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-rw-r--r--kernel/sched/fair.c1453
1 files changed, 1038 insertions, 415 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3b6038225c17..fc270d4fbd73 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -50,7 +50,6 @@
unsigned int sysctl_sched_latency = 6000000ULL;
unsigned int normalized_sysctl_sched_latency = 6000000ULL;
-unsigned int sysctl_sched_is_big_little = 0;
unsigned int sysctl_sched_sync_hint_enable = 1;
unsigned int sysctl_sched_initial_task_util = 0;
unsigned int sysctl_sched_cstate_aware = 1;
@@ -119,6 +118,12 @@ unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL;
unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
#endif
+/*
+ * The margin used when comparing utilization with CPU capacity:
+ * util * margin < capacity * 1024
+ */
+unsigned int capacity_margin = 1280; /* ~20% */
+
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
lw->weight += inc;
@@ -294,19 +299,59 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
if (!cfs_rq->on_list) {
+ struct rq *rq = rq_of(cfs_rq);
+ int cpu = cpu_of(rq);
/*
* Ensure we either appear before our parent (if already
* enqueued) or force our parent to appear after us when it is
- * enqueued. The fact that we always enqueue bottom-up
- * reduces this to two cases.
+ * enqueued. The fact that we always enqueue bottom-up
+ * reduces this to two cases and a special case for the root
+ * cfs_rq. Furthermore, it also means that we will always reset
+ * tmp_alone_branch either when the branch is connected
+ * to a tree or when we reach the beg of the tree
*/
if (cfs_rq->tg->parent &&
- cfs_rq->tg->parent->cfs_rq[cpu_of(rq_of(cfs_rq))]->on_list) {
- list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
- &rq_of(cfs_rq)->leaf_cfs_rq_list);
- } else {
+ cfs_rq->tg->parent->cfs_rq[cpu]->on_list) {
+ /*
+ * If parent is already on the list, we add the child
+ * just before. Thanks to circular linked property of
+ * the list, this means to put the child at the tail
+ * of the list that starts by parent.
+ */
+ list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
+ &(cfs_rq->tg->parent->cfs_rq[cpu]->leaf_cfs_rq_list));
+ /*
+ * The branch is now connected to its tree so we can
+ * reset tmp_alone_branch to the beginning of the
+ * list.
+ */
+ rq->tmp_alone_branch = &rq->leaf_cfs_rq_list;
+ } else if (!cfs_rq->tg->parent) {
+ /*
+ * cfs rq without parent should be put
+ * at the tail of the list.
+ */
list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
- &rq_of(cfs_rq)->leaf_cfs_rq_list);
+ &rq->leaf_cfs_rq_list);
+ /*
+ * We have reach the beg of a tree so we can reset
+ * tmp_alone_branch to the beginning of the list.
+ */
+ rq->tmp_alone_branch = &rq->leaf_cfs_rq_list;
+ } else {
+ /*
+ * The parent has not already been added so we want to
+ * make sure that it will be put after us.
+ * tmp_alone_branch points to the beg of the branch
+ * where we will add parent.
+ */
+ list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
+ rq->tmp_alone_branch);
+ /*
+ * update tmp_alone_branch to points to the new beg
+ * of the branch
+ */
+ rq->tmp_alone_branch = &cfs_rq->leaf_cfs_rq_list;
}
cfs_rq->on_list = 1;
@@ -664,7 +709,7 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
}
#ifdef CONFIG_SMP
-static int select_idle_sibling(struct task_struct *p, int cpu);
+static int select_idle_sibling(struct task_struct *p, int prev_cpu, int cpu);
static unsigned long task_h_load(struct task_struct *p);
/*
@@ -688,20 +733,115 @@ void init_entity_runnable_average(struct sched_entity *se)
* will definitely be update (after enqueue).
*/
sa->period_contrib = 1023;
- sa->load_avg = scale_load_down(se->load.weight);
+ /*
+ * Tasks are intialized with full load to be seen as heavy tasks until
+ * they get a chance to stabilize to their real load level.
+ * Group entities are intialized with zero load to reflect the fact that
+ * nothing has been attached to the task group yet.
+ */
+ if (entity_is_task(se))
+ sa->load_avg = scale_load_down(se->load.weight);
sa->load_sum = sa->load_avg * LOAD_AVG_MAX;
- sa->util_avg = sched_freq() ?
- sysctl_sched_initial_task_util :
- scale_load_down(SCHED_LOAD_SCALE);
- sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
+ /*
+ * In previous Android versions, we used to have:
+ * sa->util_avg = sched_freq() ?
+ * sysctl_sched_initial_task_util :
+ * scale_load_down(SCHED_LOAD_SCALE);
+ * sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
+ * However, that functionality has been moved to enqueue.
+ * It is unclear if we should restore this in enqueue.
+ */
+ /*
+ * At this point, util_avg won't be used in select_task_rq_fair anyway
+ */
+ sa->util_avg = 0;
+ sa->util_sum = 0;
/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
}
+static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq);
+static void attach_entity_cfs_rq(struct sched_entity *se);
+
+/*
+ * With new tasks being created, their initial util_avgs are extrapolated
+ * based on the cfs_rq's current util_avg:
+ *
+ * util_avg = cfs_rq->util_avg / (cfs_rq->load_avg + 1) * se.load.weight
+ *
+ * However, in many cases, the above util_avg does not give a desired
+ * value. Moreover, the sum of the util_avgs may be divergent, such
+ * as when the series is a harmonic series.
+ *
+ * To solve this problem, we also cap the util_avg of successive tasks to
+ * only 1/2 of the left utilization budget:
+ *
+ * util_avg_cap = (1024 - cfs_rq->avg.util_avg) / 2^n
+ *
+ * where n denotes the nth task.
+ *
+ * For example, a simplest series from the beginning would be like:
+ *
+ * task util_avg: 512, 256, 128, 64, 32, 16, 8, ...
+ * cfs_rq util_avg: 512, 768, 896, 960, 992, 1008, 1016, ...
+ *
+ * Finally, that extrapolated util_avg is clamped to the cap (util_avg_cap)
+ * if util_avg > util_avg_cap.
+ */
+void post_init_entity_util_avg(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ struct sched_avg *sa = &se->avg;
+ long cap = (long)(SCHED_CAPACITY_SCALE - cfs_rq->avg.util_avg) / 2;
+
+ if (cap > 0) {
+ if (cfs_rq->avg.util_avg != 0) {
+ sa->util_avg = cfs_rq->avg.util_avg * se->load.weight;
+ sa->util_avg /= (cfs_rq->avg.load_avg + 1);
+
+ if (sa->util_avg > cap)
+ sa->util_avg = cap;
+ } else {
+ sa->util_avg = cap;
+ }
+ /*
+ * If we wish to restore tuning via setting initial util,
+ * this is where we should do it.
+ */
+ sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
+ }
+
+ if (entity_is_task(se)) {
+ struct task_struct *p = task_of(se);
+ if (p->sched_class != &fair_sched_class) {
+ /*
+ * For !fair tasks do:
+ *
+ update_cfs_rq_load_avg(now, cfs_rq, false);
+ attach_entity_load_avg(cfs_rq, se);
+ switched_from_fair(rq, p);
+ *
+ * such that the next switched_to_fair() has the
+ * expected state.
+ */
+ se->avg.last_update_time = cfs_rq_clock_task(cfs_rq);
+ return;
+ }
+ }
+
+ attach_entity_cfs_rq(se);
+}
+
#else
void init_entity_runnable_average(struct sched_entity *se)
{
}
-#endif
+void post_init_entity_util_avg(struct sched_entity *se)
+{
+}
+static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
+{
+}
+#endif /* CONFIG_SMP */
/*
* Update the current task's runtime statistics.
@@ -1425,7 +1565,8 @@ balance:
* Call select_idle_sibling to maybe find a better one.
*/
if (!cur)
- env->dst_cpu = select_idle_sibling(env->p, env->dst_cpu);
+ env->dst_cpu = select_idle_sibling(env->p, env->src_cpu,
+ env->dst_cpu);
assign:
assigned = true;
@@ -2410,28 +2551,22 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
#ifdef CONFIG_FAIR_GROUP_SCHED
# ifdef CONFIG_SMP
-static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
+static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
{
- long tg_weight;
+ long tg_weight, load, shares;
/*
- * Use this CPU's real-time load instead of the last load contribution
- * as the updating of the contribution is delayed, and we will use the
- * the real-time load to calc the share. See update_tg_load_avg().
+ * This really should be: cfs_rq->avg.load_avg, but instead we use
+ * cfs_rq->load.weight, which is its upper bound. This helps ramp up
+ * the shares for small weight interactive tasks.
