#include <linux/slab.h>
#include <linux/profile.h>
#include <linux/interrupt.h>
+#include <linux/random.h>
+#include <linux/mempolicy.h>
+#include <linux/task_work.h>
#include <trace/events/sched.h>
/*
* The idea is to set a period in which each task runs once.
*
- * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
+ * When there are too many tasks (sched_nr_latency) we have to stretch
* this period because otherwise the slices get too small.
*
* p = (nr <= nl) ? l : l*nr/nl
se->exec_start = rq_of(cfs_rq)->clock_task;
}
+/**************************************************
+ * Scheduling class numa methods.
+ *
+ * The purpose of the NUMA bits are to maintain compute (task) and data
+ * (memory) locality. We try and achieve this by making tasks stick to
+ * a particular node (their home node) but if fairness mandates they run
+ * elsewhere for long enough, we let the memory follow them.
+ *
+ * Tasks start out with their home-node unset (-1) this effectively means
+ * they act !NUMA until we've established the task is busy enough to bother
+ * with placement.
+ *
+ * Once we start doing NUMA placement there's two modes, 'small' process-wide
+ * and 'big' per-task. For the small mode we have a process-wide home node
+ * and lazily mirgrate all memory only when this home-node changes.
+ *
+ * For big mode we keep a home-node per task and use periodic fault scans
+ * to try and estalish a task<->page relation. This assumes the task<->page
+ * relation is a compute<->data relation, this is false for things like virt.
+ * and n:m threading solutions but its the best we can do given the
+ * information we have.
+ */
+
+static unsigned long task_h_load(struct task_struct *p);
+
+#ifdef CONFIG_SCHED_NUMA
+static void account_offnode_enqueue(struct rq *rq, struct task_struct *p)
+{
+ p->numa_contrib = task_h_load(p);
+ rq->offnode_weight += p->numa_contrib;
+ rq->offnode_running++;
+}
+
+static void account_offnode_dequeue(struct rq *rq, struct task_struct *p)
+{
+ rq->offnode_weight -= p->numa_contrib;
+ rq->offnode_running--;
+}
+
+/*
+ * numa task sample period in ms: 2.5s
+ */
+unsigned int sysctl_sched_numa_task_period = 2500;
+
+/*
+ * Determine if a process is 'big'.
+ *
+ * Currently only looks at CPU-time used, maybe we should also add an RSS
+ * heuristic.
+ */
+static bool task_numa_big(struct task_struct *p)
+{
+ struct sched_domain *sd;
+ struct task_struct *t;
+ u64 walltime = local_clock();
+ u64 runtime = 0;
+ int weight = 0;
+
+ if (sched_feat(NUMA_FORCE_BIG))
+ return true;
+
+ rcu_read_lock();
+ t = p;
+ do {
+ if (t->sched_class == &fair_sched_class)
+ runtime += t->se.sum_exec_runtime;
+ } while ((t = next_thread(t)) != p);
+
+ sd = rcu_dereference(__raw_get_cpu_var(sd_node));
+ if (sd)
+ weight = sd->span_weight;
+ rcu_read_unlock();
+
+ runtime -= p->numa_runtime_stamp;
+ walltime -= p->numa_walltime_stamp;
+
+ p->numa_runtime_stamp += runtime;
+ p->numa_walltime_stamp += walltime;
+
+ /*
+ * We're 'big' when we burn more than half a node's worth
+ * of cputime.
+ */
+ return runtime > walltime * max(1, weight / 2);
+}
+
+static bool had_many_migrate_failures(struct task_struct *p)
+{
+ /* More than 1/4 of the attempted NUMA page migrations failed. */
+ return p->mm->numa_migrate_failed * 3 > p->mm->numa_migrate_success;
+}
+
+static inline bool need_numa_migration(struct task_struct *p)
+{
+ /*
+ * We need to change our home-node, its been different for 2 samples.
+ * See the whole P(n)^2 story in task_tick_numa().
