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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 18:27:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 18:27:32 -0700
commitd79ee93de909dfb252279b9a95978bbda9a814a9 (patch)
treebfccca60fd36259ff4bcc5e78a2c272fbd680065 /kernel
parent2ff2b289a695807e291e1ed9f639d8a3ba5f4254 (diff)
parent1c2927f18576d65631d8e0ddd19e1d023183222e (diff)
downloadlinux-d79ee93de909dfb252279b9a95978bbda9a814a9.tar.bz2
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar: "The biggest change is the cleanup/simplification of the load-balancer: instead of the current practice of architectures twiddling scheduler internal data structures and providing the scheduler domains in colorfully inconsistent ways, we now have generic scheduler code in kernel/sched/core.c:sched_init_numa() that looks at the architecture's node_distance() parameters and (while not fully trusting it) deducts a NUMA topology from it. This inevitably changes balancing behavior - hopefully for the better. There are various smaller optimizations, cleanups and fixlets as well" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Taint kernel with TAINT_WARN after sleep-in-atomic bug sched: Remove stale power aware scheduling remnants and dysfunctional knobs sched/debug: Fix printing large integers on 32-bit platforms sched/fair: Improve the ->group_imb logic sched/nohz: Fix rq->cpu_load[] calculations sched/numa: Don't scale the imbalance sched/fair: Revert sched-domain iteration breakage sched/x86: Rewrite set_cpu_sibling_map() sched/numa: Fix the new NUMA topology bits sched/numa: Rewrite the CONFIG_NUMA sched domain support sched/fair: Propagate 'struct lb_env' usage into find_busiest_group sched/fair: Add some serialization to the sched_domain load-balance walk sched/fair: Let minimally loaded cpu balance the group sched: Change rq->nr_running to unsigned int x86/numa: Check for nonsensical topologies on real hw as well x86/numa: Hard partition cpu topology masks on node boundaries x86/numa: Allow specifying node_distance() for numa=fake x86/sched: Make mwait_usable() heed to "idle=" kernel parameters properly sched: Update documentation and comments sched_rt: Avoid unnecessary dequeue and enqueue of pushable tasks in set_cpus_allowed_rt()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/core.c420
-rw-r--r--kernel/sched/debug.c12
-rw-r--r--kernel/sched/fair.c462
-rw-r--r--kernel/sched/idle_task.c2
-rw-r--r--kernel/sched/rt.c56
-rw-r--r--kernel/sched/sched.h8
6 files changed, 352 insertions, 608 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);
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 09acaa15161d..6f79596e0ea9 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -202,7 +202,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SPLIT_NS(spread0));
SEQ_printf(m, " .%-30s: %d\n", "nr_spread_over",
cfs_rq->nr_spread_over);
- SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
+ SEQ_printf(m, " .%-30s: %d\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
@@ -260,8 +260,14 @@ static void print_cpu(struct seq_file *m, int cpu)
SEQ_printf(m, "\ncpu#%d\n", cpu);
#endif
-#define P(x) \
- SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x))
+#define P(x) \
+do { \
+ if (sizeof(rq->x) == 4) \
+ SEQ_printf(m, " .%-30s: %ld\n", #x, (long)(rq->x)); \
+ else \
+ SEQ_printf(m, " .%-30s: %Ld\n", #x, (long long)(rq->x));\
+} while (0)
+
#define PN(x) \
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x))
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e9553640c1c3..940e6d17cf96 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2721,7 +2721,7 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
* If power savings logic is enabled for a domain, see if we
* are not overloaded, if so, don't balance wider.
*/
- if (tmp->flags & (SD_POWERSAVINGS_BALANCE|SD_PREFER_LOCAL)) {
+ if (tmp->flags & (SD_PREFER_LOCAL)) {
unsigned long power = 0;
unsigned long nr_running = 0;
unsigned long capacity;
@@ -2734,9 +2734,6 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
- if (tmp->flags & SD_POWERSAVINGS_BALANCE)
- nr_running /= 2;
-
if (nr_running < capacity)
want_sd = 0;
}
@@ -3082,7 +3079,7 @@ struct lb_env {
struct rq *dst_rq;
enum cpu_idle_type idle;
- long load_move;
+ long imbalance;
unsigned int flags;
unsigned int loop;
@@ -3218,7 +3215,7 @@ static unsigned long task_h_load(struct task_struct *p);
static const unsigned int sched_nr_migrate_break = 32;
/*
- * move_tasks tries to move up to load_move weighted load from busiest to
+ * move_tasks tries to move up to imbalance weighted load from busiest to
* this_rq, as part of a balancing operation within domain "sd".
* Returns 1 if successful and 0 otherwise.