*/
- tg_weight = atomic_long_read(&tg->load_avg);
- tg_weight -= cfs_rq->tg_load_avg_contrib;
- tg_weight += cfs_rq->load.weight;
+ load = scale_load_down(cfs_rq->load.weight);
- return tg_weight;
-}
-
-static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
-{
- long tg_weight, load, shares;
+ tg_weight = atomic_long_read(&tg->load_avg);
- tg_weight = calc_tg_weight(tg, cfs_rq);
- load = cfs_rq->load.weight;
+ /* Ensure tg_weight >= load */
+ tg_weight -= cfs_rq->tg_load_avg_contrib;
+ tg_weight += load;
shares = (tg->shares * load);
if (tg_weight)
@@ -2450,6 +2585,7 @@ static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
return tg->shares;
}
# endif /* CONFIG_SMP */
+
static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
unsigned long weight)
{
@@ -2468,16 +2604,20 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
-static void update_cfs_shares(struct cfs_rq *cfs_rq)
+static void update_cfs_shares(struct sched_entity *se)
{
+ struct cfs_rq *cfs_rq = group_cfs_rq(se);
struct task_group *tg;
- struct sched_entity *se;
long shares;
- tg = cfs_rq->tg;
- se = tg->se[cpu_of(rq_of(cfs_rq))];
- if (!se || throttled_hierarchy(cfs_rq))
+ if (!cfs_rq)
+ return;
+
+ if (throttled_hierarchy(cfs_rq))
return;
+
+ tg = cfs_rq->tg;
+
#ifndef CONFIG_SMP
if (likely(se->load.weight == tg->shares))
return;
@@ -2486,8 +2626,9 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq)
reweight_entity(cfs_rq_of(se), se, shares);
}
+
#else /* CONFIG_FAIR_GROUP_SCHED */
-static inline void update_cfs_shares(struct cfs_rq *cfs_rq)
+static inline void update_cfs_shares(struct sched_entity *se)
{
}
#endif /* CONFIG_FAIR_GROUP_SCHED */
@@ -3789,25 +3930,262 @@ __update_load_avg(u64 now, int cpu, struct sched_avg *sa,
return decayed;
}
-#ifdef CONFIG_FAIR_GROUP_SCHED
/*
- * Updating tg's load_avg is necessary before update_cfs_share (which is done)
- * and effective_load (which is not done because it is too costly).
+ * Signed add and clamp on underflow.
+ *
+ * Explicitly do a load-store to ensure the intermediate value never hits
+ * memory. This allows lockless observations without ever seeing the negative
+ * values.
+ */
+#define add_positive(_ptr, _val) do { \
+ typeof(_ptr) ptr = (_ptr); \
+ typeof(_val) val = (_val); \
+ typeof(*ptr) res, var = READ_ONCE(*ptr); \
+ \
+ res = var + val; \
+ \
+ if (val < 0 && res > var) \
+ res = 0; \
+ \
+ WRITE_ONCE(*ptr, res); \
+} while (0)
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+/**
+ * update_tg_load_avg - update the tg's load avg
+ * @cfs_rq: the cfs_rq whose avg changed
+ * @force: update regardless of how small the difference
+ *
+ * This function 'ensures': tg->load_avg := \Sum tg->cfs_rq[]->avg.load.
+ * However, because tg->load_avg is a global value there are performance
+ * considerations.
+ *
+ * In order to avoid having to look at the other cfs_rq's, we use a
+ * differential update where we store the last value we propagated. This in
+ * turn allows skipping updates if the differential is 'small'.
+ *
+ * Updating tg's load_avg is necessary before update_cfs_share() (which is
+ * done) and effective_load() (which is not done because it is too costly).
*/
static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
{
long delta = cfs_rq->avg.load_avg - cfs_rq->tg_load_avg_contrib;
+ /*
+ * No need to update load_avg for root_task_group as it is not used.
+ */
+ if (cfs_rq->tg == &root_task_group)
+ return;
+
if (force || abs(delta) > cfs_rq->tg_load_avg_contrib / 64) {
atomic_long_add(delta, &cfs_rq->tg->load_avg);
cfs_rq->tg_load_avg_contrib = cfs_rq->avg.load_avg;
}
}
+/*
+ * Called within set_task_rq() right before setting a task's cpu. The
+ * caller only guarantees p->pi_lock is held; no other assumptions,
+ * including the state of rq->lock, should be made.
+ */
+void set_task_rq_fair(struct sched_entity *se,
+ struct cfs_rq *prev, struct cfs_rq *next)
+{
+ if (!sched_feat(ATTACH_AGE_LOAD))
+ return;
+
+ /*
+ * We are supposed to update the task to "current" time, then its up to
+ * date and ready to go to new CPU/cfs_rq. But we have difficulty in
+ * getting what current time is, so simply throw away the out-of-date
+ * time. This will result in the wakee task is less decayed, but giving
+ * the wakee more load sounds not bad.
+ */
+ if (se->avg.last_update_time && prev) {
+ u64 p_last_update_time;
+ u64 n_last_update_time;
+
+#ifndef CONFIG_64BIT
+ u64 p_last_update_time_copy;
+ u64 n_last_update_time_copy;
+
+ do {
+ p_last_update_time_copy = prev->load_last_update_time_copy;
+ n_last_update_time_copy = next->load_last_update_time_copy;
+
+ smp_rmb();
+
+ p_last_update_time = prev->avg.last_update_time;
+ n_last_update_time = next->avg.last_update_time;
+
+ } while (p_last_update_time != p_last_update_time_copy ||
+ n_last_update_time != n_last_update_time_copy);
+#else
+ p_last_update_time = prev->avg.last_update_time;
+ n_last_update_time = next->avg.last_update_time;
+#endif
+ __update_load_avg(p_last_update_time, cpu_of(rq_of(prev)),
+ &se->avg, 0, 0, NULL);
+ se->avg.last_update_time = n_last_update_time;
+ }
+}
+
+/* Take into account change of utilization of a child task group */
+static inline void
+update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ struct cfs_rq *gcfs_rq = group_cfs_rq(se);
+ long delta = gcfs_rq->avg.util_avg - se->avg.util_avg;
+
+ /* Nothing to update */
+ if (!delta)
+ return;
+
+ /* Set new sched_entity's utilization */
+ se->avg.util_avg = gcfs_rq->avg.util_avg;
+ se->avg.util_sum = se->avg.util_avg * LOAD_AVG_MAX;
+
+ /* Update parent cfs_rq utilization */
+ add_positive(&cfs_rq->avg.util_avg, delta);
+ cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * LOAD_AVG_MAX;
+}
+
+/* Take into account change of load of a child task group */
+static inline void
+update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ struct cfs_rq *gcfs_rq = group_cfs_rq(se);
+ long delta, load = gcfs_rq->avg.load_avg;
+
+ /*
+ * If the load of group cfs_rq is null, the load of the
+ * sched_entity will also be null so we can skip the formula
+ */
+ if (load) {
+ long tg_load;
+
+ /* Get tg's load and ensure tg_load > 0 */
+ tg_load = atomic_long_read(&gcfs_rq->tg->load_avg) + 1;
+
+ /* Ensure tg_load >= load and updated with current load*/
+ tg_load -= gcfs_rq->tg_load_avg_contrib;
+ tg_load += load;
+
+ /*
+ * We need to compute a correction term in the case that the
+ * task group is consuming more CPU than a task of equal
+ * weight. A task with a weight equals to tg->shares will have
+ * a load less or equal to scale_load_down(tg->shares).
+ * Similarly, the sched_entities that represent the task group
+ * at parent level, can't have a load higher than
+ * scale_load_down(tg->shares). And the Sum of sched_entities'
+ * load must be <= scale_load_down(tg->shares).
+ */
+ if (tg_load > scale_load_down(gcfs_rq->tg->shares)) {
+ /* scale gcfs_rq's load into tg's shares*/
+ load *= scale_load_down(gcfs_rq->tg->shares);
+ load /= tg_load;
+ }
+ }
+
+ delta = load - se->avg.load_avg;
+
+ /* Nothing to update */
+ if (!delta)
+ return;
+
+ /* Set new sched_entity's load */
+ se->avg.load_avg = load;
+ se->avg.load_sum = se->avg.load_avg * LOAD_AVG_MAX;
+
+ /* Update parent cfs_rq load */
+ add_positive(&cfs_rq->avg.load_avg, delta);
+ cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * LOAD_AVG_MAX;
+
+ /*
+ * If the sched_entity is already enqueued, we also have to update the
+ * runnable load avg.