+ */
+ return p->node_curr == p->node_last && p->node != p->node_curr;
+}
+
+static void sched_setnode_process(struct task_struct *p, int node)
+{
+ struct task_struct *t = p;
+
+ rcu_read_lock();
+ do {
+ sched_setnode(t, node);
+ } while ((t = next_thread(t)) != p);
+ rcu_read_unlock();
+}
+
+/*
+ * The expensive part of numa migration is done from task_work context.
+ * Triggered from task_tick_numa().
+ */
+void task_numa_work(struct callback_head *work)
+{
+ unsigned long migrate, next_scan, now = jiffies;
+ struct task_struct *p = current;
+ bool need_migration;
+ int big;
+
+ WARN_ON_ONCE(p != container_of(work, struct task_struct, rcu));
+
+ /*
+ * Who cares about NUMA placement when they're dying.
+ *
+ * NOTE: make sure not to dereference p->mm before this check,
+ * exit_task_work() happens _after_ exit_mm() so we could be called
+ * without p->mm even though we still had it when we enqueued this
+ * work.
+ */
+ if (p->flags & PF_EXITING)
+ return;
+
+ big = p->mm->numa_big;
+ need_migration = need_numa_migration(p);
+
+ /*
+ * Change per-task state before the process wide freq. throttle,
+ * otherwise it might be a long while ere this task wins the
+ * lottery and gets its home-node set.
+ */
+ if (big && need_migration)
+ sched_setnode(p, p->node_curr);
+
+ /*
+ * Enforce maximal scan/migration frequency..
+ */
+ migrate = p->mm->numa_next_scan;
+ if (time_before(now, migrate))
+ return;
+
+ next_scan = now + 2*msecs_to_jiffies(sysctl_sched_numa_task_period);
+ if (cmpxchg(&p->mm->numa_next_scan, migrate, next_scan) != migrate)
+ return;
+
+ if (!big) {
+ /* Age the numa migrate statistics. */
+ p->mm->numa_migrate_failed /= 2;
+ p->mm->numa_migrate_success /= 2;
+
+ big = p->mm->numa_big = task_numa_big(p);
+ }
+
+ if (need_migration) {
+ if (big)
+ sched_setnode(p, p->node_curr);
+ else
+ sched_setnode_process(p, p->node_curr);
+ }
+
+ if (big || need_migration || had_many_migrate_failures(p))
+ lazy_migrate_process(p->mm);
+}
+
+/*
+ * Sample task location from hardirq context (tick), this has minimal bias with
+ * obvious exceptions of frequency interference and tick avoidance techniques.
+ * If this were to become a problem we could move this sampling into the
+ * sleep/wakeup path -- but we'd prefer to avoid that for obvious reasons.
+ */
+void task_tick_numa(struct rq *rq, struct task_struct *curr)
+{
+ u64 period, now;
+
+ /*
+ * We don't care about NUMA placement if we don't have memory.
+ */
+ if (!curr->mm)
+ return;
+
+ /*
+ * Sample our node location every @sysctl_sched_numa_task_period
+ * runtime ms. We use a two stage selection in order to filter
+ * unlikely locations.
+ *
+ * If P(n) is the probability we're on node 'n', then the probability
+ * we sample the same node twice is P(n)^2. This quadric squishes small
+ * values and makes it more likely we end up on nodes where we have
+ * significant presence.
+ *
+ * Using runtime rather than walltime has the dual advantage that
+ * we (mostly) drive the selection from busy threads and that the
+ * task needs to have done some actual work before we bother with
+ * NUMA placement.
+ */
+ now = curr->se.sum_exec_runtime;
+ period = (u64)sysctl_sched_numa_task_period * NSEC_PER_MSEC;
+
+ if (now - curr->node_stamp > period) {
+ curr->node_stamp = now;
+
+ curr->node_last = curr->node_curr;
+ curr->node_curr = numa_node_id();
+
+ /*
+ * We need to do expensive work to either migrate or
+ * drive priodic state update or scanning for 'big' processes.