*
@@ -3231,7 +3228,7 @@ static int move_tasks(struct lb_env *env)
unsigned long load;
int pulled = 0;
- if (env->load_move <= 0)
+ if (env->imbalance <= 0)
return 0;
while (!list_empty(tasks)) {
@@ -3257,7 +3254,7 @@ static int move_tasks(struct lb_env *env)
if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
goto next;
- if ((load / 2) > env->load_move)
+ if ((load / 2) > env->imbalance)
goto next;
if (!can_migrate_task(p, env))
@@ -3265,7 +3262,7 @@ static int move_tasks(struct lb_env *env)
move_task(p, env);
pulled++;
- env->load_move -= load;
+ env->imbalance -= load;
#ifdef CONFIG_PREEMPT
/*
@@ -3281,7 +3278,7 @@ static int move_tasks(struct lb_env *env)
* We only want to steal up to the prescribed amount of
* weighted load.
*/
- if (env->load_move <= 0)
+ if (env->imbalance <= 0)
break;
continue;
@@ -3435,14 +3432,6 @@ struct sd_lb_stats {
unsigned int busiest_group_weight;
int group_imb; /* Is there imbalance in this sd */
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
- int power_savings_balance; /* Is powersave balance needed for this sd */
- struct sched_group *group_min; /* Least loaded group in sd */
- struct sched_group *group_leader; /* Group which relieves group_min */
- unsigned long min_load_per_task; /* load_per_task in group_min */
- unsigned long leader_nr_running; /* Nr running of group_leader */
- unsigned long min_nr_running; /* Nr running of group_min */
-#endif
};
/*
@@ -3486,148 +3475,6 @@ static inline int get_sd_load_idx(struct sched_domain *sd,
return load_idx;
}
-
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-/**
- * init_sd_power_savings_stats - Initialize power savings statistics for
- * the given sched_domain, during load balancing.
- *
- * @sd: Sched domain whose power-savings statistics are to be initialized.
- * @sds: Variable containing the statistics for sd.
- * @idle: Idle status of the CPU at which we're performing load-balancing.
- */
-static inline void init_sd_power_savings_stats(struct sched_domain *sd,
- struct sd_lb_stats *sds, enum cpu_idle_type idle)
-{
- /*
- * Busy processors will not participate in power savings
- * balance.
- */
- if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE))
- sds->power_savings_balance = 0;
- else {
- sds->power_savings_balance = 1;
- sds->min_nr_running = ULONG_MAX;
- sds->leader_nr_running = 0;
- }
-}
-
-/**
- * update_sd_power_savings_stats - Update the power saving stats for a
- * sched_domain while performing load balancing.
- *
- * @group: sched_group belonging to the sched_domain under consideration.
- * @sds: Variable containing the statistics of the sched_domain
- * @local_group: Does group contain the CPU for which we're performing
- * load balancing ?
- * @sgs: Variable containing the statistics of the group.
- */
-static inline void update_sd_power_savings_stats(struct sched_group *group,
- struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs)
-{
-
- if (!sds->power_savings_balance)
- return;
-
- /*
- * If the local group is idle or completely loaded
- * no need to do power savings balance at this domain
- */
- if (local_group && (sds->this_nr_running >= sgs->group_capacity ||
- !sds->this_nr_running))
- sds->power_savings_balance = 0;
-
- /*
- * If a group is already running at full capacity or idle,
- * don't include that group in power savings calculations
- */
- if (!sds->power_savings_balance ||
- sgs->sum_nr_running >= sgs->group_capacity ||
- !sgs->sum_nr_running)
- return;
-
- /*
- * Calculate the group which has the least non-idle load.
- * This is the group from where we need to pick up the load
- * for saving power
- */
- if ((sgs->sum_nr_running < sds->min_nr_running) ||
- (sgs->sum_nr_running == sds->min_nr_running &&
- group_first_cpu(group) > group_first_cpu(sds->group_min))) {
- sds->group_min = group;
- sds->min_nr_running = sgs->sum_nr_running;
- sds->min_load_per_task = sgs->sum_weighted_load /
- sgs->sum_nr_running;
- }
-
- /*
- * Calculate the group which is almost near its
- * capacity but still has some space to pick up some load
- * from other group and save more power
- */
- if (sgs->sum_nr_running + 1 > sgs->group_capacity)
- return;
-
- if (sgs->sum_nr_running > sds->leader_nr_running ||
- (sgs->sum_nr_running == sds->leader_nr_running &&
- group_first_cpu(group) < group_first_cpu(sds->group_leader))) {
- sds->group_leader = group;
- sds->leader_nr_running = sgs->sum_nr_running;
- }
-}
-
-/**
- * check_power_save_busiest_group - see if there is potential for some power-savings balance
- * @sds: Variable containing the statistics of the sched_domain
- * under consideration.
