| if (node_distance(a, c) < n && |
| node_distance(b, c) < n) { |
| sched_numa_topology_type = |
| NUMA_GLUELESS_MESH; |
| return; |
| } |
| } |
| |
| sched_numa_topology_type = NUMA_BACKPLANE; |
| return; |
| } |
| } |
| } |
| |
| void sched_init_numa(void) |
| { |
| int next_distance, curr_distance = node_distance(0, 0); |
| struct sched_domain_topology_level *tl; |
| int level = 0; |
| int i, j, k; |
| |
| sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL); |
| if (!sched_domains_numa_distance) |
| return; |
| |
| /* |
| * O(nr_nodes^2) deduplicating selection sort -- in order to find the |
| * unique distances in the node_distance() table. |
| * |
| * Assumes node_distance(0,j) includes all distances in |
| * node_distance(i,j) in order to avoid cubic time. |
| */ |
| next_distance = curr_distance; |
| for (i = 0; i < nr_node_ids; i++) { |
| for (j = 0; j < nr_node_ids; j++) { |
| for (k = 0; k < nr_node_ids; k++) { |
| int distance = node_distance(i, k); |
| |
| if (distance > curr_distance && |
| (distance < next_distance || |
| next_distance == curr_distance)) |
| next_distance = distance; |
| |
| /* |
| * While not a strong assumption it would be nice to know |
| * about cases where if node A is connected to B, B is not |
| * equally connected to A. |
| */ |
| if (sched_debug() && node_distance(k, i) != distance) |
| sched_numa_warn("Node-distance not symmetric"); |
| |
| if (sched_debug() && i && !find_numa_distance(distance)) |
| sched_numa_warn("Node-0 not representative"); |
| } |
| if (next_distance != curr_distance) { |
| sched_domains_numa_distance[level++] = next_distance; |
| sched_domains_numa_levels = level; |
| curr_distance = next_distance; |
| } else break; |
| } |
| |
| /* |
| * In case of sched_debug() we verify the above assumption. |
| */ |
| if (!sched_debug()) |
| break; |
| } |
| |
| if (!level) |
| return; |
| |
| /* |
| * 'level' contains the number of unique distances, excluding the |
| * identity distance node_distance(i,i). |
| * |
| * The sched_domains_numa_distance[] array includes the actual distance |
| * numbers. |
| */ |
| |
| /* |
| * Here, we should temporarily reset sched_domains_numa_levels to 0. |
| * If it fails to allocate memory for array sched_domains_numa_masks[][], |
| * the array will contain less then 'level' members. This could be |
| * dangerous when we use it to iterate array sched_domains_numa_masks[][] |
| * in other functions. |
| * |
| * We reset it to 'level' at the end of this function. |
| */ |
| sched_domains_numa_levels = 0; |
| |
| sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); |
| if (!sched_domains_numa_masks) |
| return; |
| |
| /* |
| * Now for each level, construct a mask per node which contains all |
| * CPUs of nodes that are that many hops away from us. |
| */ |
| for (i = 0; i < level; i++) { |
| sched_domains_numa_masks[i] = |
| kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); |
| if (!sched_domains_numa_masks[i]) |
| return; |
| |
| for (j = 0; j < nr_node_ids; j++) { |
| struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); |
| if (!mask) |
| return; |
| |
| sched_domains_numa_masks[i][j] = mask; |
| |
| for_each_node(k) { |
| if (node_distance(j, k) > sched_domains_numa_distance[i]) |
| continue; |
| |
| cpumask_or(mask, mask, cpumask_of_node(k)); |
| } |
| } |
| } |
| |
| /* Compute default topology size */ |
| for (i = 0; sched_domain_topology[i].mask; i++); |
| |
| tl = kzalloc((i + level + 1) * |
| sizeof(struct sched_domain_topology_level), GFP_KERNEL); |
| if (!tl) |
| return; |
| |
| /* |
| * Copy the default topology bits.. |
| */ |
| for (i = 0; sched_domain_topology[i].mask; i++) |
| tl[i] = sched_domain_topology[i]; |
| |
| /* |
| * .. and append 'j' levels of NUMA goodness. |
| */ |
| for (j = 0; j < level; i++, j++) { |
| tl[i] = (struct sched_domain_topology_level){ |
| .mask = sd_numa_mask, |
| .sd_flags = cpu_numa_flags, |
| .flags = SDTL_OVERLAP, |
| .numa_level = j, |
| SD_INIT_NAME(NUMA) |
| }; |
| } |
| |
| sched_domain_topology = tl; |