+ */
+ if (need_numa_migration(curr) ||
+ !time_before(jiffies, curr->mm->numa_next_scan)) {
+ /*
+ * We can re-use curr->rcu because we checked curr->mm
+ * != NULL so release_task()->call_rcu() was not called
+ * yet and exit_task_work() is called before
+ * exit_notify().
+ */
+ init_task_work(&curr->rcu, task_numa_work);
+ task_work_add(curr, &curr->rcu, true);
+ }
+ }
+}
+#else
+static void account_offnode_enqueue(struct rq *rq, struct task_struct *p)
+{
+}
+
+static void account_offnode_dequeue(struct rq *rq, struct task_struct *p)
+{
+}
+
+static void task_tick_numa(struct rq *rq, struct task_struct *curr)
+{
+}
+#endif /* CONFIG_SCHED_NUMA */
+
/**************************************************
* Scheduling class queueing methods:
*/
if (!parent_entity(se))
update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
#ifdef CONFIG_SMP
- if (entity_is_task(se))
- list_add(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
-#endif
+ if (entity_is_task(se)) {
+ struct rq *rq = rq_of(cfs_rq);
+ struct task_struct *p = task_of(se);
+ struct list_head *tasks = &rq->cfs_tasks;
+
+ if (offnode_task(p)) {
+ account_offnode_enqueue(rq, p);
+ tasks = offnode_tasks(rq);
+ }
+
+ list_add(&se->group_node, tasks);
+ }
+#endif /* CONFIG_SMP */
cfs_rq->nr_running++;
}
update_load_sub(&cfs_rq->load, se->load.weight);
if (!parent_entity(se))
update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
- if (entity_is_task(se))
+ if (entity_is_task(se)) {
+ struct task_struct *p = task_of(se);
+
list_del_init(&se->group_node);
+
+ if (offnode_task(p))
+ account_offnode_dequeue(rq_of(cfs_rq), p);
+ }
cfs_rq->nr_running--;
}
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
struct sched_domain *sd;
+ struct sched_group *sg;
+ int i;
/*
* If the task is going to be woken-up on this cpu and if it is
return prev_cpu;
/*
- * Otherwise, check assigned siblings to find an elegible idle cpu.
+ * Otherwise, iterate the domains and find an elegible idle cpu.
*/
sd = rcu_dereference(per_cpu(sd_llc, target));
-
for_each_lower_domain(sd) {
- if (!cpumask_test_cpu(sd->idle_buddy, tsk_cpus_allowed(p)))
- continue;
- if (idle_cpu(sd->idle_buddy))
- return sd->idle_buddy;
- }
+ sg = sd->groups;
+ do {
+ if (!cpumask_intersects(sched_group_cpus(sg),
+ tsk_cpus_allowed(p)))
+ goto next;
+
+ for_each_cpu(i, sched_group_cpus(sg)) {
+ if (!idle_cpu(i))
+ goto next;
+ }
+ target = cpumask_first_and(sched_group_cpus(sg),
+ tsk_cpus_allowed(p));
+ goto done;
+next:
+ sg = sg->next;
+ } while (sg != sd->groups);
+ }
+done:
return target;
}
+#ifdef CONFIG_SCHED_NUMA
+static inline bool pick_numa_rand(int n)
+{
+ return !(get_random_int() % n);
+}
+
+/*
+ * Pick a random elegible CPU in the target node, hopefully faster
+ * than doing a least-loaded scan.
