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-rw-r--r--kernel/sched/core.c420
1 files changed, 218 insertions, 202 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d2e2e173d8f7..d833cc94eedc 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -693,8 +693,6 @@ int tg_nop(struct task_group *tg, void *data)
}
#endif
-void update_cpu_load(struct rq *this_rq);
-
static void set_load_weight(struct task_struct *p)
{
int prio = p->static_prio - MAX_RT_PRIO;
@@ -2481,22 +2479,13 @@ decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
* scheduler tick (TICK_NSEC). With tickless idle this will not be called
* every tick. We fix it up based on jiffies.
*/
-void update_cpu_load(struct rq *this_rq)
+static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
+ unsigned long pending_updates)
{
- unsigned long this_load = this_rq->load.weight;
- unsigned long curr_jiffies = jiffies;
- unsigned long pending_updates;
int i, scale;
this_rq->nr_load_updates++;
- /* Avoid repeated calls on same jiffy, when moving in and out of idle */
- if (curr_jiffies == this_rq->last_load_update_tick)
- return;
-
- pending_updates = curr_jiffies - this_rq->last_load_update_tick;
- this_rq->last_load_update_tick = curr_jiffies;
-
/* Update our load: */
this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
@@ -2521,9 +2510,45 @@ void update_cpu_load(struct rq *this_rq)
sched_avg_update(this_rq);
}
+/*
+ * Called from nohz_idle_balance() to update the load ratings before doing the
+ * idle balance.
+ */
+void update_idle_cpu_load(struct rq *this_rq)
+{
+ unsigned long curr_jiffies = jiffies;
+ unsigned long load = this_rq->load.weight;
+ unsigned long pending_updates;
+
+ /*
+ * Bloody broken means of dealing with nohz, but better than nothing..
+ * jiffies is updated by one cpu, another cpu can drift wrt the jiffy
+ * update and see 0 difference the one time and 2 the next, even though
+ * we ticked at roughtly the same rate.
+ *
+ * Hence we only use this from nohz_idle_balance() and skip this
+ * nonsense when called from the scheduler_tick() since that's
+ * guaranteed a stable rate.
+ */
+ if (load || curr_jiffies == this_rq->last_load_update_tick)
+ return;
+
+ pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+ this_rq->last_load_update_tick = curr_jiffies;
+
+ __update_cpu_load(this_rq, load, pending_updates);
+}
+
+/*
+ * Called from scheduler_tick()
+ */
static void update_cpu_load_active(struct rq *this_rq)
{
- update_cpu_load(this_rq);
+ /*
+ * See the mess in update_idle_cpu_load().
+ */
+ this_rq->last_load_update_tick = jiffies;
+ __update_cpu_load(this_rq, this_rq->load.weight, 1);
calc_load_account_active(this_rq);
}
@@ -3108,6 +3133,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
if (irqs_disabled())
print_irqtrace_events(prev);
dump_stack();
+ add_taint(TAINT_WARN);
}
/*
@@ -5555,7 +5581,8 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
break;
}
- if (cpumask_intersects(groupmask, sched_group_cpus(group))) {
+ if (!(sd->flags & SD_OVERLAP) &&
+ cpumask_intersects(groupmask, sched_group_cpus(group))) {
printk(KERN_CONT "\n");
printk(KERN_ERR "ERROR: repeated CPUs\n");
break;
@@ -5893,99 +5920,11 @@ static int __init isolated_cpu_setup(char *str)
__setup("isolcpus=", isolated_cpu_setup);
-#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, nodemask_t *used_nodes)
-{
- int i, n, val, min_val, best_node = -1;
-
- min_val = INT_MAX;
-
- for (i = 0; i < nr_node_ids; i++) {
- /* Start at @node */
- n = (node + i) % nr_node_ids;
-
- if (!nr_cpus_node(n))
- continue;
-
- /* Skip already used nodes */
- if (node_isset(n, *used_nodes))
- continue;
-
- /* Simple min distance search */
- val = node_distance(node, n);
-
- if (val < min_val) {
- min_val = val;
- best_node = n;
- }
- }
-
- if (best_node != -1)
- node_set(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
- * @span: resulting cpumask
- *
- * 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 void sched_domain_node_span(int node, struct cpumask *span)
-{
- nodemask_t used_nodes;