| |
| sched_domains_numa_levels = level; |
| sched_max_numa_distance = sched_domains_numa_distance[level - 1]; |
| |
| init_numa_topology_type(); |
| } |
| |
| void sched_domains_numa_masks_set(unsigned int cpu) |
| { |
| int node = cpu_to_node(cpu); |
| int i, j; |
| |
| for (i = 0; i < sched_domains_numa_levels; i++) { |
| for (j = 0; j < nr_node_ids; j++) { |
| if (node_distance(j, node) <= sched_domains_numa_distance[i]) |
| cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); |
| } |
| } |
| } |
| |
| void sched_domains_numa_masks_clear(unsigned int cpu) |
| { |
| int i, j; |
| |
| for (i = 0; i < sched_domains_numa_levels; i++) { |
| for (j = 0; j < nr_node_ids; j++) |
| cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]); |
| } |
| } |
| |
| #endif /* CONFIG_NUMA */ |
| |
| static int __sdt_alloc(const struct cpumask *cpu_map) |
| { |
| struct sched_domain_topology_level *tl; |
| int j; |
| |
| for_each_sd_topology(tl) { |
| struct sd_data *sdd = &tl->data; |
| |
| sdd->sd = alloc_percpu(struct sched_domain *); |
| if (!sdd->sd) |
| return -ENOMEM; |
| |
| sdd->sds = alloc_percpu(struct sched_domain_shared *); |
| if (!sdd->sds) |
| return -ENOMEM; |
| |
| sdd->sg = alloc_percpu(struct sched_group *); |
| if (!sdd->sg) |
| return -ENOMEM; |
| |
| sdd->sgc = alloc_percpu(struct sched_group_capacity *); |
| if (!sdd->sgc) |
| return -ENOMEM; |
| |
| for_each_cpu(j, cpu_map) { |
| struct sched_domain *sd; |
| struct sched_domain_shared *sds; |
| struct sched_group *sg; |
| struct sched_group_capacity *sgc; |
| |
| sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), |
| GFP_KERNEL, cpu_to_node(j)); |
| if (!sd) |
| return -ENOMEM; |
| |
| *per_cpu_ptr(sdd->sd, j) = sd; |
| |
| sds = kzalloc_node(sizeof(struct sched_domain_shared), |
| GFP_KERNEL, cpu_to_node(j)); |
| if (!sds) |
| return -ENOMEM; |
| |
| *per_cpu_ptr(sdd->sds, j) = sds; |
| |
| sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), |
| GFP_KERNEL, cpu_to_node(j)); |
| if (!sg) |
| return -ENOMEM; |
| |
| sg->next = sg; |
| |
| *per_cpu_ptr(sdd->sg, j) = sg; |
| |
| sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(), |
| GFP_KERNEL, cpu_to_node(j)); |
| if (!sgc) |
| return -ENOMEM; |
| |
| #ifdef CONFIG_SCHED_DEBUG |
| sgc->id = j; |
| #endif |
| |
| *per_cpu_ptr(sdd->sgc, j) = sgc; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void __sdt_free(const struct cpumask *cpu_map) |
| { |
| struct sched_domain_topology_level *tl; |
| int j; |
| |
| for_each_sd_topology(tl) { |
| struct sd_data *sdd = &tl->data; |
| |
| for_each_cpu(j, cpu_map) { |
| struct sched_domain *sd; |
| |
| if (sdd->sd) { |
| sd = *per_cpu_ptr(sdd->sd, j); |
| if (sd && (sd->flags & SD_OVERLAP)) |
| free_sched_groups(sd->groups, 0); |
| kfree(*per_cpu_ptr(sdd->sd, j)); |
| } |
| |
| if (sdd->sds) |
| kfree(*per_cpu_ptr(sdd->sds, j)); |
| if (sdd->sg) |
| kfree(*per_cpu_ptr(sdd->sg, j)); |
| if (sdd->sgc) |
| kfree(*per_cpu_ptr(sdd->sgc, j)); |
| } |
| free_percpu(sdd->sd); |
| sdd->sd = NULL; |
| free_percpu(sdd->sds); |
| sdd->sds = NULL; |
| free_percpu(sdd->sg); |
| sdd->sg = NULL; |
| free_percpu(sdd->sgc); |
| sdd->sgc = NULL; |
| } |
| } |
| |
| struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
| const struct cpumask *cpu_map, struct sched_domain_attr *attr, |
| struct sched_domain *child, int cpu) |
| { |
| struct sched_domain *sd = sd_init(tl, cpu_map, child, cpu); |
| |
| if (child) { |
| sd->level = child->level + 1; |
| sched_domain_level_max = max(sched_domain_level_max, sd->level); |
| child->parent = sd; |
| |
| if (!cpumask_subset(sched_domain_span(child), |
| sched_domain_span(sd))) { |
| pr_err("BUG: arch topology borken\n"); |
| #ifdef CONFIG_SCHED_DEBUG |
| pr_err(" the %s domain not a subset of the %s domain\n", |
| child->name, sd->name); |
| #endif |
| /* Fixup, ensure @sd has at least @child cpus. */ |
| cpumask_or(sched_domain_span(sd), |
| sched_domain_span(sd), |
| sched_domain_span(child)); |
| } |
| |
| } |
| set_domain_attribute(sd, attr); |
| |
| return sd; |