- * @this_cpu: Cpu at which we're currently performing load-balancing.
- * @imbalance: Variable to store the imbalance.
- *
- * Description:
- * Check if we have potential to perform some power-savings balance.
- * If yes, set the busiest group to be the least loaded group in the
- * sched_domain, so that it's CPUs can be put to idle.
- *
- * Returns 1 if there is potential to perform power-savings balance.
- * Else returns 0.
- */
-static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
- int this_cpu, unsigned long *imbalance)
-{
- if (!sds->power_savings_balance)
- return 0;
-
- if (sds->this != sds->group_leader ||
- sds->group_leader == sds->group_min)
- return 0;
-
- *imbalance = sds->min_load_per_task;
- sds->busiest = sds->group_min;
-
- return 1;
-
-}
-#else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
-static inline void init_sd_power_savings_stats(struct sched_domain *sd,
- struct sd_lb_stats *sds, enum cpu_idle_type idle)
-{
- return;
-}
-
-static inline void update_sd_power_savings_stats(struct sched_group *group,
- struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs)
-{
- return;
-}
-
-static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
- int this_cpu, unsigned long *imbalance)
-{
- return 0;
-}
-#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
-
-
unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
{
return SCHED_POWER_SCALE;
@@ -3765,24 +3612,22 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
* update_sg_lb_stats - Update sched_group's statistics for load balancing.
* @sd: The sched_domain whose statistics are to be updated.
* @group: sched_group whose statistics are to be updated.
- * @this_cpu: Cpu for which load balance is currently performed.
- * @idle: Idle status of this_cpu
* @load_idx: Load index of sched_domain of this_cpu for load calc.
* @local_group: Does group contain this_cpu.
* @cpus: Set of cpus considered for load balancing.
* @balance: Should we balance.
* @sgs: variable to hold the statistics for this group.
*/
-static inline void update_sg_lb_stats(struct sched_domain *sd,
- struct sched_group *group, int this_cpu,
- enum cpu_idle_type idle, int load_idx,
+static inline void update_sg_lb_stats(struct lb_env *env,
+ struct sched_group *group, int load_idx,
int local_group, const struct cpumask *cpus,
int *balance, struct sg_lb_stats *sgs)
{
- unsigned long load, max_cpu_load, min_cpu_load, max_nr_running;
- int i;
+ unsigned long nr_running, max_nr_running, min_nr_running;
+ unsigned long load, max_cpu_load, min_cpu_load;
unsigned int balance_cpu = -1, first_idle_cpu = 0;
unsigned long avg_load_per_task = 0;
+ int i;
if (local_group)
balance_cpu = group_first_cpu(group);
@@ -3791,10 +3636,13 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
max_cpu_load = 0;
min_cpu_load = ~0UL;
max_nr_running = 0;
+ min_nr_running = ~0UL;
for_each_cpu_and(i, sched_group_cpus(group), cpus) {
struct rq *rq = cpu_rq(i);
+ nr_running = rq->nr_running;
+
/* Bias balancing toward cpus of our domain */
if (local_group) {
if (idle_cpu(i) && !first_idle_cpu) {
@@ -3805,16 +3653,19 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
load = target_load(i, load_idx);
} else {
load = source_load(i, load_idx);
- if (load > max_cpu_load) {
+ if (load > max_cpu_load)
max_cpu_load = load;
- max_nr_running = rq->nr_running;
- }
if (min_cpu_load > load)
min_cpu_load = load;
+
+ if (nr_running > max_nr_running)
+ max_nr_running = nr_running;
+ if (min_nr_running > nr_running)
+ min_nr_running = nr_running;
}
sgs->group_load += load;
- sgs->sum_nr_running += rq->nr_running;
+ sgs->sum_nr_running += nr_running;
sgs->sum_weighted_load += weighted_cpuload(i);
if (idle_cpu(i))
sgs->idle_cpus++;
@@ -3827,14 +3678,14 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
* to do the newly idle load balance.