+ */
+static int numa_select_node_cpu(struct task_struct *p, int node)
+{
+ int weight = cpumask_weight(cpumask_of_node(node));
+ int i, cpu = -1;
+
+ for_each_cpu_and(i, cpumask_of_node(node), tsk_cpus_allowed(p)) {
+ if (cpu < 0 || pick_numa_rand(weight))
+ cpu = i;
+ }
+
+ return cpu;
+}
+#else
+static int numa_select_node_cpu(struct task_struct *p, int node)
+{
+ return -1;
+}
+#endif /* CONFIG_SCHED_NUMA */
+
/*
* sched_balance_self: balance the current task (running on cpu) in domains
* that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
int prev_cpu = task_cpu(p);
int new_cpu = cpu;
int want_affine = 0;
- int want_sd = 1;
int sync = wake_flags & WF_SYNC;
+ int node = tsk_home_node(p);
if (p->nr_cpus_allowed == 1)
return prev_cpu;
}
rcu_read_lock();
- for_each_domain(cpu, tmp) {
- if (!(tmp->flags & SD_LOAD_BALANCE))
- continue;
-
+ if (sched_feat_numa(NUMA_TTWU_BIAS) && node != -1) {
/*
- * If power savings logic is enabled for a domain, see if we
- * are not overloaded, if so, don't balance wider.
+ * For fork,exec find the idlest cpu in the home-node.
*/
- if (tmp->flags & (SD_PREFER_LOCAL)) {
- unsigned long power = 0;
- unsigned long nr_running = 0;
- unsigned long capacity;
- int i;
-
- for_each_cpu(i, sched_domain_span(tmp)) {
- power += power_of(i);
- nr_running += cpu_rq(i)->cfs.nr_running;
- }
+ if (sd_flag & (SD_BALANCE_FORK|SD_BALANCE_EXEC)) {
+ int node_cpu = numa_select_node_cpu(p, node);
+ if (node_cpu < 0)
+ goto find_sd;
+
+ new_cpu = cpu = node_cpu;
+ sd = per_cpu(sd_node, cpu);
+ goto pick_idlest;
+ }
- capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
+ /*
+ * For wake, pretend we were running in the home-node.
+ */
+ if (cpu_to_node(prev_cpu) != node) {
+ int node_cpu = numa_select_node_cpu(p, node);
+ if (node_cpu < 0)
+ goto find_sd;
- if (nr_running < capacity)
- want_sd = 0;
+ if (sched_feat_numa(NUMA_TTWU_TO))
+ cpu = node_cpu;
+ else
+ prev_cpu = node_cpu;
}
+ }
+
+find_sd:
+ for_each_domain(cpu, tmp) {
+ if (!(tmp->flags & SD_LOAD_BALANCE))
+ continue;
/*
* If both cpu and prev_cpu are part of this domain,
if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
affine_sd = tmp;
- want_affine = 0;
- }
-
- if (!want_sd && !want_affine)
break;
+ }
- if (!(tmp->flags & sd_flag))
- continue;
-
- if (want_sd)
+ if (tmp->flags & sd_flag)
sd = tmp;
}
if (affine_sd) {
- if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+ if (cpu != prev_cpu && wake_affine(affine_sd, p, sync))
prev_cpu = cpu;
new_cpu = select_idle_sibling(p, prev_cpu);
goto unlock;
}
+pick_idlest:
while (sd) {
int load_idx = sd->forkexec_idx;
struct sched_group *group;
unsigned int flags;
+ struct list_head *tasks;
+
unsigned int loop;
unsigned int loop_break;
unsigned int loop_max;
+
+ struct rq * (*find_busiest_queue)(struct lb_env *,
+ struct sched_group *);
};
/*
check_preempt_curr(env->dst_rq, p, 0);
}
+static int task_numa_hot(struct task_struct *p, int from_cpu, int to_cpu)
+{
+ int from_dist, to_dist;
+ int node = tsk_home_node(p);
+
+ if (!sched_feat_numa(NUMA_HOT) || node == -1)
+ return 0; /* no node preference */
+
+ from_dist = node_distance(cpu_to_node(from_cpu), node);
+ to_dist = node_distance(cpu_to_node(to_cpu), node);
+
+ if (to_dist < from_dist)
+ return 0; /* getting closer is ok */
+
+ return 1; /* stick to where we are */
+}
+
/*
* Is this task likely cache-hot:
*/
*/
tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd);
+ tsk_cache_hot |= task_numa_hot(p, env->src_cpu, env->dst_cpu);
if (!tsk_cache_hot ||
env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
*
* Called with both runqueues locked.