| } |
| |
| /* |
| * Build sched domains for a given set of CPUs and attach the sched domains |
| * to the individual CPUs |
| */ |
| static int |
| build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *attr) |
| { |
| enum s_alloc alloc_state; |
| struct sched_domain *sd; |
| struct s_data d; |
| struct rq *rq = NULL; |
| int i, ret = -ENOMEM; |
| |
| alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
| if (alloc_state != sa_rootdomain) |
| goto error; |
| |
| /* Set up domains for CPUs specified by the cpu_map: */ |
| for_each_cpu(i, cpu_map) { |
| struct sched_domain_topology_level *tl; |
| |
| sd = NULL; |
| for_each_sd_topology(tl) { |
| sd = build_sched_domain(tl, cpu_map, attr, sd, i); |
| if (tl == sched_domain_topology) |
| *per_cpu_ptr(d.sd, i) = sd; |
| if (tl->flags & SDTL_OVERLAP) |
| sd->flags |= SD_OVERLAP; |
| if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
| break; |
| } |
| } |
| |
| /* Build the groups for the domains */ |
| 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)); |
| if (sd->flags & SD_OVERLAP) { |
| if (build_overlap_sched_groups(sd, i)) |
| goto error; |
| } else { |
| if (build_sched_groups(sd, i)) |
| goto error; |
| } |
| } |
| } |
| |
| /* Calculate CPU capacity for physical packages and nodes */ |
| for (i = nr_cpumask_bits-1; i >= 0; i--) { |
| if (!cpumask_test_cpu(i, cpu_map)) |
| continue; |
| |
| for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
| claim_allocations(i, sd); |
| init_sched_groups_capacity(i, sd); |
| } |
| } |
| |
| /* Attach the domains */ |
| rcu_read_lock(); |
| for_each_cpu(i, cpu_map) { |
| rq = cpu_rq(i); |
| sd = *per_cpu_ptr(d.sd, i); |
| |
| /* Use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing: */ |
| if (rq->cpu_capacity_orig > READ_ONCE(d.rd->max_cpu_capacity)) |
| WRITE_ONCE(d.rd->max_cpu_capacity, rq->cpu_capacity_orig); |
| |
| cpu_attach_domain(sd, d.rd, i); |
| } |
| rcu_read_unlock(); |
| |
| if (rq && sched_debug_enabled) { |
| pr_info("span: %*pbl (max cpu_capacity = %lu)\n", |
| cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity); |
| } |
| |
| ret = 0; |
| error: |
| __free_domain_allocs(&d, alloc_state, cpu_map); |
| return ret; |
| } |
| |
| /* Current sched domains: */ |
| static cpumask_var_t *doms_cur; |
| |
| /* Number of sched domains in 'doms_cur': */ |
| static int ndoms_cur; |
| |
| /* Attribues of custom domains in 'doms_cur' */ |
| static struct sched_domain_attr *dattr_cur; |
| |
| /* |
| * Special case: If a kmalloc() of a doms_cur partition (array of |
| * cpumask) fails, then fallback to a single sched domain, |
| * as determined by the single cpumask fallback_doms. |
| */ |
| static cpumask_var_t fallback_doms; |
| |
| /* |
| * arch_update_cpu_topology lets virtualized architectures update the |
| * CPU core maps. It is supposed to return 1 if the topology changed |
| * or 0 if it stayed the same. |
| */ |
| int __weak arch_update_cpu_topology(void) |
| { |
| return 0; |
| } |
| |
| cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
| { |
| int i; |
| cpumask_var_t *doms; |
| |
| doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); |
| if (!doms) |
| return NULL; |
| for (i = 0; i < ndoms; i++) { |
| if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { |
| free_sched_domains(doms, i); |
| return NULL; |
| } |
| } |
| return doms; |
| } |
| |
| void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) |
| { |
| unsigned int i; |
| for (i = 0; i < ndoms; i++) |
| free_cpumask_var(doms[i]); |
| kfree(doms); |
| } |
| |
| /* |
| * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
| * For now this just excludes isolated CPUs, but could be used to |
| * exclude other special cases in the future. |
| */ |
| int sched_init_domains(const struct cpumask *cpu_map) |
| { |
| int err; |
| |
| zalloc_cpumask_var(&sched_domains_tmpmask, GFP_KERNEL); |
| zalloc_cpumask_var(&sched_domains_tmpmask2, GFP_KERNEL); |
| zalloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
| |
| arch_update_cpu_topology(); |
