sched/core: Add first cpu w/ max/min orig capacity to root domain

[firefly-linux-kernel-4.4.55.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 01cb249109ccaad4f9fb0b191eea0a30a72638dc..495bc41907d6288122d7ab32428eb12f82324c97 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6037,6 +6037,7 @@ static int sd_degenerate(struct sched_domain *sd)
                         SD_BALANCE_FORK |
                         SD_BALANCE_EXEC |
                         SD_SHARE_CPUCAPACITY |
+                        SD_ASYM_CPUCAPACITY |
                         SD_SHARE_PKG_RESOURCES |
                         SD_SHARE_POWERDOMAIN |
                         SD_SHARE_CAP_STATES)) {
@@ -6068,6 +6069,7 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
                                SD_BALANCE_NEWIDLE |
                                SD_BALANCE_FORK |
                                SD_BALANCE_EXEC |
+                               SD_ASYM_CPUCAPACITY |
                                SD_SHARE_CPUCAPACITY |
                                SD_SHARE_PKG_RESOURCES |
                                SD_PREFER_SIBLING |
@@ -6153,6 +6155,9 @@ static int init_rootdomain(struct root_domain *rd)
                goto free_rto_mask;
 
        init_max_cpu_capacity(&rd->max_cpu_capacity);
+
+       rd->max_cap_orig_cpu = rd->min_cap_orig_cpu = -1;
+
        return 0;
 
 free_rto_mask:
@@ -6457,6 +6462,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
                 */
                sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span);
                sg->sgc->max_capacity = SCHED_CAPACITY_SCALE;
+               sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
 
                /*
                 * Make sure the first group of this domain contains the
@@ -6749,11 +6755,19 @@ static int sched_domains_curr_level;
 /*
  * SD_flags allowed in topology descriptions.
  *
- * 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_SHARE_CAP_STATES    - describes shared capacity states
+ * 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
+ *   SD_SHARE_CAP_STATES    - describes shared capacity states
+ *
+ * Odd one out, which beside describing the topology has a quirk also
+ * prescribes the desired behaviour that goes along with it:
  *
  * Odd one out:
  * SD_ASYM_PACKING        - describes SMT quirks
@@ -6763,11 +6777,13 @@ static int sched_domains_curr_level;
         SD_SHARE_PKG_RESOURCES |       \
         SD_NUMA |                      \
         SD_ASYM_PACKING |              \
+        SD_ASYM_CPUCAPACITY |          \
         SD_SHARE_POWERDOMAIN |         \
         SD_SHARE_CAP_STATES)
 
 static struct sched_domain *
-sd_init(struct sched_domain_topology_level *tl, int cpu)
+sd_init(struct sched_domain_topology_level *tl,
+       struct sched_domain *child, int cpu)
 {
        struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu);
        int sd_weight, sd_flags = 0;
@@ -6819,6 +6835,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu)
                .smt_gain               = 0,
                .max_newidle_lb_cost    = 0,
                .next_decay_max_lb_cost = jiffies,
+               .child                  = child,
 #ifdef CONFIG_SCHED_DEBUG
                .name                   = tl->name,
 #endif
@@ -6828,6 +6845,13 @@ sd_init(struct sched_domain_topology_level *tl, int cpu)
         * 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;
@@ -7274,16 +7298,13 @@ 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);
-       if (!sd)
-               return child;
+       struct sched_domain *sd = sd_init(tl, child, cpu);
 
        cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
        if (child) {
                sd->level = child->level + 1;
                sched_domain_level_max = max(sched_domain_level_max, sd->level);
                child->parent = sd;
-               sd->child = child;
 
                if (!cpumask_subset(sched_domain_span(child),
                                    sched_domain_span(sd))) {
@@ -7314,7 +7335,6 @@ static int build_sched_domains(const struct cpumask *cpu_map,
        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);
@@ -7368,8 +7388,19 @@ static int build_sched_domains(const struct cpumask *cpu_map,
        /* Attach the domains */
        rcu_read_lock();
        for_each_cpu(i, cpu_map) {
-               rq = cpu_rq(i);
+               int max_cpu = READ_ONCE(d.rd->max_cap_orig_cpu);
+               int min_cpu = READ_ONCE(d.rd->min_cap_orig_cpu);
+
+               if ((max_cpu < 0) || (cpu_rq(i)->cpu_capacity_orig >
+                   cpu_rq(max_cpu)->cpu_capacity_orig))
+                       WRITE_ONCE(d.rd->max_cap_orig_cpu, i);
+
+               if ((min_cpu < 0) || (cpu_rq(i)->cpu_capacity_orig <
+                   cpu_rq(min_cpu)->cpu_capacity_orig))
+                       WRITE_ONCE(d.rd->min_cap_orig_cpu, i);
+
                sd = *per_cpu_ptr(d.sd, i);
+
                cpu_attach_domain(sd, d.rd, i);
        }
        rcu_read_unlock();
@@ -8956,7 +8987,6 @@ struct cgroup_subsys cpu_cgrp_subsys = {
        .fork           = cpu_cgroup_fork,
        .can_attach     = cpu_cgroup_can_attach,
        .attach         = cpu_cgroup_attach,
-       .allow_attach   = subsys_cgroup_allow_attach,
        .legacy_cftypes = cpu_files,
        .early_init     = 1,
 };