*/
if (local_group) {
- if (idle != CPU_NEWLY_IDLE) {
- if (balance_cpu != this_cpu) {
+ if (env->idle != CPU_NEWLY_IDLE) {
+ if (balance_cpu != env->dst_cpu) {
*balance = 0;
return;
}
- update_group_power(sd, this_cpu);
+ update_group_power(env->sd, env->dst_cpu);
} else if (time_after_eq(jiffies, group->sgp->next_update))
- update_group_power(sd, this_cpu);
+ update_group_power(env->sd, env->dst_cpu);
}
/* Adjust by relative CPU power of the group */
@@ -3852,13 +3703,14 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
if (sgs->sum_nr_running)
avg_load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
- if ((max_cpu_load - min_cpu_load) >= avg_load_per_task && max_nr_running > 1)
+ if ((max_cpu_load - min_cpu_load) >= avg_load_per_task &&
+ (max_nr_running - min_nr_running) > 1)
sgs->group_imb = 1;
sgs->group_capacity = DIV_ROUND_CLOSEST(group->sgp->power,
SCHED_POWER_SCALE);
if (!sgs->group_capacity)
- sgs->group_capacity = fix_small_capacity(sd, group);
+ sgs->group_capacity = fix_small_capacity(env->sd, group);
sgs->group_weight = group->group_weight;
if (sgs->group_capacity > sgs->sum_nr_running)
@@ -3876,11 +3728,10 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
* Determine if @sg is a busier group than the previously selected
* busiest group.
*/
-static bool update_sd_pick_busiest(struct sched_domain *sd,
+static bool update_sd_pick_busiest(struct lb_env *env,
struct sd_lb_stats *sds,
struct sched_group *sg,
- struct sg_lb_stats *sgs,
- int this_cpu)
+ struct sg_lb_stats *sgs)
{
if (sgs->avg_load <= sds->max_load)
return false;
@@ -3896,8 +3747,8 @@ static bool update_sd_pick_busiest(struct sched_domain *sd,
* numbered CPUs in the group, therefore mark all groups
* higher than ourself as busy.
*/
- if ((sd->flags & SD_ASYM_PACKING) && sgs->sum_nr_running &&
- this_cpu < group_first_cpu(sg)) {
+ if ((env->sd->flags & SD_ASYM_PACKING) && sgs->sum_nr_running &&
+ env->dst_cpu < group_first_cpu(sg)) {
if (!sds->busiest)
return true;
@@ -3917,28 +3768,27 @@ static bool update_sd_pick_busiest(struct sched_domain *sd,
* @balance: Should we balance.
* @sds: variable to hold the statistics for this sched_domain.
*/
-static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
- enum cpu_idle_type idle, const struct cpumask *cpus,
- int *balance, struct sd_lb_stats *sds)
+static inline void update_sd_lb_stats(struct lb_env *env,
+ const struct cpumask *cpus,
+ int *balance, struct sd_lb_stats *sds)
{
- struct sched_domain *child = sd->child;
- struct sched_group *sg = sd->groups;
+ struct sched_domain *child = env->sd->child;
+ struct sched_group *sg = env->sd->groups;
struct sg_lb_stats sgs;
int load_idx, prefer_sibling = 0;
if (child && child->flags & SD_PREFER_SIBLING)
prefer_sibling = 1;
- init_sd_power_savings_stats(sd, sds, idle);
- load_idx = get_sd_load_idx(sd, idle);
+ load_idx = get_sd_load_idx(env->sd, env->idle);
do {
int local_group;
- local_group = cpumask_test_cpu(this_cpu, sched_group_cpus(sg));
+ local_group = cpumask_test_cpu(env->dst_cpu, sched_group_cpus(sg));
memset(&sgs, 0, sizeof(sgs));
- update_sg_lb_stats(sd, sg, this_cpu, idle, load_idx,
- local_group, cpus, balance, &sgs);
+ update_sg_lb_stats(env, sg, load_idx, local_group,
+ cpus, balance, &sgs);
if (local_group && !(*balance))
return;
@@ -3966,7 +3816,7 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
sds->this_load_per_task = sgs.sum_weighted_load;
sds->this_has_capacity = sgs.group_has_capacity;
sds->this_idle_cpus = sgs.idle_cpus;
- } else if (update_sd_pick_busiest(sd, sds, sg, &sgs, this_cpu)) {
+ } else if (update_sd_pick_busiest(env, sds, sg, &sgs)) {
sds->max_load = sgs.avg_load;
sds->busiest = sg;
sds->busiest_nr_running = sgs.sum_nr_running;
@@ -3978,9 +3828,8 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
sds->group_imb = sgs.group_imb;
}
- update_sd_power_savings_stats(sg, sds, local_group, &sgs);
sg = sg->next;
- } while (sg != sd->groups);
+ } while (sg != env->sd->groups);
}
/**
@@ -4008,24 +3857,23 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
* @this_cpu: The cpu at whose sched_domain we're performing load-balance.
* @imbalance: returns amount of imbalanced due to packing.