+ */
+ if (se->on_rq) {
+ /* Update parent cfs_rq runnable_load_avg */
+ add_positive(&cfs_rq->runnable_load_avg, delta);
+ cfs_rq->runnable_load_sum = cfs_rq->runnable_load_avg * LOAD_AVG_MAX;
+ }
+}
+
+static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq)
+{
+ cfs_rq->propagate_avg = 1;
+}
+
+static inline int test_and_clear_tg_cfs_propagate(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq = group_cfs_rq(se);
+
+ if (!cfs_rq->propagate_avg)
+ return 0;
+
+ cfs_rq->propagate_avg = 0;
+ return 1;
+}
+
+/* Update task and its cfs_rq load average */
+static inline int propagate_entity_load_avg(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq;
+
+ if (entity_is_task(se))
+ return 0;
+
+ if (!test_and_clear_tg_cfs_propagate(se))
+ return 0;
+
+ cfs_rq = cfs_rq_of(se);
+
+ set_tg_cfs_propagate(cfs_rq);
+
+ update_tg_cfs_util(cfs_rq, se);
+ update_tg_cfs_load(cfs_rq, se);
+
+ return 1;
+}
+
#else /* CONFIG_FAIR_GROUP_SCHED */
+
static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) {}
+
+static inline int propagate_entity_load_avg(struct sched_entity *se)
+{
+ return 0;
+}
+
+static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) {}
+
#endif /* CONFIG_FAIR_GROUP_SCHED */
+static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq)
+{
+ if (&this_rq()->cfs == cfs_rq) {
+ /*
+ * There are a few boundary cases this might miss but it should
+ * get called often enough that that should (hopefully) not be
+ * a real problem -- added to that it only calls on the local
+ * CPU, so if we enqueue remotely we'll miss an update, but
+ * the next tick/schedule should update.
+ *
+ * It will not get called when we go idle, because the idle
+ * thread is a different class (!fair), nor will the utilization
+ * number include things like RT tasks.
+ *
+ * As is, the util number is not freq-invariant (we'd have to
+ * implement arch_scale_freq_capacity() for that).
+ *
+ * See cpu_util().
+ */
+ cpufreq_update_util(rq_of(cfs_rq), 0);
+ }
+}
+
static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq);
/*
@@ -3827,23 +4205,43 @@ static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq);
WRITE_ONCE(*ptr, res); \
} while (0)
-/* Group cfs_rq's load_avg is used for task_h_load and update_cfs_share */
-static inline int update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
+/**
+ * update_cfs_rq_load_avg - update the cfs_rq's load/util averages
+ * @now: current time, as per cfs_rq_clock_task()
+ * @cfs_rq: cfs_rq to update
+ * @update_freq: should we call cfs_rq_util_change() or will the call do so
+ *
+ * The cfs_rq avg is the direct sum of all its entities (blocked and runnable)
+ * avg. The immediate corollary is that all (fair) tasks must be attached, see
+ * post_init_entity_util_avg().
+ *
+ * cfs_rq->avg is used for task_h_load() and update_cfs_share() for example.
+ *
+ * Returns true if the load decayed or we removed load.
+ *
+ * Since both these conditions indicate a changed cfs_rq->avg.load we should
+ * call update_tg_load_avg() when this function returns true.
+ */
+static inline int
+update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
{
struct sched_avg *sa = &cfs_rq->avg;
- int decayed, removed = 0;
+ int decayed, removed = 0, removed_util = 0;
if (atomic_long_read(&cfs_rq->removed_load_avg)) {
s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0);
sub_positive(&sa->load_avg, r);
sub_positive(&sa->load_sum, r * LOAD_AVG_MAX);
removed = 1;
+ set_tg_cfs_propagate(cfs_rq);
}
if (atomic_long_read(&cfs_rq->removed_util_avg)) {
long r = atomic_long_xchg(&cfs_rq->removed_util_avg, 0);
sub_positive(&sa->util_avg, r);
sub_positive(&sa->util_sum, r * LOAD_AVG_MAX);
+ removed_util = 1;
+ set_tg_cfs_propagate(cfs_rq);
}
decayed = __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
@@ -3858,68 +4256,89 @@ static inline int update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
if (cfs_rq == &rq_of(cfs_rq)->cfs)
trace_sched_load_avg_cpu(cpu_of(rq_of(cfs_rq)), cfs_rq);
+ if (update_freq && (decayed || removed_util))
+ cfs_rq_util_change(cfs_rq);
+
return decayed || removed;
}
+/*
+ * Optional action to be done while updating the load average
+ */
+#define UPDATE_TG 0x1
+#define SKIP_AGE_LOAD 0x2
+
/* Update task and its cfs_rq load average */
-static inline void update_load_avg(struct sched_entity *se, int update_tg)
+static inline void update_load_avg(struct sched_entity *se, int flags)
{
struct cfs_rq *cfs_rq = cfs_rq_of(se);
u64 now = cfs_rq_clock_task(cfs_rq);
int cpu = cpu_of(rq_of(cfs_rq));
+ int decayed;
+ void *ptr = NULL;
/*
* Track task load average for carrying it to new CPU after migrated, and
* track group sched_entity load average for task_h_load calc in migration
*/
- __update_load_avg(now, cpu, &se->avg,
+ if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) {
+ __update_load_avg(now, cpu, &se->avg,
se->on_rq * scale_load_down(se->load.weight),
cfs_rq->curr == se, NULL);
+ }
- if (update_cfs_rq_load_avg(now, cfs_rq) && update_tg)
+ decayed = update_cfs_rq_load_avg(now, cfs_rq, true);
+ decayed |= propagate_entity_load_avg(se);
+
+ if (decayed && (flags & UPDATE_TG))
update_tg_load_avg(cfs_rq, 0);
- if (entity_is_task(se))
- trace_sched_load_avg_task(task_of(se), &se->avg);
+ if (entity_is_task(se)) {
+#ifdef CONFIG_SCHED_WALT
+ ptr = (void *)&(task_of(se)->ravg);
+#endif
+ trace_sched_load_avg_task(task_of(se), &se->avg, ptr);
+ }
}
+/**
+ * attach_entity_load_avg - attach this entity to its cfs_rq load avg
+ * @cfs_rq: cfs_rq to attach to
+ * @se: sched_entity to attach
+ *
+ * Must call update_cfs_rq_load_avg() before this, since we rely on
+ * cfs_rq->avg.last_update_time being current.
+ */
static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- if (!sched_feat(ATTACH_AGE_LOAD))
- goto skip_aging;
-
- /*
- * If we got migrated (either between CPUs or between cgroups) we'll
- * have aged the average right before clearing @last_update_time.
- */
- if (se->avg.last_update_time) {
- __update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)),
- &se->avg, 0, 0, NULL);
-
- /*
- * XXX: we could have just aged the entire load away if we've been
- * absent from the fair class for too long.
- */
- }
-
-skip_aging:
se->avg.last_update_time = cfs_rq->avg.last_update_time;
cfs_rq->avg.load_avg += se->avg.load_avg;
cfs_rq->avg.load_sum += se->avg.load_sum;
cfs_rq->avg.util_avg += se->avg.util_avg;
cfs_rq->avg.util_sum += se->avg.util_sum;
+ set_tg_cfs_propagate(cfs_rq);
+
+ cfs_rq_util_change(cfs_rq);
}
+/**
+ * detach_entity_load_avg - detach this entity from its cfs_rq load avg
+ * @cfs_rq: cfs_rq to detach from
+ * @se: sched_entity to detach
+ *
+ * Must call update_cfs_rq_load_avg() before this, since we rely on
+ * cfs_rq->avg.last_update_time being current.
+ */
static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- __update_load_avg(cfs_rq->avg.last_update_time, cpu_of(rq_of(cfs_rq)),
- &se->avg, se->on_rq * scale_load_down(se->load.weight),
- cfs_rq->curr == se, NULL);
sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg);
sub_positive(&cfs_rq->avg.load_sum, se->avg.load_sum);
sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg);
sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum);
+ set_tg_cfs_propagate(cfs_rq);
+
+ cfs_rq_util_change(cfs_rq);
}
/* Add the load generated by se into cfs_rq's load average */
@@ -3927,34 +4346,20 @@ static inline void
enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
struct sched_avg *sa = &se->avg;
- u64 now = cfs_rq_clock_task(cfs_rq);
- int migrated, decayed;
-
- migrated = !sa->last_update_time;
- if (!migrated) {
- __update_load_avg(now, cpu_of(rq_of(cfs_rq)), sa,
- se->on_rq * scale_load_down(se->load.weight),
- cfs_rq->curr == se, NULL);
- }
-
- decayed = update_cfs_rq_load_avg(now, cfs_rq);
cfs_rq->runnable_load_avg += sa->load_avg;
cfs_rq->runnable_load_sum += sa->load_sum;
- if (migrated)
+ if (!sa->last_update_time) {
attach_entity_load_avg(cfs_rq, se);
-
- if (decayed || migrated)
update_tg_load_avg(cfs_rq, 0);
+ }
}
/* Remove the runnable load generated by se from cfs_rq's runnable load average */
static inline void
dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- update_load_avg(se, 1);
-
cfs_rq->runnable_load_avg =
max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0);
cfs_rq->runnable_load_sum =
@@ -3983,13 +4388,25 @@ static inline u64 cfs_rq_last_update_time(struct cfs_rq *cfs_rq)
#endif
/*
+ * Synchronize entity load avg of dequeued entity without locking
+ * the previous rq.