*/
-static int move_one_task(struct lb_env *env)
+static int __move_one_task(struct lb_env *env)
{
struct task_struct *p, *n;
- list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
+ list_for_each_entry_safe(p, n, env->tasks, se.group_node) {
if (throttled_lb_pair(task_group(p), env->src_rq->cpu, env->dst_cpu))
continue;
return 0;
}
-static unsigned long task_h_load(struct task_struct *p);
+static int move_one_task(struct lb_env *env)
+{
+ if (sched_feat_numa(NUMA_PULL)) {
+ env->tasks = offnode_tasks(env->src_rq);
+ if (__move_one_task(env))
+ return 1;
+ }
+
+ env->tasks = &env->src_rq->cfs_tasks;
+ if (__move_one_task(env))
+ return 1;
+
+ return 0;
+}
static const unsigned int sched_nr_migrate_break = 32;
*/
static int move_tasks(struct lb_env *env)
{
- struct list_head *tasks = &env->src_rq->cfs_tasks;
struct task_struct *p;
unsigned long load;
int pulled = 0;
if (env->imbalance <= 0)
return 0;
- while (!list_empty(tasks)) {
- p = list_first_entry(tasks, struct task_struct, se.group_node);
+again:
+ while (!list_empty(env->tasks)) {
+ p = list_first_entry(env->tasks, struct task_struct, se.group_node);
env->loop++;
/* We've more or less seen every task there is, call it quits */
if (env->loop > env->loop_break) {
env->loop_break += sched_nr_migrate_break;
env->flags |= LBF_NEED_BREAK;
- break;
+ goto out;
}
if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
* the critical section.
*/
if (env->idle == CPU_NEWLY_IDLE)
- break;
+ goto out;
#endif
/*
* weighted load.
*/
if (env->imbalance <= 0)
- break;
+ goto out;
continue;
next:
- list_move_tail(&p->se.group_node, tasks);
+ list_move_tail(&p->se.group_node, env->tasks);
}
+ if (env->tasks == offnode_tasks(env->src_rq)) {
+ env->tasks = &env->src_rq->cfs_tasks;
+ env->loop = 0;
+ goto again;
+ }
+
+out:
/*
* Right now, this is one of only two places move_task() is called,
* so we can safely collect move_task() stats here rather than
unsigned int busiest_group_weight;
int group_imb; /* Is there imbalance in this sd */
+#ifdef CONFIG_SCHED_NUMA
+ struct sched_group *numa_group; /* group which has offnode_tasks */
+ unsigned long numa_group_weight;
+ unsigned long numa_group_running;
+#endif
};
/*
unsigned long group_weight;
int group_imb; /* Is there an imbalance in the group ? */
int group_has_capacity; /* Is there extra capacity in the group? */
+#ifdef CONFIG_SCHED_NUMA
+ unsigned long numa_weight;
+ unsigned long numa_running;
+#endif
};
/**
return load_idx;
}
+#ifdef CONFIG_SCHED_NUMA
+static inline void update_sg_numa_stats(struct sg_lb_stats *sgs, struct rq *rq)
+{
+ sgs->numa_weight += rq->offnode_weight;
+ sgs->numa_running += rq->offnode_running;
+}
+
+/*
+ * Since the offnode lists are indiscriminate (they contain tasks for all other
+ * nodes) it is impossible to say if there's any task on there that wants to
+ * move towards the pulling cpu. Therefore select a random offnode list to pull
+ * from such that eventually we'll try them all.