*/
-static int check_asym_packing(struct sched_domain *sd,
- struct sd_lb_stats *sds,
- int this_cpu, unsigned long *imbalance)
+static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
{
int busiest_cpu;
- if (!(sd->flags & SD_ASYM_PACKING))
+ if (!(env->sd->flags & SD_ASYM_PACKING))
return 0;
if (!sds->busiest)
return 0;
busiest_cpu = group_first_cpu(sds->busiest);
- if (this_cpu > busiest_cpu)
+ if (env->dst_cpu > busiest_cpu)
return 0;
- *imbalance = DIV_ROUND_CLOSEST(sds->max_load * sds->busiest->sgp->power,
- SCHED_POWER_SCALE);
+ env->imbalance = DIV_ROUND_CLOSEST(
+ sds->max_load * sds->busiest->sgp->power, SCHED_POWER_SCALE);
+
return 1;
}
@@ -4037,8 +3885,8 @@ static int check_asym_packing(struct sched_domain *sd,
* @this_cpu: The cpu at whose sched_domain we're performing load-balance.
* @imbalance: Variable to store the imbalance.
*/
-static inline void fix_small_imbalance(struct sd_lb_stats *sds,
- int this_cpu, unsigned long *imbalance)
+static inline
+void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
{
unsigned long tmp, pwr_now = 0, pwr_move = 0;
unsigned int imbn = 2;
@@ -4049,9 +3897,10 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
if (sds->busiest_load_per_task >
sds->this_load_per_task)
imbn = 1;
- } else
+ } else {
sds->this_load_per_task =
- cpu_avg_load_per_task(this_cpu);
+ cpu_avg_load_per_task(env->dst_cpu);
+ }
scaled_busy_load_per_task = sds->busiest_load_per_task
* SCHED_POWER_SCALE;
@@ -4059,7 +3908,7 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
if (sds->max_load - sds->this_load + scaled_busy_load_per_task >=
(scaled_busy_load_per_task * imbn)) {
- *imbalance = sds->busiest_load_per_task;
+ env->imbalance = sds->busiest_load_per_task;
return;
}
@@ -4096,18 +3945,16 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
/* Move if we gain throughput */
if (pwr_move > pwr_now)
- *imbalance = sds->busiest_load_per_task;
+ env->imbalance = sds->busiest_load_per_task;
}
/**
* calculate_imbalance - Calculate the amount of imbalance present within the
* groups of a given sched_domain during load balance.
+ * @env: load balance environment
* @sds: statistics of the sched_domain whose imbalance is to be calculated.
- * @this_cpu: Cpu for which currently load balance is being performed.
- * @imbalance: The variable to store the imbalance.
*/
-static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
- unsigned long *imbalance)
+static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
{
unsigned long max_pull, load_above_capacity = ~0UL;
@@ -4123,8 +3970,8 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
* its cpu_power, while calculating max_load..)
*/
if (sds->max_load < sds->avg_load) {
- *imbalance = 0;
- return fix_small_imbalance(sds, this_cpu, imbalance);
+ env->imbalance = 0;
+ return fix_small_imbalance(env, sds);
}
if (!sds->group_imb) {
@@ -4152,7 +3999,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
max_pull = min(sds->max_load - sds->avg_load, load_above_capacity);
/* How much load to actually move to equalise the imbalance */
- *imbalance = min(max_pull * sds->busiest->sgp->power,
+ env->imbalance = min(max_pull * sds->busiest->sgp->power,
(sds->avg_load - sds->this_load) * sds->this->sgp->power)
/ SCHED_POWER_SCALE;
@@ -4162,8 +4009,8 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
* a think about bumping its value to force at least one task to be
* moved
*/
- if (*imbalance < sds->busiest_load_per_task)
- return fix_small_imbalance(sds, this_cpu, imbalance);
+ if (env->imbalance < sds->busiest_load_per_task)
+ return fix_small_imbalance(env, sds);
}
@@ -4194,9 +4041,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
* put to idle by rebalancing its tasks onto our group.
*/
static struct sched_group *
-find_busiest_group(struct sched_domain *sd, int this_cpu,
- unsigned long *imbalance, enum cpu_idle_type idle,
- const struct cpumask *cpus, int *balance)
+find_busiest_group(struct lb_env *env, const struct cpumask *cpus, int *balance)
{
struct sd_lb_stats sds;
@@ -4206,7 +4051,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
* Compute the various statistics relavent for load balancing at
* this level.
