diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 340 |
1 files changed, 286 insertions, 54 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 5f889d0cbfcc..18b95520a2e2 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1478,6 +1478,7 @@ static inline void prepare_task_switch(runqueue_t *rq, task_t *next) /** * finish_task_switch - clean up after a task-switch + * @rq: runqueue associated with task-switch * @prev: the thread we just switched away from. * * finish_task_switch must be called after the context switch, paired @@ -4779,7 +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; @@ -4802,7 +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) @@ -4830,8 +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; @@ -4864,12 +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]; @@ -4891,36 +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 @@ -4928,9 +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. @@ -4943,11 +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; @@ -4972,7 +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)) @@ -4997,8 +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 */ @@ -5017,14 +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; @@ -5039,13 +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 @@ -5058,10 +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 |