+ */
+void sync_entity_load_avg(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+ u64 last_update_time;
+
+ last_update_time = cfs_rq_last_update_time(cfs_rq);
+ __update_load_avg(last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, 0, 0, NULL);
+}
+
+/*
* Task first catches up with cfs_rq, and then subtract
* itself from the cfs_rq (task must be off the queue now).
*/
void remove_entity_load_avg(struct sched_entity *se)
{
struct cfs_rq *cfs_rq = cfs_rq_of(se);
- u64 last_update_time;
/*
* Newly created task or never used group entity should not be removed
@@ -3998,9 +4415,7 @@ void remove_entity_load_avg(struct sched_entity *se)
if (se->avg.last_update_time == 0)
return;
- last_update_time = cfs_rq_last_update_time(cfs_rq);
-
- __update_load_avg(last_update_time, cpu_of(rq_of(cfs_rq)), &se->avg, 0, 0, NULL);
+ sync_entity_load_avg(se);
atomic_long_add(se->avg.load_avg, &cfs_rq->removed_load_avg);
atomic_long_add(se->avg.util_avg, &cfs_rq->removed_util_avg);
}
@@ -4037,7 +4452,16 @@ static int idle_balance(struct rq *this_rq);
#else /* CONFIG_SMP */
-static inline void update_load_avg(struct sched_entity *se, int update_tg) {}
+static inline int
+update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
+{
+ return 0;
+}
+
+#define UPDATE_TG 0x0
+#define SKIP_AGE_LOAD 0x0
+
+static inline void update_load_avg(struct sched_entity *se, int not_used1){}
static inline void
enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
static inline void
@@ -4186,9 +4610,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* Update run-time statistics of the 'current'.
*/
update_curr(cfs_rq);
+ update_load_avg(se, UPDATE_TG);
enqueue_entity_load_avg(cfs_rq, se);
+ update_cfs_shares(se);
account_entity_enqueue(cfs_rq, se);
- update_cfs_shares(cfs_rq);
if (flags & ENQUEUE_WAKEUP) {
place_entity(cfs_rq, se, 0);
@@ -4261,6 +4686,16 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
* Update run-time statistics of the 'current'.
*/
update_curr(cfs_rq);
+
+ /*
+ * When dequeuing a sched_entity, we must:
+ * - Update loads to have both entity and cfs_rq synced with now.
+ * - Substract its load from the cfs_rq->runnable_avg.
+ * - Substract its previous weight from cfs_rq->load.weight.
+ * - For group entity, update its weight to reflect the new share
+ * of its group cfs_rq.
+ */
+ update_load_avg(se, UPDATE_TG);
dequeue_entity_load_avg(cfs_rq, se);
update_stats_dequeue(cfs_rq, se);
@@ -4296,7 +4731,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
return_cfs_rq_runtime(cfs_rq);
update_min_vruntime(cfs_rq);
- update_cfs_shares(cfs_rq);
+ update_cfs_shares(se);
}
/*
@@ -4351,7 +4786,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
*/
update_stats_wait_end(cfs_rq, se);
__dequeue_entity(cfs_rq, se);
- update_load_avg(se, 1);
+ update_load_avg(se, UPDATE_TG);
}
update_stats_curr_start(cfs_rq, se);
@@ -4467,8 +4902,8 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
/*
* Ensure that runnable average is periodically updated.
*/
- update_load_avg(curr, 1);
- update_cfs_shares(cfs_rq);
+ update_load_avg(curr, UPDATE_TG);
+ update_cfs_shares(curr);
#ifdef CONFIG_SCHED_HRTICK
/*
@@ -5372,7 +5807,7 @@ static inline void hrtick_update(struct rq *rq)
#ifdef CONFIG_SMP
static bool cpu_overutilized(int cpu);
-static inline unsigned long boosted_cpu_util(int cpu);
+unsigned long boosted_cpu_util(int cpu);
#else
#define boosted_cpu_util(cpu) cpu_util(cpu)
#endif
@@ -5409,6 +5844,14 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
int task_wakeup = flags & ENQUEUE_WAKEUP;
#endif
+ /*
+ * If in_iowait is set, the code below may not trigger any cpufreq
+ * utilization updates, so do it here explicitly with the IOWAIT flag
+ * passed.
+ */
+ if (p->in_iowait)
+ cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_IOWAIT);
+
for_each_sched_entity(se) {
if (se->on_rq)
break;
@@ -5437,8 +5880,8 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
if (cfs_rq_throttled(cfs_rq))
break;
- update_load_avg(se, 1);
- update_cfs_shares(cfs_rq);
+ update_load_avg(se, UPDATE_TG);
+ update_cfs_shares(se);
}
if (!se) {
@@ -5543,8 +5986,8 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
if (cfs_rq_throttled(cfs_rq))
break;
- update_load_avg(se, 1);
- update_cfs_shares(cfs_rq);
+ update_load_avg(se, UPDATE_TG);
+ update_cfs_shares(se);
}
if (!se) {
@@ -6150,15 +6593,7 @@ static int sched_group_energy(struct energy_env *eenv)
*/
sd = rcu_dereference(per_cpu(sd_scs, cpu));
- if (!sd)
- /*
- * We most probably raced with hotplug; returning a
- * wrong energy estimation is better than entering an
- * infinite loop.
- */
- return -EINVAL;
-
- if (sd->parent)
+ if (sd && sd->parent)
sg_shared_cap = sd->parent->groups;
for_each_domain(cpu, sd) {
@@ -6213,6 +6648,14 @@ static int sched_group_energy(struct energy_env *eenv)
} while (sg = sg->next, sg != sd->groups);
}
+
+ /*
+ * If we raced with hotplug and got an sd NULL-pointer;
+ * returning a wrong energy estimation is better than
+ * entering an infinite loop.
+ */
+ if (cpumask_test_cpu(cpu, &visit_cpus))
+ return -EINVAL;
next_cpu:
cpumask_clear_cpu(cpu, &visit_cpus);
continue;
@@ -6239,6 +6682,7 @@ static inline int __energy_diff(struct energy_env *eenv)
struct sched_domain *sd;
struct sched_group *sg;
int sd_cpu = -1, energy_before = 0, energy_after = 0;
+ int diff, margin;
struct energy_env eenv_before = {
.util_delta = 0,
@@ -6281,12 +6725,22 @@ static inline int __energy_diff(struct energy_env *eenv)
eenv->nrg.after = energy_after;
eenv->nrg.diff = eenv->nrg.after - eenv->nrg.before;
eenv->payoff = 0;
-
+#ifndef CONFIG_SCHED_TUNE
trace_sched_energy_diff(eenv->task,
eenv->src_cpu, eenv->dst_cpu, eenv->util_delta,
eenv->nrg.before, eenv->nrg.after, eenv->nrg.diff,
eenv->cap.before, eenv->cap.after, eenv->cap.delta,
eenv->nrg.delta, eenv->payoff);
+#endif
+ /*
+ * Dead-zone margin preventing too many migrations.
+ */
+
+ margin = eenv->nrg.before >> 6; /* ~1.56% */
+
+ diff = eenv->nrg.after - eenv->nrg.before;
+
+ eenv->nrg.diff = (abs(diff) < margin) ? 0 : eenv->nrg.diff;
return eenv->nrg.diff;
}
@@ -6294,30 +6748,37 @@ static inline int __energy_diff(struct energy_env *eenv)
#ifdef CONFIG_SCHED_TUNE
struct target_nrg schedtune_target_nrg;
-
+extern bool schedtune_initialized;
/*
* System energy normalization
- * Returns the normalized value, in the range [0..SCHED_LOAD_SCALE],
+ * Returns the normalized value, in the range [0..SCHED_CAPACITY_SCALE],
* corresponding to the specified energy variation.