*/
- update_sd_lb_stats(sd, this_cpu, idle, cpus, balance, &sds);
+ update_sd_lb_stats(env, cpus, balance, &sds);
/*
* this_cpu is not the appropriate cpu to perform load balancing at
@@ -4215,8 +4060,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
if (!(*balance))
goto ret;
- if ((idle == CPU_IDLE || idle == CPU_NEWLY_IDLE) &&
- check_asym_packing(sd, &sds, this_cpu, imbalance))
+ if ((env->idle == CPU_IDLE || env->idle == CPU_NEWLY_IDLE) &&
+ check_asym_packing(env, &sds))
return sds.busiest;
/* There is no busy sibling group to pull tasks from */
@@ -4234,7 +4079,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
goto force_balance;
/* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */
- if (idle == CPU_NEWLY_IDLE && sds.this_has_capacity &&
+ if (env->idle == CPU_NEWLY_IDLE && sds.this_has_capacity &&
!sds.busiest_has_capacity)
goto force_balance;
@@ -4252,7 +4097,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
if (sds.this_load >= sds.avg_load)
goto out_balanced;
- if (idle == CPU_IDLE) {
+ if (env->idle == CPU_IDLE) {
/*
* This cpu is idle. If the busiest group load doesn't
* have more tasks than the number of available cpu's and
@@ -4267,34 +4112,27 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
* In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use
* imbalance_pct to be conservative.
*/
- if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
+ if (100 * sds.max_load <= env->sd->imbalance_pct * sds.this_load)
goto out_balanced;
}
force_balance:
/* Looks like there is an imbalance. Compute it */
- calculate_imbalance(&sds, this_cpu, imbalance);
+ calculate_imbalance(env, &sds);
return sds.busiest;
out_balanced:
- /*
- * There is no obvious imbalance. But check if we can do some balancing
- * to save power.
- */
- if (check_power_save_busiest_group(&sds, this_cpu, imbalance))
- return sds.busiest;
ret:
- *imbalance = 0;
+ env->imbalance = 0;
return NULL;
}
/*
* find_busiest_queue - find the busiest runqueue among the cpus in group.
*/
-static struct rq *
-find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
- enum cpu_idle_type idle, unsigned long imbalance,
- const struct cpumask *cpus)
+static struct rq *find_busiest_queue(struct lb_env *env,
+ struct sched_group *group,
+ const struct cpumask *cpus)
{
struct rq *busiest = NULL, *rq;
unsigned long max_load = 0;
@@ -4307,7 +4145,7 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
unsigned long wl;
if (!capacity)
- capacity = fix_small_capacity(sd, group);
+ capacity = fix_small_capacity(env->sd, group);
if (!cpumask_test_cpu(i, cpus))
continue;
@@ -4319,7 +4157,7 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
* When comparing with imbalance, use weighted_cpuload()
* which is not scaled with the cpu power.
*/
- if (capacity && rq->nr_running == 1 && wl > imbalance)
+ if (capacity && rq->nr_running == 1 && wl > env->imbalance)
continue;
/*
@@ -4348,40 +4186,19 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
/* Working cpumask for load_balance and load_balance_newidle. */
DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
-static int need_active_balance(struct sched_domain *sd, int idle,
- int busiest_cpu, int this_cpu)
+static int need_active_balance(struct lb_env *env)
{
- if (idle == CPU_NEWLY_IDLE) {
+ struct sched_domain *sd = env->sd;
+
+ if (env->idle == CPU_NEWLY_IDLE) {
/*
* ASYM_PACKING needs to force migrate tasks from busy but
* higher numbered CPUs in order to pack all tasks in the
* lowest numbered CPUs.
*/
- if ((sd->flags & SD_ASYM_PACKING) && busiest_cpu > this_cpu)
+ if ((sd->flags & SD_ASYM_PACKING) && env->src_cpu > env->dst_cpu)
return 1;
-
- /*
- * The only task running in a non-idle cpu can be moved to this
- * cpu in an attempt to completely freeup the other CPU
- * package.
- *
- * The package power saving logic comes from
- * find_busiest_group(). If there are no imbalance, then
- * f_b_g() will return NULL. However when sched_mc={1,2} then
- * f_b_g() will select a group from which a running task may be
- * pulled to this cpu in order to make the other package idle.
- * If there is no opportunity to make a package idle and if
- * there are no imbalance, then f_b_g() will return NULL and no
- * action will be taken in load_balance_newidle().
- *
- * Under normal task pull operation due to imbalance, there
- * will be more than one task in the source run queue and
- * move_tasks() will succeed. ld_moved will be true and this
- * active balance code will not be triggered.