| ndoms_cur = 1; |
| doms_cur = alloc_sched_domains(ndoms_cur); |
| if (!doms_cur) |
| doms_cur = &fallback_doms; |
| cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); |
| err = build_sched_domains(doms_cur[0], NULL); |
| register_sched_domain_sysctl(); |
| |
| return err; |
| } |
| |
| /* |
| * Detach sched domains from a group of CPUs specified in cpu_map |
| * These CPUs will now be attached to the NULL domain |
| */ |
| static void detach_destroy_domains(const struct cpumask *cpu_map) |
| { |
| int i; |
| |
| rcu_read_lock(); |
| for_each_cpu(i, cpu_map) |
| cpu_attach_domain(NULL, &def_root_domain, i); |
| rcu_read_unlock(); |
| } |
| |
| /* handle null as "default" */ |
| static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, |
| struct sched_domain_attr *new, int idx_new) |
| { |
| struct sched_domain_attr tmp; |
| |
| /* Fast path: */ |
| if (!new && !cur) |
| return 1; |
| |
| tmp = SD_ATTR_INIT; |
| return !memcmp(cur ? (cur + idx_cur) : &tmp, |
| new ? (new + idx_new) : &tmp, |
| sizeof(struct sched_domain_attr)); |
| } |
| |
| /* |
| * Partition sched domains as specified by the 'ndoms_new' |
| * cpumasks in the array doms_new[] of cpumasks. This compares |
| * doms_new[] to the current sched domain partitioning, doms_cur[]. |
| * It destroys each deleted domain and builds each new domain. |
| * |
| * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
| * The masks don't intersect (don't overlap.) We should setup one |
| * sched domain for each mask. CPUs not in any of the cpumasks will |
| * not be load balanced. If the same cpumask appears both in the |
| * current 'doms_cur' domains and in the new 'doms_new', we can leave |
| * it as it is. |
| * |
| * The passed in 'doms_new' should be allocated using |
| * alloc_sched_domains. This routine takes ownership of it and will |
| * free_sched_domains it when done with it. If the caller failed the |
| * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, |
| * and partition_sched_domains() will fallback to the single partition |
| * 'fallback_doms', it also forces the domains to be rebuilt. |
| * |
| * If doms_new == NULL it will be replaced with cpu_online_mask. |
| * ndoms_new == 0 is a special case for destroying existing domains, |
| * and it will not create the default domain. |
| * |
| * Call with hotplug lock held |
| */ |
| void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
| struct sched_domain_attr *dattr_new) |
| { |
| int i, j, n; |
| int new_topology; |
| |
| mutex_lock(&sched_domains_mutex); |
| |
| /* Always unregister in case we don't destroy any domains: */ |
| unregister_sched_domain_sysctl(); |
| |
| /* Let the architecture update CPU core mappings: */ |
| new_topology = arch_update_cpu_topology(); |
| |
| n = doms_new ? ndoms_new : 0; |
| |
| /* Destroy deleted domains: */ |
| for (i = 0; i < ndoms_cur; i++) { |
| for (j = 0; j < n && !new_topology; j++) { |
| if (cpumask_equal(doms_cur[i], doms_new[j]) |
| && dattrs_equal(dattr_cur, i, dattr_new, j)) |
| goto match1; |
| } |
| /* No match - a current sched domain not in new doms_new[] */ |
| detach_destroy_domains(doms_cur[i]); |
| match1: |
| ; |
| } |
| |
| n = ndoms_cur; |
| if (doms_new == NULL) { |
| n = 0; |
| doms_new = &fallback_doms; |
| cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
| WARN_ON_ONCE(dattr_new); |
| } |
| |
| /* Build new domains: */ |
| for (i = 0; i < ndoms_new; i++) { |
| for (j = 0; j < n && !new_topology; j++) { |
| if (cpumask_equal(doms_new[i], doms_cur[j]) |
| && dattrs_equal(dattr_new, i, dattr_cur, j)) |
| goto match2; |
| } |
| /* No match - add a new doms_new */ |
| build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
| match2: |
| ; |
| } |
| |
| /* Remember the new sched domains: */ |
| if (doms_cur != &fallback_doms) |
| free_sched_domains(doms_cur, ndoms_cur); |
| |
| kfree(dattr_cur); |
| doms_cur = doms_new; |
| dattr_cur = dattr_new; |
| ndoms_cur = ndoms_new; |
| |
| register_sched_domain_sysctl(); |
| |
| mutex_unlock(&sched_domains_mutex); |
| } |
| |