+ *
+ * Select a random group that has offnode tasks as sds->numa_group
+ */
+static inline void update_sd_numa_stats(struct sched_domain *sd,
+ struct sched_group *group, struct sd_lb_stats *sds,
+ int local_group, struct sg_lb_stats *sgs)
+{
+ if (!(sd->flags & SD_NUMA))
+ return;
+
+ if (local_group)
+ return;
+
+ if (!sgs->numa_running)
+ return;
+
+ if (!sds->numa_group || pick_numa_rand(sd->span_weight / group->group_weight)) {
+ sds->numa_group = group;
+ sds->numa_group_weight = sgs->numa_weight;
+ sds->numa_group_running = sgs->numa_running;
+ }
+}
+
+/*
+ * Pick a random queue from the group that has offnode tasks.
+ */
+static struct rq *find_busiest_numa_queue(struct lb_env *env,
+ struct sched_group *group)
+{
+ struct rq *busiest = NULL, *rq;
+ int cpu;
+
+ for_each_cpu_and(cpu, sched_group_cpus(group), env->cpus) {
+ rq = cpu_rq(cpu);
+ if (!rq->offnode_running)
+ continue;
+ if (!busiest || pick_numa_rand(group->group_weight))
+ busiest = rq;
+ }
+
+ return busiest;
+}
+
+/*
+ * Called in case of no other imbalance, if there is a queue running offnode
+ * tasksk we'll say we're imbalanced anyway to nudge these tasks towards their
+ * proper node.
+ */
+static inline int check_numa_busiest_group(struct lb_env *env, struct sd_lb_stats *sds)
+{
+ if (!sched_feat(NUMA_PULL_BIAS))
+ return 0;
+
+ if (!sds->numa_group)
+ return 0;
+
+ env->imbalance = sds->numa_group_weight / sds->numa_group_running;
+ sds->busiest = sds->numa_group;
+ env->find_busiest_queue = find_busiest_numa_queue;
+ return 1;
+}
+
+static inline bool need_active_numa_balance(struct lb_env *env)
+{
+ return env->find_busiest_queue == find_busiest_numa_queue &&
+ env->src_rq->offnode_running == 1 &&
+ env->src_rq->nr_running == 1;
+}
+
+#else /* CONFIG_SCHED_NUMA */
+
+static inline void update_sg_numa_stats(struct sg_lb_stats *sgs, struct rq *rq)
+{
+}
+
+static inline void update_sd_numa_stats(struct sched_domain *sd,
+ struct sched_group *group, struct sd_lb_stats *sds,
+ int local_group, struct sg_lb_stats *sgs)
+{
+}
+
+static inline int check_numa_busiest_group(struct lb_env *env, struct sd_lb_stats *sds)
+{
+ return 0;
+}
+
+static inline bool need_active_numa_balance(struct lb_env *env)
+{
+ return false;
+}
+#endif /* CONFIG_SCHED_NUMA */
+
unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
{
return SCHED_POWER_SCALE;
sgs->sum_weighted_load += weighted_cpuload(i);
if (idle_cpu(i))
sgs->idle_cpus++;
+
+ update_sg_numa_stats(sgs, rq);
}
/*
sds->group_imb = sgs.group_imb;
}
+ update_sd_numa_stats(env->sd, sg, sds, local_group, &sgs);
+
sg = sg->next;
} while (sg != env->sd->groups);
}
return sds.busiest;
out_balanced:
+ if (check_numa_busiest_group(env, &sds))
+ return sds.busiest;
+
ret:
env->imbalance = 0;
return NULL;
return 1;
}
+ if (need_active_numa_balance(env))
+ return 1;
+
return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
}
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
struct lb_env env = {
- .sd = sd,
- .dst_cpu = this_cpu,
- .dst_rq = this_rq,
- .dst_grpmask = sched_group_cpus(sd->groups),
- .idle = idle,
- .loop_break = sched_nr_migrate_break,
- .cpus = cpus,
+ .sd = sd,
+ .dst_cpu = this_cpu,
+ .dst_rq = this_rq,
+ .dst_grpmask = sched_group_cpus(sd->groups),
+ .idle = idle,
+ .loop_break = sched_nr_migrate_break,
+ .cpus = cpus,
+ .find_busiest_queue = find_busiest_queue,
};
cpumask_copy(cpus, cpu_active_mask);
goto out_balanced;
}