- */
- if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP)
- return 0;
}
return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
@@ -4399,7 +4216,6 @@ static int load_balance(int this_cpu, struct rq *this_rq,
{
int ld_moved, active_balance = 0;
struct sched_group *group;
- unsigned long imbalance;
struct rq *busiest;
unsigned long flags;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
@@ -4417,8 +4233,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
schedstat_inc(sd, lb_count[idle]);
redo:
- group = find_busiest_group(sd, this_cpu, &imbalance, idle,
- cpus, balance);
+ group = find_busiest_group(&env, cpus, balance);
if (*balance == 0)
goto out_balanced;
@@ -4428,7 +4243,7 @@ redo:
goto out_balanced;
}
- busiest = find_busiest_queue(sd, group, idle, imbalance, cpus);
+ busiest = find_busiest_queue(&env, group, cpus);
if (!busiest) {
schedstat_inc(sd, lb_nobusyq[idle]);
goto out_balanced;
@@ -4436,7 +4251,7 @@ redo:
BUG_ON(busiest == this_rq);
- schedstat_add(sd, lb_imbalance[idle], imbalance);
+ schedstat_add(sd, lb_imbalance[idle], env.imbalance);
ld_moved = 0;
if (busiest->nr_running > 1) {
@@ -4447,10 +4262,9 @@ redo:
* correctly treated as an imbalance.
*/
env.flags |= LBF_ALL_PINNED;
- env.load_move = imbalance;
- env.src_cpu = busiest->cpu;
- env.src_rq = busiest;
- env.loop_max = min_t(unsigned long, sysctl_sched_nr_migrate, busiest->nr_running);
+ env.src_cpu = busiest->cpu;
+ env.src_rq = busiest;
+ env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
more_balance:
local_irq_save(flags);
@@ -4492,7 +4306,7 @@ more_balance:
if (idle != CPU_NEWLY_IDLE)
sd->nr_balance_failed++;
- if (need_active_balance(sd, idle, cpu_of(busiest), this_cpu)) {
+ if (need_active_balance(&env)) {
raw_spin_lock_irqsave(&busiest->lock, flags);
/* don't kick the active_load_balance_cpu_stop,
@@ -4519,10 +4333,11 @@ more_balance:
}
raw_spin_unlock_irqrestore(&busiest->lock, flags);
- if (active_balance)
+ if (active_balance) {
stop_one_cpu_nowait(cpu_of(busiest),
active_load_balance_cpu_stop, busiest,
&busiest->active_balance_work);
+ }
/*
* We've kicked active balancing, reset the failure
@@ -4703,104 +4518,15 @@ static struct {
unsigned long next_balance; /* in jiffy units */
} nohz ____cacheline_aligned;
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-/**
- * lowest_flag_domain - Return lowest sched_domain containing flag.
- * @cpu: The cpu whose lowest level of sched domain is to
- * be returned.
- * @flag: The flag to check for the lowest sched_domain
- * for the given cpu.
- *
- * Returns the lowest sched_domain of a cpu which contains the given flag.
- */
-static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
-{
- struct sched_domain *sd;
-
- for_each_domain(cpu, sd)
- if (sd->flags & flag)
- break;
-
- return sd;
-}
-
-/**
- * for_each_flag_domain - Iterates over sched_domains containing the flag.
- * @cpu: The cpu whose domains we're iterating over.
- * @sd: variable holding the value of the power_savings_sd
- * for cpu.
- * @flag: The flag to filter the sched_domains to be iterated.
- *
- * Iterates over all the scheduler domains for a given cpu that has the 'flag'
- * set, starting from the lowest sched_domain to the highest.
- */
-#define for_each_flag_domain(cpu, sd, flag) \
- for (sd = lowest_flag_domain(cpu, flag); \
- (sd && (sd->flags & flag)); sd = sd->parent)
-
-/**
- * find_new_ilb - Finds the optimum idle load balancer for nomination.
- * @cpu: The cpu which is nominating a new idle_load_balancer.
- *
- * Returns: Returns the id of the idle load balancer if it exists,
- * Else, returns >= nr_cpu_ids.
- *
- * This algorithm picks the idle load balancer such that it belongs to a
- * semi-idle powersavings sched_domain. The idea is to try and avoid
- * completely idle packages/cores just for the purpose of idle load balancing
- * when there are other idle cpu's which are better suited for that job.