*/
static inline int
normalize_energy(int energy_diff)
{
u32 normalized_nrg;
+
+ /* during early setup, we don't know the extents */
+ if (unlikely(!schedtune_initialized))
+ return energy_diff < 0 ? -1 : 1 ;
+
#ifdef CONFIG_SCHED_DEBUG
+ {
int max_delta;
/* Check for boundaries */
max_delta = schedtune_target_nrg.max_power;
max_delta -= schedtune_target_nrg.min_power;
WARN_ON(abs(energy_diff) >= max_delta);
+ }
#endif
/* Do scaling using positive numbers to increase the range */
normalized_nrg = (energy_diff < 0) ? -energy_diff : energy_diff;
/* Scale by energy magnitude */
- normalized_nrg <<= SCHED_LOAD_SHIFT;
+ normalized_nrg <<= SCHED_CAPACITY_SHIFT;
/* Normalize on max energy for target platform */
normalized_nrg = reciprocal_divide(
@@ -6348,6 +6809,12 @@ energy_diff(struct energy_env *eenv)
eenv->cap.delta,
eenv->task);
+ trace_sched_energy_diff(eenv->task,
+ eenv->src_cpu, eenv->dst_cpu, eenv->util_delta,
+ eenv->nrg.before, eenv->nrg.after, eenv->nrg.diff,
+ eenv->cap.before, eenv->cap.after, eenv->cap.delta,
+ eenv->nrg.delta, eenv->payoff);
+
/*
* When SchedTune is enabled, the energy_diff() function will return
* the computed energy payoff value. Since the energy_diff() return
@@ -6387,18 +6854,18 @@ static int wake_wide(struct task_struct *p)
return 1;
}
-static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
+static int wake_affine(struct sched_domain *sd, struct task_struct *p,
+ int prev_cpu, int sync)
{
s64 this_load, load;
s64 this_eff_load, prev_eff_load;
- int idx, this_cpu, prev_cpu;
+ int idx, this_cpu;
struct task_group *tg;
unsigned long weight;
int balanced;
idx = sd->wake_idx;
this_cpu = smp_processor_id();
- prev_cpu = task_cpu(p);
load = source_load(prev_cpu, idx);
this_load = target_load(this_cpu, idx);
@@ -6458,8 +6925,6 @@ static inline unsigned long task_util(struct task_struct *p)
return p->se.avg.util_avg;
}
-unsigned int capacity_margin = 1280; /* ~20% margin */
-
static inline unsigned long boosted_task_util(struct task_struct *task);
static inline bool __task_fits(struct task_struct *p, int cpu, int util)
@@ -6485,11 +6950,6 @@ static inline bool task_fits_max(struct task_struct *p, int cpu)
return __task_fits(p, cpu, 0);
}
-static inline bool task_fits_spare(struct task_struct *p, int cpu)
-{
- return __task_fits(p, cpu, cpu_util(cpu));
-}
-
static bool cpu_overutilized(int cpu)
{
return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * capacity_margin);
@@ -6497,6 +6957,8 @@ static bool cpu_overutilized(int cpu)
#ifdef CONFIG_SCHED_TUNE
+struct reciprocal_value schedtune_spc_rdiv;
+
static long
schedtune_margin(unsigned long signal, long boost)
{
@@ -6507,29 +6969,16 @@ schedtune_margin(unsigned long signal, long boost)
*
* The Boost (B) value is used to compute a Margin (M) which is
* proportional to the complement of the original Signal (S):
- * M = B * (SCHED_LOAD_SCALE - S), if B is positive
- * M = B * S, if B is negative
+ * M = B * (SCHED_CAPACITY_SCALE - S)
* The obtained M could be used by the caller to "boost" S.
*/
if (boost >= 0) {
- margin = SCHED_LOAD_SCALE - signal;
+ margin = SCHED_CAPACITY_SCALE - signal;
margin *= boost;
} else
margin = -signal * boost;
- /*
- * Fast integer division by constant:
- * Constant : (C) = 100
- * Precision : 0.1% (P) = 0.1
- * Reference : C * 100 / P (R) = 100000
- *
- * Thus:
- * Shift bits : ceil(log(R,2)) (S) = 17
- * Mult const : round(2^S/C) (M) = 1311
- *
- *
- */
- margin *= 1311;
- margin >>= 17;
+
+ margin = reciprocal_divide(margin, schedtune_spc_rdiv);
if (boost < 0)
margin *= -1;
@@ -6579,7 +7028,7 @@ schedtune_task_margin(struct task_struct *task)
#endif /* CONFIG_SCHED_TUNE */
-static inline unsigned long
+unsigned long
boosted_cpu_util(int cpu)
{
unsigned long util = cpu_util(cpu);
@@ -6601,6 +7050,13 @@ boosted_task_util(struct task_struct *task)
return util + margin;
}
+static int cpu_util_wake(int cpu, struct task_struct *p);
+
+static unsigned long capacity_spare_wake(int cpu, struct task_struct *p)
+{
+ return capacity_orig_of(cpu) - cpu_util_wake(cpu, p);
+}
+
/*
* find_idlest_group finds and returns the least busy CPU group within the
* domain.
@@ -6610,10 +7066,9 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
int this_cpu, int sd_flag)
{
struct sched_group *idlest = NULL, *group = sd->groups;
- struct sched_group *fit_group = NULL, *spare_group = NULL;
+ struct sched_group *most_spare_sg = NULL;
unsigned long min_load = ULONG_MAX, this_load = 0;
- unsigned long fit_capacity = ULONG_MAX;
- unsigned long max_spare_capacity = capacity_margin - SCHED_LOAD_SCALE;
+ unsigned long most_spare = 0, this_spare = 0;
int load_idx = sd->forkexec_idx;
int imbalance = 100 + (sd->imbalance_pct-100)/2;
@@ -6621,7 +7076,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
load_idx = sd->wake_idx;
do {
- unsigned long load, avg_load, spare_capacity;
+ unsigned long load, avg_load, spare_cap, max_spare_cap;
int local_group;
int i;
@@ -6633,8 +7088,12 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
local_group = cpumask_test_cpu(this_cpu,
sched_group_cpus(group));
- /* Tally up the load of all CPUs in the group */
+ /*
+ * Tally up the load of all CPUs in the group and find
+ * the group containing the CPU with most spare capacity.
+ */
avg_load = 0;
+ max_spare_cap = 0;
for_each_cpu(i, sched_group_cpus(group)) {
/* Bias balancing toward cpus of our domain */
@@ -6645,24 +7104,10 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
avg_load += load;
- /*
- * Look for most energy-efficient group that can fit
- * that can fit the task.
- */
- if (capacity_of(i) < fit_capacity && task_fits_spare(p, i)) {
- fit_capacity = capacity_of(i);
- fit_group = group;
- }
+ spare_cap = capacity_spare_wake(i, p);
- /*
- * Look for group which has most spare capacity on a
- * single cpu.
- */
- spare_capacity = capacity_of(i) - cpu_util(i);
- if (spare_capacity > max_spare_capacity) {
- max_spare_capacity = spare_capacity;
- spare_group = group;
- }
+ if (spare_cap > max_spare_cap)
+ max_spare_cap = spare_cap;
}
/* Adjust by relative CPU capacity of the group */
@@ -6670,17 +7115,32 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
if (local_group) {
this_load = avg_load;
- } else if (avg_load < min_load) {
- min_load = avg_load;
- idlest = group;
+ this_spare = max_spare_cap;
+ } else {
+ if (avg_load < min_load) {
+ min_load = avg_load;
+ idlest = group;
+ }
+
+ if (most_spare < max_spare_cap) {
+ most_spare = max_spare_cap;
+ most_spare_sg = group;
+ }
}
} while (group = group->next, group != sd->groups);
- if (fit_group)
- return fit_group;
-
- if (spare_group)
- return spare_group;
+ /*
+ * The cross-over point between using spare capacity or least load
+ * is too conservative for high utilization tasks on partially
+ * utilized systems if we require spare_capacity > task_util(p),
+ * so we allow for some task stuffing by using
+ * spare_capacity > task_util(p)/2.
+ */
+ if (this_spare > task_util(p) / 2 &&
+ imbalance*this_spare > 100*most_spare)
+ return NULL;
+ else if (most_spare > task_util(p) / 2)
+ return most_spare_sg;
if (!idlest || 100*this_load < imbalance*min_load)
return NULL;
@@ -6700,9 +7160,13 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
int shallowest_idle_cpu = -1;
int i;
+ /* Check if we have any choice: */
+ if (group->group_weight == 1)
+ return cpumask_first(sched_group_cpus(group));
+
/* Traverse only the allowed CPUs */
for_each_cpu_and(i, sched_group_cpus(group), tsk_cpus_allowed(p)) {
- if (task_fits_spare(p, i)) {
+ if (idle_cpu(i)) {
struct rq *rq = cpu_rq(i);
struct cpuidle_state *idle = idle_get_state(rq);
if (idle && idle->exit_latency < min_exit_latency) {
@@ -6714,8 +7178,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
min_exit_latency = idle->exit_latency;
latest_idle_timestamp = rq->idle_stamp;
shallowest_idle_cpu = i;
- } else if (idle_cpu(i) &&
- (!idle || idle->exit_latency == min_exit_latency) &&
+ } else if ((!idle || idle->exit_latency == min_exit_latency) &&
rq->idle_stamp > latest_idle_timestamp) {
/*
* If equal or no active idle state, then
@@ -6724,13 +7187,6 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
*/
latest_idle_timestamp = rq->idle_stamp;
shallowest_idle_cpu = i;
- } else if (shallowest_idle_cpu == -1) {
- /*
- * If we haven't found an idle CPU yet
- * pick a non-idle one that can fit the task as
- * fallback.