- busiest = find_busiest_queue(&env, group);
+ busiest = env.find_busiest_queue(&env, group);
if (!busiest) {
schedstat_inc(sd, lb_nobusyq[idle]);
goto out_balanced;
}
+ env.src_rq = busiest;
+ env.src_cpu = busiest->cpu;
- BUG_ON(busiest == this_rq);
+ BUG_ON(busiest == env.dst_rq);
schedstat_add(sd, lb_imbalance[idle], env.imbalance);
env.src_cpu = busiest->cpu;
env.src_rq = busiest;
env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
+ if (sched_feat_numa(NUMA_PULL))
+ env.tasks = offnode_tasks(busiest);
+ else
+ env.tasks = &busiest->cfs_tasks;
update_h_load(env.src_cpu);
more_balance:
local_irq_save(flags);
- double_rq_lock(this_rq, busiest);
+ double_rq_lock(env.dst_rq, busiest);
/*
* cur_ld_moved - load moved in current iteration
*/
cur_ld_moved = move_tasks(&env);
ld_moved += cur_ld_moved;
- double_rq_unlock(this_rq, busiest);
+ double_rq_unlock(env.dst_rq, busiest);
local_irq_restore(flags);
if (env.flags & LBF_NEED_BREAK) {
if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0 &&
lb_iterations++ < max_lb_iterations) {
- this_rq = cpu_rq(env.new_dst_cpu);
- env.dst_rq = this_rq;
+ env.dst_rq = cpu_rq(env.new_dst_cpu);
env.dst_cpu = env.new_dst_cpu;
env.flags &= ~LBF_SOME_PINNED;
env.loop = 0;
return;
}
-static inline void clear_nohz_tick_stopped(int cpu)
+static inline void nohz_balance_exit_idle(int cpu)
{
if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
}
/*
- * This routine will record that this cpu is going idle with tick stopped.
+ * This routine will record that the cpu is going idle with tick stopped.
* This info will be used in performing idle load balancing in the future.
*/
-void select_nohz_load_balancer(int stop_tick)
+void nohz_balance_enter_idle(int cpu)
{
- int cpu = smp_processor_id();
-
/*
* If this cpu is going down, then nothing needs to be done.
*/
if (!cpu_active(cpu))
return;
- if (stop_tick) {
- if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
- return;
+ if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
+ return;
- cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
- atomic_inc(&nohz.nr_cpus);
- set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
- }
- return;
+ cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
+ atomic_inc(&nohz.nr_cpus);
+ set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
}
static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
{
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DYING:
- clear_nohz_tick_stopped(smp_processor_id());
+ nohz_balance_exit_idle(smp_processor_id());
return NOTIFY_OK;
default:
return NOTIFY_DONE;
if (need_resched())
break;
- raw_spin_lock_irq(&this_rq->lock);
- update_rq_clock(this_rq);
- update_idle_cpu_load(this_rq);
- raw_spin_unlock_irq(&this_rq->lock);
+ rq = cpu_rq(balance_cpu);
+
+ raw_spin_lock_irq(&rq->lock);
+ update_rq_clock(rq);
+ update_idle_cpu_load(rq);
+ raw_spin_unlock_irq(&rq->lock);
rebalance_domains(balance_cpu, CPU_IDLE);
- rq = cpu_rq(balance_cpu);
if (time_after(this_rq->next_balance, rq->next_balance))
this_rq->next_balance = rq->next_balance;
}
* busy tick after returning from idle, we will update the busy stats.
*/
set_cpu_sd_state_busy();
- clear_nohz_tick_stopped(cpu);
+ nohz_balance_exit_idle(cpu);
/*
* None are in tickless mode and hence no need for NOHZ idle load
cfs_rq = cfs_rq_of(se);
entity_tick(cfs_rq, se, queued);
}
+
+ if (sched_feat_numa(NUMA))
+ task_tick_numa(rq, curr);
}
/*
projects / karo-tx-linux.git / blobdiff