- int i;
-
- cpumask_clear(span);
- nodes_clear(used_nodes);
-
- cpumask_or(span, span, cpumask_of_node(node));
- node_set(node, used_nodes);
-
- for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
- int next_node = find_next_best_node(node, &used_nodes);
- if (next_node < 0)
- break;
- cpumask_or(span, span, cpumask_of_node(next_node));
- }
-}
-
-static const struct cpumask *cpu_node_mask(int cpu)
-{
- lockdep_assert_held(&sched_domains_mutex);
-
- sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask);
-
- return sched_domains_tmpmask;
-}
-
-static const struct cpumask *cpu_allnodes_mask(int cpu)
-{
- return cpu_possible_mask;
-}
-#endif /* CONFIG_NUMA */
-
static const struct cpumask *cpu_cpu_mask(int cpu)
{
return cpumask_of_node(cpu_to_node(cpu));
}
-int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
-
struct sd_data {
struct sched_domain **__percpu sd;
struct sched_group **__percpu sg;
@@ -6015,6 +5954,7 @@ struct sched_domain_topology_level {
sched_domain_init_f init;
sched_domain_mask_f mask;
int flags;
+ int numa_level;
struct sd_data data;
};
@@ -6206,10 +6146,6 @@ sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \
}
SD_INIT_FUNC(CPU)
-#ifdef CONFIG_NUMA
- SD_INIT_FUNC(ALLNODES)
- SD_INIT_FUNC(NODE)
-#endif
#ifdef CONFIG_SCHED_SMT
SD_INIT_FUNC(SIBLING)
#endif
@@ -6331,15 +6267,184 @@ static struct sched_domain_topology_level default_topology[] = {
{ sd_init_BOOK, cpu_book_mask, },
#endif
{ sd_init_CPU, cpu_cpu_mask, },
-#ifdef CONFIG_NUMA
- { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, },
- { sd_init_ALLNODES, cpu_allnodes_mask, },
-#endif
{ NULL, },
};
static struct sched_domain_topology_level *sched_domain_topology = default_topology;
+#ifdef CONFIG_NUMA
+
+static int sched_domains_numa_levels;
+static int sched_domains_numa_scale;
+static int *sched_domains_numa_distance;
+static struct cpumask ***sched_domains_numa_masks;
+static int sched_domains_curr_level;
+
+static inline int sd_local_flags(int level)
+{
+ if (sched_domains_numa_distance[level] > REMOTE_DISTANCE)
+ return 0;
+
+ return SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE;
+}
+
+static struct sched_domain *
+sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
+{
+ struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu);
+ int level = tl->numa_level;
+ int sd_weight = cpumask_weight(
+ sched_domains_numa_masks[level][cpu_to_node(cpu)]);
+
+ *sd = (struct sched_domain){
+ .min_interval = sd_weight,
+ .max_interval = 2*sd_weight,
+ .busy_factor = 32,
+ .imbalance_pct = 125,
+ .cache_nice_tries = 2,
+ .busy_idx = 3,
+ .idle_idx = 2,
+ .newidle_idx = 0,
+ .wake_idx = 0,
+ .forkexec_idx = 0,
+
+ .flags = 1*SD_LOAD_BALANCE
+ | 1*SD_BALANCE_NEWIDLE
+ | 0*SD_BALANCE_EXEC
+ | 0*SD_BALANCE_FORK
+ | 0*SD_BALANCE_WAKE
+ | 0*SD_WAKE_AFFINE
+ | 0*SD_PREFER_LOCAL
+ | 0*SD_SHARE_CPUPOWER
+ | 0*SD_SHARE_PKG_RESOURCES
+ | 1*SD_SERIALIZE
+ | 0*SD_PREFER_SIBLING
+ | sd_local_flags(level)
+ ,
+ .last_balance = jiffies,
+ .balance_interval = sd_weight,
+ };
+ SD_INIT_NAME(sd, NUMA);
+ sd->private = &tl->data;
+
+ /*
+ * Ugly hack to pass state to sd_numa_mask()...
+ */
+ sched_domains_curr_level = tl->numa_level;
+
+ return sd;
+}
+
+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_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_scale = curr_distance;
+ 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.
+ *
+ * XXX: could be optimized to O(n log n) by using sort()
+ */
+ next_distance = curr_distance;
+ for (i = 0; i < nr_node_ids; i++) {
+ for (j = 0; j < nr_node_ids; j++) {
+ int distance = node_distance(0, j);
+ if (distance > curr_distance &&
+ (distance < next_distance ||
+ next_distance == curr_distance))
+ next_distance = distance;
+ }
+ if (next_distance != curr_distance) {
+ sched_domains_numa_distance[level++] = next_distance;
+ sched_domains_numa_levels = level;
+ curr_distance = next_distance;
+ } else break;
+ }
+ /*
+ * 'level' contains the number of unique distances, excluding the
+ * identity distance node_distance(i,i).