- */
- shallowest_idle_cpu = i;
}
} else if (shallowest_idle_cpu == -1) {
load = weighted_cpuload(i);
@@ -6747,24 +7203,32 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
/*
* Try and locate an idle CPU in the sched_domain.
*/
-static int select_idle_sibling(struct task_struct *p, int target)
+static int select_idle_sibling(struct task_struct *p, int prev, int target)
{
struct sched_domain *sd;
struct sched_group *sg;
- int i = task_cpu(p);
- int best_idle = -1;
- int best_idle_cstate = -1;
- int best_idle_capacity = INT_MAX;
+ int best_idle_cpu = -1;
+ int best_idle_cstate = INT_MAX;
+ unsigned long best_idle_capacity = ULONG_MAX;
+
+ schedstat_inc(p, se.statistics.nr_wakeups_sis_attempts);
+ schedstat_inc(this_rq(), eas_stats.sis_attempts);
if (!sysctl_sched_cstate_aware) {
- if (idle_cpu(target))
+ if (idle_cpu(target)) {
+ schedstat_inc(p, se.statistics.nr_wakeups_sis_idle);
+ schedstat_inc(this_rq(), eas_stats.sis_idle);
return target;
+ }
/*
* If the prevous cpu is cache affine and idle, don't be stupid.
*/
- if (i != target && cpus_share_cache(i, target) && idle_cpu(i))
- return i;
+ if (prev != target && cpus_share_cache(prev, target) && idle_cpu(prev)) {
+ schedstat_inc(p, se.statistics.nr_wakeups_sis_cache_affine);
+ schedstat_inc(this_rq(), eas_stats.sis_cache_affine);
+ return prev;
+ }
}
if (!(current->flags & PF_WAKE_UP_IDLE) &&
@@ -6778,24 +7242,30 @@ static int select_idle_sibling(struct task_struct *p, int target)
for_each_lower_domain(sd) {
sg = sd->groups;
do {
+ int i;
if (!cpumask_intersects(sched_group_cpus(sg),
tsk_cpus_allowed(p)))
goto next;
if (sysctl_sched_cstate_aware) {
for_each_cpu_and(i, tsk_cpus_allowed(p), sched_group_cpus(sg)) {
- struct rq *rq = cpu_rq(i);
- int idle_idx = idle_get_state_idx(rq);
+ int idle_idx = idle_get_state_idx(cpu_rq(i));
unsigned long new_usage = boosted_task_util(p);
unsigned long capacity_orig = capacity_orig_of(i);
+
if (new_usage > capacity_orig || !idle_cpu(i))
goto next;
- if (i == target && new_usage <= capacity_curr_of(target))
+ if (i == target && new_usage <= capacity_curr_of(target)) {
+ schedstat_inc(p, se.statistics.nr_wakeups_sis_suff_cap);
+ schedstat_inc(this_rq(), eas_stats.sis_suff_cap);
+ schedstat_inc(sd, eas_stats.sis_suff_cap);
return target;
+ }
- if (best_idle < 0 || (idle_idx < best_idle_cstate && capacity_orig <= best_idle_capacity)) {
- best_idle = i;
+ if (idle_idx < best_idle_cstate &&
+ capacity_orig <= best_idle_capacity) {
+ best_idle_cpu = i;
best_idle_cstate = idle_idx;
best_idle_capacity = capacity_orig;
}
@@ -6808,231 +7278,283 @@ static int select_idle_sibling(struct task_struct *p, int target)
target = cpumask_first_and(sched_group_cpus(sg),
tsk_cpus_allowed(p));
+ schedstat_inc(p, se.statistics.nr_wakeups_sis_idle_cpu);
+ schedstat_inc(this_rq(), eas_stats.sis_idle_cpu);
+ schedstat_inc(sd, eas_stats.sis_idle_cpu);
goto done;
}
next:
sg = sg->next;
} while (sg != sd->groups);
}
- if (best_idle > 0)
- target = best_idle;
+
+ if (best_idle_cpu >= 0)
+ target = best_idle_cpu;
done:
+ schedstat_inc(p, se.statistics.nr_wakeups_sis_count);
+ schedstat_inc(this_rq(), eas_stats.sis_count);
+
return target;
}
-static inline int find_best_target(struct task_struct *p, bool boosted, bool prefer_idle)
+/*
+ * cpu_util_wake: Compute cpu utilization with any contributions from
+ * the waking task p removed.
+ */
+static int cpu_util_wake(int cpu, struct task_struct *p)
{
- int iter_cpu;
- int target_cpu = -1;
- int target_util = 0;
- int backup_capacity = 0;
- int best_idle_cpu = -1;
- int best_idle_cstate = INT_MAX;
- int backup_cpu = -1;
- unsigned long task_util_boosted, new_util;
-
- task_util_boosted = boosted_task_util(p);
- for (iter_cpu = 0; iter_cpu < NR_CPUS; iter_cpu++) {
- int cur_capacity;
- struct rq *rq;
- int idle_idx;
-
- /*
- * Iterate from higher cpus for boosted tasks.
- */
- int i = boosted ? NR_CPUS-iter_cpu-1 : iter_cpu;
-
- if (!cpu_online(i) || !cpumask_test_cpu(i, tsk_cpus_allowed(p)))
- continue;
+ unsigned long util, capacity;
- /*
- * p's blocked utilization is still accounted for on prev_cpu
- * so prev_cpu will receive a negative bias due to the double
- * accounting. However, the blocked utilization may be zero.
- */
- new_util = cpu_util(i) + task_util_boosted;
-
- /*
- * Ensure minimum capacity to grant the required boost.
- * The target CPU can be already at a capacity level higher
- * than the one required to boost the task.
- */
- if (new_util > capacity_orig_of(i))
- continue;
+#ifdef CONFIG_SCHED_WALT
+ /*
+ * WALT does not decay idle tasks in the same manner
+ * as PELT, so it makes little sense to subtract task
+ * utilization from cpu utilization. Instead just use
+ * cpu_util for this case.
+ */
+ if (!walt_disabled && sysctl_sched_use_walt_cpu_util)
+ return cpu_util(cpu);
+#endif
+ /* Task has no contribution or is new */
+ if (cpu != task_cpu(p) || !p->se.avg.last_update_time)
+ return cpu_util(cpu);
- /*
- * Unconditionally favoring tasks that prefer idle cpus to
- * improve latency.
- */
- if (idle_cpu(i) && prefer_idle) {
- if (best_idle_cpu < 0)
- best_idle_cpu = i;
- continue;
- }
+ capacity = capacity_orig_of(cpu);
+ util = max_t(long, cpu_util(cpu) - task_util(p), 0);
- cur_capacity = capacity_curr_of(i);
- rq = cpu_rq(i);
- idle_idx = idle_get_state_idx(rq);
+ return (util >= capacity) ? capacity : util;
+}
- if (new_util < cur_capacity) {
- if (cpu_rq(i)->nr_running) {
- if (prefer_idle) {
- /* Find a target cpu with highest
- * utilization.
- */
- if (target_util == 0 ||
- target_util < new_util) {
- target_cpu = i;
- target_util = new_util;
- }
- } else {
- /* Find a target cpu with lowest
- * utilization.
- */
- if (target_util == 0 ||
- target_util > new_util) {
- target_cpu = i;
- target_util = new_util;
- }
- }
- } else if (!prefer_idle) {
- if (best_idle_cpu < 0 ||
- (sysctl_sched_cstate_aware &&
- best_idle_cstate > idle_idx)) {
- best_idle_cstate = idle_idx;
- best_idle_cpu = i;
- }
- }
- } else if (backup_capacity == 0 ||
- backup_capacity > cur_capacity) {
- // Find a backup cpu with least capacity.
