diff --git a/include/linux/topology.h b/include/linux/topology.h index ad03df1cc266..7634cd737061 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -48,6 +48,7 @@ int arch_update_cpu_topology(void); /* Conform to ACPI 2.0 SLIT distance definitions */ #define LOCAL_DISTANCE 10 #define REMOTE_DISTANCE 20 +#define DISTANCE_BITS 8 #ifndef node_distance #define node_distance(from,to) ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE) #endif diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 5d3675c7a76b..bf5c9bd10bfe 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -1596,66 +1596,58 @@ static void init_numa_topology_type(void) } } + +#define NR_DISTANCE_VALUES (1 << DISTANCE_BITS) + 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 + 1), GFP_KERNEL); - if (!sched_domains_numa_distance) - return; - - /* Includes NUMA identity node at level 0. */ - sched_domains_numa_distance[level++] = curr_distance; - sched_domains_numa_levels = level; + unsigned long *distance_map; + int nr_levels = 0; + int i, j; /* * 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; + distance_map = bitmap_alloc(NR_DISTANCE_VALUES, GFP_KERNEL); + if (!distance_map) + return; + + bitmap_zero(distance_map, NR_DISTANCE_VALUES); 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); + int distance = node_distance(i, j); - 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 (distance < LOCAL_DISTANCE || distance >= NR_DISTANCE_VALUES) { + sched_numa_warn("Invalid distance value range"); + return; } - 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; + bitmap_set(distance_map, distance, 1); + } + } + /* + * We can now figure out how many unique distance values there are and + * allocate memory accordingly. + */ + nr_levels = bitmap_weight(distance_map, NR_DISTANCE_VALUES); + + sched_domains_numa_distance = kcalloc(nr_levels, sizeof(int), GFP_KERNEL); + if (!sched_domains_numa_distance) { + bitmap_free(distance_map); + return; } + for (i = 0, j = 0; i < nr_levels; i++, j++) { + j = find_next_bit(distance_map, NR_DISTANCE_VALUES, j); + sched_domains_numa_distance[i] = j; + } + + bitmap_free(distance_map); + /* - * 'level' contains the number of unique distances + * 'nr_levels' contains the number of unique distances * * The sched_domains_numa_distance[] array includes the actual distance * numbers. @@ -1664,15 +1656,15 @@ void sched_init_numa(void) /* * 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 + * the array will contain less then 'nr_levels' 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. + * We reset it to 'nr_levels' at the end of this function. */ sched_domains_numa_levels = 0; - sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); + sched_domains_numa_masks = kzalloc(sizeof(void *) * nr_levels, GFP_KERNEL); if (!sched_domains_numa_masks) return; @@ -1680,7 +1672,7 @@ void sched_init_numa(void) * 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++) { + for (i = 0; i < nr_levels; i++) { sched_domains_numa_masks[i] = kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); if (!sched_domains_numa_masks[i]) @@ -1688,12 +1680,17 @@ void sched_init_numa(void) for (j = 0; j < nr_node_ids; j++) { struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); + int k; + if (!mask) return; sched_domains_numa_masks[i][j] = mask; for_each_node(k) { + if (sched_debug() && (node_distance(j, k) != node_distance(k, j))) + sched_numa_warn("Node-distance not symmetric"); + if (node_distance(j, k) > sched_domains_numa_distance[i]) continue; @@ -1705,7 +1702,7 @@ void sched_init_numa(void) /* Compute default topology size */ for (i = 0; sched_domain_topology[i].mask; i++); - tl = kzalloc((i + level + 1) * + tl = kzalloc((i + nr_levels) * sizeof(struct sched_domain_topology_level), GFP_KERNEL); if (!tl) return; @@ -1728,7 +1725,7 @@ void sched_init_numa(void) /* * .. and append 'j' levels of NUMA goodness. */ - for (j = 1; j < level; i++, j++) { + for (j = 1; j < nr_levels; i++, j++) { tl[i] = (struct sched_domain_topology_level){ .mask = sd_numa_mask, .sd_flags = cpu_numa_flags, @@ -1740,8 +1737,8 @@ void sched_init_numa(void) sched_domain_topology = tl; - sched_domains_numa_levels = level; - sched_max_numa_distance = sched_domains_numa_distance[level - 1]; + sched_domains_numa_levels = nr_levels; + sched_max_numa_distance = sched_domains_numa_distance[nr_levels - 1]; init_numa_topology_type(); }