+ *
+ * The sched_domains_nume_distance[] array includes the actual distance
+ * numbers.
+ */
+
+ 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_node(cpumask_size(), GFP_KERNEL, j);
+ if (!mask)
+ return;
+
+ sched_domains_numa_masks[i][j] = mask;
+
+ for (k = 0; k < nr_node_ids; k++) {
+ if (node_distance(j, k) > sched_domains_numa_distance[i])
+ continue;
+
+ cpumask_or(mask, mask, cpumask_of_node(k));
+ }
+ }
+ }
+
+ tl = kzalloc((ARRAY_SIZE(default_topology) + level) *
+ sizeof(struct sched_domain_topology_level), GFP_KERNEL);
+ if (!tl)
+ return;
+
+ /*
+ * Copy the default topology bits..
+ */
+ for (i = 0; default_topology[i].init; i++)
+ tl[i] = default_topology[i];
+
+ /*
+ * .. and append 'j' levels of NUMA goodness.
+ */
+ for (j = 0; j < level; i++, j++) {
+ tl[i] = (struct sched_domain_topology_level){
+ .init = sd_numa_init,
+ .mask = sd_numa_mask,
+ .flags = SDTL_OVERLAP,
+ .numa_level = j,
+ };
+ }
+
+ sched_domain_topology = tl;
+}
+#else
+static inline void sched_init_numa(void)
+{
+}
+#endif /* CONFIG_NUMA */
+
static int __sdt_alloc(const struct cpumask *cpu_map)
{
struct sched_domain_topology_level *tl;
@@ -6707,97 +6812,6 @@ match2:
mutex_unlock(&sched_domains_mutex);
}
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-static void reinit_sched_domains(void)
-{
- get_online_cpus();
-
- /* Destroy domains first to force the rebuild */
- partition_sched_domains(0, NULL, NULL);
-
- rebuild_sched_domains();
- put_online_cpus();
-}
-
-static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
-{
- unsigned int level = 0;
-
- if (sscanf(buf, "%u", &level) != 1)
- return -EINVAL;
-
- /*
- * level is always be positive so don't check for
- * level < POWERSAVINGS_BALANCE_NONE which is 0
- * What happens on 0 or 1 byte write,
- * need to check for count as well?
- */
-
- if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
- return -EINVAL;
-
- if (smt)
- sched_smt_power_savings = level;
- else
- sched_mc_power_savings = level;
-
- reinit_sched_domains();
-
- return count;
-}
-
-#ifdef CONFIG_SCHED_MC
-static ssize_t sched_mc_power_savings_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", sched_mc_power_savings);
-}
-static ssize_t sched_mc_power_savings_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- return sched_power_savings_store(buf, count, 0);
-}
-static DEVICE_ATTR(sched_mc_power_savings, 0644,
- sched_mc_power_savings_show,
- sched_mc_power_savings_store);
-#endif
-
-#ifdef CONFIG_SCHED_SMT
-static ssize_t sched_smt_power_savings_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- return sprintf(buf, "%u\n", sched_smt_power_savings);
-}
-static ssize_t sched_smt_power_savings_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- return sched_power_savings_store(buf, count, 1);
-}
-static DEVICE_ATTR(sched_smt_power_savings, 0644,
- sched_smt_power_savings_show,
- sched_smt_power_savings_store);
-#endif
-
-int __init sched_create_sysfs_power_savings_entries(struct device *dev)
-{
- int err = 0;
-
-#ifdef CONFIG_SCHED_SMT
- if (smt_capable())
- err = device_create_file(dev, &dev_attr_sched_smt_power_savings);
-#endif
-#ifdef CONFIG_SCHED_MC
- if (!err && mc_capable())
- err = device_create_file(dev, &dev_attr_sched_mc_power_savings);
-#endif
- return err;
-}
-#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
-
/*
* Update cpusets according to cpu_active mask. If cpusets are
* disabled, cpuset_update_active_cpus() becomes a simple wrapper
@@ -6835,6 +6849,8 @@ void __init sched_init_smp(void)
alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
+ sched_init_numa();
+
get_online_cpus();
mutex_lock(&sched_domains_mutex);
init_sched_domains(cpu_active_mask);