- backup_capacity = cur_capacity;
- backup_cpu = i;
- }
- }
+static int start_cpu(bool boosted)
+{
+ struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
- if (prefer_idle && best_idle_cpu >= 0)
- target_cpu = best_idle_cpu;
- else if (target_cpu < 0)
- target_cpu = best_idle_cpu >= 0 ? best_idle_cpu : backup_cpu;
+ RCU_LOCKDEP_WARN(rcu_read_lock_sched_held(),
+ "sched RCU must be held");
- return target_cpu;
+ return boosted ? rd->max_cap_orig_cpu : rd->min_cap_orig_cpu;
}
-static int energy_aware_wake_cpu(struct task_struct *p, int target, int sync)
+static inline int find_best_target(struct task_struct *p, bool boosted, bool prefer_idle)
{
+ int target_cpu = -1;
+ unsigned long target_util = prefer_idle ? ULONG_MAX : 0;
+ unsigned long backup_capacity = ULONG_MAX;
+ int best_idle_cpu = -1;
+ int best_idle_cstate = INT_MAX;
+ int backup_cpu = -1;
+ unsigned long min_util = boosted_task_util(p);
struct sched_domain *sd;
- struct sched_group *sg, *sg_target;
- int target_max_cap = INT_MAX;
- int target_cpu = task_cpu(p);
- unsigned long task_util_boosted, new_util;
- int i;
+ struct sched_group *sg;
+ int cpu = start_cpu(boosted);
- if (sysctl_sched_sync_hint_enable && sync) {
- int cpu = smp_processor_id();
- cpumask_t search_cpus;
- cpumask_and(&search_cpus, tsk_cpus_allowed(p), cpu_online_mask);
- if (cpumask_test_cpu(cpu, &search_cpus))
- return cpu;
+ schedstat_inc(p, se.statistics.nr_wakeups_fbt_attempts);
+ schedstat_inc(this_rq(), eas_stats.fbt_attempts);
+
+ if (cpu < 0) {
+ schedstat_inc(p, se.statistics.nr_wakeups_fbt_no_cpu);
+ schedstat_inc(this_rq(), eas_stats.fbt_no_cpu);
+ return target_cpu;
}
- sd = rcu_dereference(per_cpu(sd_ea, task_cpu(p)));
+ sd = rcu_dereference(per_cpu(sd_ea, cpu));
- if (!sd)
- return target;
+ if (!sd) {
+ schedstat_inc(p, se.statistics.nr_wakeups_fbt_no_sd);
+ schedstat_inc(this_rq(), eas_stats.fbt_no_sd);
+ return target_cpu;
+ }
sg = sd->groups;
- sg_target = sg;
- if (sysctl_sched_is_big_little) {
+ do {
+ int i;
- /*
- * Find group with sufficient capacity. We only get here if no cpu is
- * overutilized. We may end up overutilizing a cpu by adding the task,
- * but that should not be any worse than select_idle_sibling().
- * load_balance() should sort it out later as we get above the tipping
- * point.
- */
- do {
- /* Assuming all cpus are the same in group */
- int max_cap_cpu = group_first_cpu(sg);
+ for_each_cpu_and(i, tsk_cpus_allowed(p), sched_group_cpus(sg)) {
+ unsigned long cur_capacity, new_util, wake_util;
+ unsigned long min_wake_util = ULONG_MAX;
- /*
- * Assume smaller max capacity means more energy-efficient.
- * Ideally we should query the energy model for the right
- * answer but it easily ends up in an exhaustive search.
- */
- if (capacity_of(max_cap_cpu) < target_max_cap &&
- task_fits_max(p, max_cap_cpu)) {
- sg_target = sg;
- target_max_cap = capacity_of(max_cap_cpu);
- }
- } while (sg = sg->next, sg != sd->groups);
+ if (!cpu_online(i))
+ continue;
- task_util_boosted = boosted_task_util(p);
- /* Find cpu with sufficient capacity */
- for_each_cpu_and(i, tsk_cpus_allowed(p), sched_group_cpus(sg_target)) {
/*
* p's blocked utilization is still accounted for on prev_cpu
* so prev_cpu will receive a negative bias due to the double
* accounting. However, the blocked utilization may be zero.
*/
- new_util = cpu_util(i) + task_util_boosted;
+ wake_util = cpu_util_wake(i, p);
+ new_util = wake_util + task_util(p);
/*
* Ensure minimum capacity to grant the required boost.
* The target CPU can be already at a capacity level higher
* than the one required to boost the task.
*/
+ new_util = max(min_util, new_util);
+
if (new_util > capacity_orig_of(i))
continue;
- if (new_util < capacity_curr_of(i)) {
- target_cpu = i;
- if (cpu_rq(i)->nr_running)
- break;
+ /*
+ * Unconditionally favoring tasks that prefer idle cpus to
+ * improve latency.
+ */
+ if (idle_cpu(i) && prefer_idle) {
+ schedstat_inc(p, se.statistics.nr_wakeups_fbt_pref_idle);
+ schedstat_inc(this_rq(), eas_stats.fbt_pref_idle);
+ return i;
+ }
+
+ cur_capacity = capacity_curr_of(i);
+
+ if (new_util < cur_capacity) {
+ if (cpu_rq(i)->nr_running) {
+ /*
+ * Find a target cpu with the lowest/highest
+ * utilization if prefer_idle/!prefer_idle.
+ */
+ if (prefer_idle) {
+ /* Favor the CPU that last ran the task */
+ if (new_util > target_util ||
+ wake_util > min_wake_util)
+ continue;
+ min_wake_util = wake_util;
+ target_util = new_util;
+ target_cpu = i;
+ } else if (target_util < new_util) {
+ target_util = new_util;
+ target_cpu = i;
+ }
+ } else if (!prefer_idle) {
+ int idle_idx = idle_get_state_idx(cpu_rq(i));
+
+ if (best_idle_cpu < 0 ||
+ (sysctl_sched_cstate_aware &&
+ best_idle_cstate > idle_idx)) {
+ best_idle_cstate = idle_idx;
+ best_idle_cpu = i;
+ }
+ }
+ } else if (backup_capacity > cur_capacity) {
+ /* Find a backup cpu with least capacity. */
+ backup_capacity = cur_capacity;
+ backup_cpu = i;
}
+ }
+ } while (sg = sg->next, sg != sd->groups);
+
+ if (target_cpu < 0)
+ target_cpu = best_idle_cpu >= 0 ? best_idle_cpu : backup_cpu;
+
+ if (target_cpu >= 0) {
+ schedstat_inc(p, se.statistics.nr_wakeups_fbt_count);
+ schedstat_inc(this_rq(), eas_stats.fbt_count);
+ }
+
+ return target_cpu;
+}
+
+/*
+ * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
+ * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
+ *
+ * In that case WAKE_AFFINE doesn't make sense and we'll let
+ * BALANCE_WAKE sort things out.
