diff options
Diffstat (limited to 'kernel/sched/topology.c')
| -rw-r--r-- | kernel/sched/topology.c | 111 |
1 files changed, 95 insertions, 16 deletions
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 56a0fed30c0a..9d74371e4aad 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -7,8 +7,8 @@ DEFINE_MUTEX(sched_domains_mutex); /* Protected by sched_domains_mutex: */ -cpumask_var_t sched_domains_tmpmask; -cpumask_var_t sched_domains_tmpmask2; +static cpumask_var_t sched_domains_tmpmask; +static cpumask_var_t sched_domains_tmpmask2; #ifdef CONFIG_SCHED_DEBUG @@ -398,6 +398,7 @@ 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); +DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); static void update_top_cache_domain(int cpu) { @@ -692,6 +693,7 @@ static void init_overlap_sched_group(struct sched_domain *sd, sg_span = sched_group_span(sg); sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); sg->sgc->min_capacity = SCHED_CAPACITY_SCALE; + sg->sgc->max_capacity = SCHED_CAPACITY_SCALE; } static int @@ -851,6 +853,7 @@ static struct sched_group *get_group(int cpu, struct sd_data *sdd) sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sched_group_span(sg)); sg->sgc->min_capacity = SCHED_CAPACITY_SCALE; + sg->sgc->max_capacity = SCHED_CAPACITY_SCALE; return sg; } @@ -1061,7 +1064,6 @@ static struct cpumask ***sched_domains_numa_masks; * 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: @@ -1073,13 +1075,12 @@ static struct cpumask ***sched_domains_numa_masks; 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 sched_domain *child, int dflags, int cpu) { struct sd_data *sdd = &tl->data; struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); @@ -1100,6 +1101,9 @@ sd_init(struct sched_domain_topology_level *tl, "wrong sd_flags in topology description\n")) sd_flags &= ~TOPOLOGY_SD_FLAGS; + /* Apply detected topology flags */ + sd_flags |= dflags; + *sd = (struct sched_domain){ .min_interval = sd_weight, .max_interval = 2*sd_weight, @@ -1122,7 +1126,7 @@ sd_init(struct sched_domain_topology_level *tl, | 0*SD_SHARE_CPUCAPACITY | 0*SD_SHARE_PKG_RESOURCES | 0*SD_SERIALIZE - | 0*SD_PREFER_SIBLING + | 1*SD_PREFER_SIBLING | 0*SD_NUMA | sd_flags , @@ -1148,17 +1152,21 @@ sd_init(struct sched_domain_topology_level *tl, if (sd->flags & SD_ASYM_CPUCAPACITY) { struct sched_domain *t = sd; + /* + * Don't attempt to spread across CPUs of different capacities. + */ + if (sd->child) + sd->child->flags &= ~SD_PREFER_SIBLING; + 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->flags |= SD_PREFER_SIBLING; sd->imbalance_pct = 117; sd->cache_nice_tries = 1; sd->busy_idx = 2; @@ -1169,6 +1177,7 @@ sd_init(struct sched_domain_topology_level *tl, sd->busy_idx = 3; sd->idle_idx = 2; + sd->flags &= ~SD_PREFER_SIBLING; sd->flags |= SD_SERIALIZE; if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) { sd->flags &= ~(SD_BALANCE_EXEC | @@ -1178,7 +1187,6 @@ sd_init(struct sched_domain_topology_level *tl, #endif } else { - sd->flags |= SD_PREFER_SIBLING; sd->cache_nice_tries = 1; sd->busy_idx = 2; sd->idle_idx = 1; @@ -1295,7 +1303,7 @@ static void init_numa_topology_type(void) n = sched_max_numa_distance; - if (sched_domains_numa_levels <= 1) { + if (sched_domains_numa_levels <= 2) { sched_numa_topology_type = NUMA_DIRECT; return; } @@ -1380,9 +1388,6 @@ void sched_init_numa(void) break; } - if (!level) - return; - /* * 'level' contains the number of unique distances * @@ -1607,9 +1612,9 @@ static void __sdt_free(const struct cpumask *cpu_map) static 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 *child, int dflags, int cpu) { - struct sched_domain *sd = sd_init(tl, cpu_map, child, cpu); + struct sched_domain *sd = sd_init(tl, cpu_map, child, dflags, cpu); if (child) { sd->level = child->level + 1; @@ -1636,6 +1641,65 @@ static struct sched_domain *build_sched_domain(struct sched_domain_topology_leve } /* + * Find the sched_domain_topology_level where all CPU capacities are visible + * for all CPUs. + */ +static struct sched_domain_topology_level +*asym_cpu_capacity_level(const struct cpumask *cpu_map) +{ + int i, j, asym_level = 0; + bool asym = false; + struct sched_domain_topology_level *tl, *asym_tl = NULL; + unsigned long cap; + + /* Is there any asymmetry? */ + cap = arch_scale_cpu_capacity(NULL, cpumask_first(cpu_map)); + + for_each_cpu(i, cpu_map) { + if (arch_scale_cpu_capacity(NULL, i) != cap) { + asym = true; + break; + } + } + + if (!asym) + return NULL; + + /* + * Examine topology from all CPU's point of views to detect the lowest + * sched_domain_topology_level where a highest capacity CPU is visible + * to everyone. + */ + for_each_cpu(i, cpu_map) { + unsigned long max_capacity = arch_scale_cpu_capacity(NULL, i); + int tl_id = 0; + + for_each_sd_topology(tl) { + if (tl_id < asym_level) + goto next_level; + + for_each_cpu_and(j, tl->mask(i), cpu_map) { + unsigned long capacity; + + capacity = arch_scale_cpu_capacity(NULL, j); + + if (capacity <= max_capacity) + continue; + + max_capacity = capacity; + asym_level = tl_id; + asym_tl = tl; + } +next_level: + tl_id++; + } + } + + return asym_tl; +} + + +/* * Build sched domains for a given set of CPUs and attach the sched domains * to the individual CPUs */ @@ -1647,18 +1711,30 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att struct s_data d; struct rq *rq = NULL; int i, ret = -ENOMEM; + struct sched_domain_topology_level *tl_asym; + bool has_asym = false; alloc_state = __visit_domain_allocation_hell(&d, cpu_map); if (alloc_state != sa_rootdomain) goto error; + tl_asym = asym_cpu_capacity_level(cpu_map); + /* 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); + int dflags = 0; + + if (tl == tl_asym) { + dflags |= SD_ASYM_CPUCAPACITY; + has_asym = true; + } + + sd = build_sched_domain(tl, cpu_map, attr, sd, dflags, i); + if (tl == sched_domain_topology) *per_cpu_ptr(d.sd, i) = sd; if (tl->flags & SDTL_OVERLAP) @@ -1707,6 +1783,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att } rcu_read_unlock(); + if (has_asym) + static_branch_enable_cpuslocked(&sched_asym_cpucapacity); + if (rq && sched_debug_enabled) { pr_info("root domain span: %*pbl (max cpu_capacity = %lu)\n", cpumask_pr_args(cpu_map), rq->rd->max_cpu_capacity); |