- */
-static int find_new_ilb(int cpu)
+static inline int find_new_ilb(int call_cpu)
{
int ilb = cpumask_first(nohz.idle_cpus_mask);
- struct sched_group *ilbg;
- struct sched_domain *sd;
-
- /*
- * Have idle load balancer selection from semi-idle packages only
- * when power-aware load balancing is enabled
- */
- if (!(sched_smt_power_savings || sched_mc_power_savings))
- goto out_done;
-
- /*
- * Optimize for the case when we have no idle CPUs or only one
- * idle CPU. Don't walk the sched_domain hierarchy in such cases
- */
- if (cpumask_weight(nohz.idle_cpus_mask) < 2)
- goto out_done;
-
- rcu_read_lock();
- for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) {
- ilbg = sd->groups;
-
- do {
- if (ilbg->group_weight !=
- atomic_read(&ilbg->sgp->nr_busy_cpus)) {
- ilb = cpumask_first_and(nohz.idle_cpus_mask,
- sched_group_cpus(ilbg));
- goto unlock;
- }
-
- ilbg = ilbg->next;
-
- } while (ilbg != sd->groups);
- }
-unlock:
- rcu_read_unlock();
-out_done:
if (ilb < nr_cpu_ids && idle_cpu(ilb))
return ilb;
return nr_cpu_ids;
}
-#else /* (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */
-static inline int find_new_ilb(int call_cpu)
-{
- return nr_cpu_ids;
-}
-#endif
/*
* Kick a CPU to do the nohz balancing, if it is time for it. We pick the
@@ -5023,7 +4749,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
raw_spin_lock_irq(&this_rq->lock);
update_rq_clock(this_rq);
- update_cpu_load(this_rq);
+ update_idle_cpu_load(this_rq);
raw_spin_unlock_irq(&this_rq->lock);
rebalance_domains(balance_cpu, CPU_IDLE);
diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c
index 91b4c957f289..b44d604b35d1 100644
--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -4,7 +4,7 @@
* idle-task scheduling class.
*
* (NOTE: these are not related to SCHED_IDLE tasks which are
- * handled in sched_fair.c)
+ * handled in sched/fair.c)
*/
#ifdef CONFIG_SMP
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 44af55e6d5d0..c5565c3c515f 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1803,44 +1803,40 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p)
static void set_cpus_allowed_rt(struct task_struct *p,
const struct cpumask *new_mask)
{
- int weight = cpumask_weight(new_mask);
+ struct rq *rq;
+ int weight;
BUG_ON(!rt_task(p));
- /*
- * Update the migration status of the RQ if we have an RT task
- * which is running AND changing its weight value.
- */
- if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) {
- struct rq *rq = task_rq(p);
-
- if (!task_current(rq, p)) {
- /*
- * Make sure we dequeue this task from the pushable list
- * before going further. It will either remain off of
- * the list because we are no longer pushable, or it
- * will be requeued.
- */
- if (p->rt.nr_cpus_allowed > 1)
- dequeue_pushable_task(rq, p);
+ if (!p->on_rq)
+ return;
- /*
- * Requeue if our weight is changing and still > 1
- */
- if (weight > 1)
- enqueue_pushable_task(rq, p);
+ weight = cpumask_weight(new_mask);
- }
+ /*
+ * Only update if the process changes its state from whether it
+ * can migrate or not.
+ */
+ if ((p->rt.nr_cpus_allowed > 1) == (weight > 1))
+ return;
- if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) {
- rq->rt.rt_nr_migratory++;
- } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) {
- BUG_ON(!rq->rt.rt_nr_migratory);
- rq->rt.rt_nr_migratory--;
- }
+ rq = task_rq(p);
- update_rt_migration(&rq->rt);
+ /*
+ * The process used to be able to migrate OR it can now migrate
+ */
+ if (weight <= 1) {
+ if (!task_current(rq, p))
+ dequeue_pushable_task(rq, p);
+ BUG_ON(!rq->rt.rt_nr_migratory);
+ rq->rt.rt_nr_migratory--;
+ } else {
+ if (!task_current(rq, p))
+ enqueue_pushable_task(rq, p);
+ rq->rt.rt_nr_migratory++;
}
+
+ update_rt_migration(&rq->rt);
}
/* Assumes rq->lock is held */
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index fb3acba4d52e..ba9dccfd24ce 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -201,7 +201,7 @@ struct cfs_bandwidth { };
/* CFS-related fields in a runqueue */
struct cfs_rq {
struct load_weight load;
- unsigned long nr_running, h_nr_running;
+ unsigned int nr_running, h_nr_running;
u64 exec_clock;
u64 min_vruntime;
@@ -279,7 +279,7 @@ static inline int rt_bandwidth_enabled(void)
/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
struct rt_prio_array active;
- unsigned long rt_nr_running;
+ unsigned int rt_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
struct {
int curr; /* highest queued rt task prio */
@@ -353,7 +353,7 @@ struct rq {
* nr_running and cpu_load should be in the same cacheline because
* remote CPUs use both these fields when doing load calculation.
*/
- unsigned long nr_running;
+ unsigned int nr_running;
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
unsigned long last_load_update_tick;
@@ -876,7 +876,7 @@ extern void resched_cpu(int cpu);
extern struct rt_bandwidth def_rt_bandwidth;
extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
-extern void update_cpu_load(struct rq *this_rq);
+extern void update_idle_cpu_load(struct rq *this_rq);
#ifdef CONFIG_CGROUP_CPUACCT
#include <linux/cgroup.h>