+ */
+static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
+{
+ long min_cap, max_cap;
- /* cpu has capacity at higher OPP, keep it as fallback */
- if (target_cpu == task_cpu(p))
- target_cpu = i;
+ min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu));
+ max_cap = cpu_rq(cpu)->rd->max_cpu_capacity.val;
+
+ /* Minimum capacity is close to max, no need to abort wake_affine */
+ if (max_cap - min_cap < max_cap >> 3)
+ return 0;
+
+ /* Bring task utilization in sync with prev_cpu */
+ sync_entity_load_avg(&p->se);
+
+ return min_cap * 1024 < task_util(p) * capacity_margin;
+}
+
+static int select_energy_cpu_brute(struct task_struct *p, int prev_cpu, int sync)
+{
+ struct sched_domain *sd;
+ int target_cpu = prev_cpu, tmp_target;
+ bool boosted, prefer_idle;
+
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_attempts);
+ schedstat_inc(this_rq(), eas_stats.secb_attempts);
+
+ if (sysctl_sched_sync_hint_enable && sync) {
+ int cpu = smp_processor_id();
+
+ if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) {
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_sync);
+ schedstat_inc(this_rq(), eas_stats.secb_sync);
+ return cpu;
}
- } else {
- /*
- * Find a cpu with sufficient capacity
- */
+ }
+
+ rcu_read_lock();
#ifdef CONFIG_CGROUP_SCHEDTUNE
- bool boosted = schedtune_task_boost(p) > 0;
- bool prefer_idle = schedtune_prefer_idle(p) > 0;
+ boosted = schedtune_task_boost(p) > 0;
+ prefer_idle = schedtune_prefer_idle(p) > 0;
#else
- bool boosted = 0;
- bool prefer_idle = 0;
+ boosted = get_sysctl_sched_cfs_boost() > 0;
+ prefer_idle = 0;
#endif
- int tmp_target = find_best_target(p, boosted, prefer_idle);
- if (tmp_target >= 0) {
- target_cpu = tmp_target;
- if ((boosted || prefer_idle) && idle_cpu(target_cpu))
- return target_cpu;
+
+ sd = rcu_dereference(per_cpu(sd_ea, prev_cpu));
+ /* Find a cpu with sufficient capacity */
+ tmp_target = find_best_target(p, boosted, prefer_idle);
+
+ if (!sd)
+ goto unlock;
+ if (tmp_target >= 0) {
+ target_cpu = tmp_target;
+ if ((boosted || prefer_idle) && idle_cpu(target_cpu)) {
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_idle_bt);
+ schedstat_inc(this_rq(), eas_stats.secb_idle_bt);
+ goto unlock;
}
}
- if (target_cpu != task_cpu(p)) {
+ if (target_cpu != prev_cpu) {
struct energy_env eenv = {
- .util_delta = task_util(p),
- .src_cpu = task_cpu(p),
- .dst_cpu = target_cpu,
- .task = p,
+ .util_delta = task_util(p),
+ .src_cpu = prev_cpu,
+ .dst_cpu = target_cpu,
+ .task = p,
};
/* Not enough spare capacity on previous cpu */
- if (cpu_overutilized(task_cpu(p)))
- return target_cpu;
+ if (cpu_overutilized(prev_cpu)) {
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_insuff_cap);
+ schedstat_inc(this_rq(), eas_stats.secb_insuff_cap);
+ goto unlock;
+ }
+
+ if (energy_diff(&eenv) >= 0) {
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_no_nrg_sav);
+ schedstat_inc(this_rq(), eas_stats.secb_no_nrg_sav);
+ target_cpu = prev_cpu;
+ goto unlock;
+ }
- if (energy_diff(&eenv) >= 0)
- return task_cpu(p);
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_nrg_sav);
+ schedstat_inc(this_rq(), eas_stats.secb_nrg_sav);
+ goto unlock;
}
+ schedstat_inc(p, se.statistics.nr_wakeups_secb_count);
+ schedstat_inc(this_rq(), eas_stats.secb_count);
+
+unlock:
+ rcu_read_unlock();
+
return target_cpu;
}
@@ -7061,10 +7583,19 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
return select_best_cpu(p, prev_cpu, 0, sync);
#endif
- if (sd_flag & SD_BALANCE_WAKE)
- want_affine = (!wake_wide(p) && task_fits_max(p, cpu) &&
- cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) ||
- energy_aware();
+ if (sd_flag & SD_BALANCE_WAKE) {
+ /*
+ * do wake_cap unconditionally as it causes task and cpu
+ * utilization to be synced, and we need that for energy
+ * aware wakeups
+ */
+ int _wake_cap = wake_cap(p, cpu, prev_cpu);
+ want_affine = !wake_wide(p) && !_wake_cap
+ && cpumask_test_cpu(cpu, tsk_cpus_allowed(p));
+ }
+
+ if (energy_aware() && !(cpu_rq(prev_cpu)->rd->overutilized))
+ return select_energy_cpu_brute(p, prev_cpu, sync);
rcu_read_lock();
for_each_domain(cpu, tmp) {
@@ -7089,49 +7620,65 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
if (affine_sd) {
sd = NULL; /* Prefer wake_affine over balance flags */
- if (cpu != prev_cpu && wake_affine(affine_sd, p, sync))
+ if (cpu != prev_cpu && wake_affine(affine_sd, p, prev_cpu, sync))
new_cpu = cpu;
}
if (!sd) {
- if (energy_aware() && !cpu_rq(cpu)->rd->overutilized)
- new_cpu = energy_aware_wake_cpu(p, prev_cpu, sync);
- else if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */
- new_cpu = select_idle_sibling(p, new_cpu);
+ if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */
+ new_cpu = select_idle_sibling(p, prev_cpu, new_cpu);
- } else while (sd) {
- struct sched_group *group;
- int weight;
+ } else {
+ int wu = sd_flag & SD_BALANCE_WAKE;
+ int cas_cpu = -1;
- if (!(sd->flags & sd_flag)) {
- sd = sd->child;
- continue;
+ if (wu) {
+ schedstat_inc(p, se.statistics.nr_wakeups_cas_attempts);
+ schedstat_inc(this_rq(), eas_stats.cas_attempts);
}
- group = find_idlest_group(sd, p, cpu, sd_flag);
- if (!group) {
- sd = sd->child;
- continue;
- }
+ while (sd) {
+ struct sched_group *group;
+ int weight;
- new_cpu = find_idlest_cpu(group, p, cpu);
- if (new_cpu == -1 || new_cpu == cpu) {
- /* Now try balancing at a lower domain level of cpu */
- sd = sd->child;
- continue;
+ if (wu)
+ schedstat_inc(sd, eas_stats.cas_attempts);
+
+ if (!(sd->flags & sd_flag)) {
+ sd = sd->child;
+ continue;
+ }
+
+ group = find_idlest_group(sd, p, cpu, sd_flag);
+ if (!group) {
+ sd = sd->child;
+ continue;
+ }
+
+ new_cpu = find_idlest_cpu(group, p, cpu);
+ if (new_cpu == -1 || new_cpu == cpu) {
+ /* Now try balancing at a lower domain level of cpu */
+ sd = sd->child;
+ continue;
+ }
+
+ /* Now try balancing at a lower domain level of new_cpu */
+ cpu = cas_cpu = new_cpu;
+ weight = sd->span_weight;
+ sd = NULL;
+ for_each_domain(cpu, tmp) {
+ if (weight <= tmp->span_weight)
+ break;
+ if (tmp->flags & sd_flag)
+ sd = tmp;
+ }
+ /* while loop will break here if sd == NULL */
}
- /* Now try balancing at a lower domain level of new_cpu */
- cpu = new_cpu;
- weight = sd->span_weight;
- sd = NULL;
- for_each_domain(cpu, tmp) {
- if (weight <= tmp->span_weight)
- break;
- if (tmp->flags & sd_flag)
- sd = tmp;
+ if (wu && (cas_cpu >= 0)) {
+ schedstat_inc(p, se.statistics.nr_wakeups_cas_count);
+ schedstat_inc(this_rq(), eas_stats.cas_count);
}
- /* while loop will break here if sd == NULL */
}
rcu_read_unlock();
@@ -8134,8 +8681,13 @@ static void update_blocked_averages(int cpu)
if (throttled_hierarchy(cfs_rq))
continue;
- if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq))
+ if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq,
+ true))
update_tg_load_avg(cfs_rq, 0);
+
+ /* Propagate pending load changes to the parent */
+ if (cfs_rq->tg->se[cpu])
+ update_load_avg(cfs_rq->tg->se[cpu], 0);
}
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
@@ -8195,7 +8747,7 @@ static inline void update_blocked_averages(int cpu)
raw_spin_lock_irqsave(&rq->lock, flags);
update_rq_clock(rq);
- update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq);
+ update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true);
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
@@ -8433,13 +8985,14 @@ skip_unlock: __attribute__ ((unused));
cpu_rq(cpu)->cpu_capacity = capacity;
sdg->sgc->capacity = capacity;
sdg->sgc->max_capacity = capacity;
+ sdg->sgc->min_capacity = capacity;
}
void update_group_capacity(struct sched_domain *sd, int cpu)
{
struct sched_domain *child = sd->child;
struct sched_group *group, *sdg = sd->groups;
- unsigned long capacity, max_capacity;
+ unsigned long capacity, max_capacity, min_capacity;
unsigned long interval;
interval = msecs_to_jiffies(sd->balance_interval);
@@ -8453,6 +9006,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
capacity = 0;
max_capacity = 0;
+ min_capacity = ULONG_MAX;
if (child->flags & SD_OVERLAP) {
/*
@@ -8485,6 +9039,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
}
max_capacity = max(capacity, max_capacity);
+ min_capacity = min(capacity, min_capacity);
}
} else {
/*
@@ -8502,6 +9057,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
if (!cpu_isolated(cpumask_first(cpus))) {
capacity += sgc->capacity;
max_capacity = max(sgc->max_capacity, max_capacity);
+ min_capacity = min(sgc->min_capacity, min_capacity);
}
group = group->next;
} while (group != child->groups);
@@ -8509,6 +9065,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu)
sdg->sgc->capacity = capacity;
sdg->sgc->max_capacity = max_capacity;
+ sdg->sgc->min_capacity = min_capacity;
}
/*
@@ -8790,15 +9347,21 @@ static bool update_sd_pick_busiest(struct lb_env *env,
if (sgs->avg_load <= busiest->avg_load)
return false;
+ if (!(env->sd->flags & SD_ASYM_CPUCAPACITY))
+ goto asym_packing;
+
/*
- * Candiate sg has no more than one task per cpu and has higher
- * per-cpu capacity. No reason to pull tasks to less capable cpus.
+ * Candidate sg has no more than one task per CPU and
+ * has higher per-CPU capacity. Migrating tasks to less
+ * capable CPUs may harm throughput. Maximize throughput,
+ * power/energy consequences are not considered.
*/
if (sgs->sum_nr_running <= sgs->group_weight &&
group_smaller_cpu_capacity(sds->local, sg))
return false;
}
+asym_packing:
/* This is the busiest node in its class. */
if (!(env->sd->flags & SD_ASYM_PACKING))
return true;
@@ -8849,6 +9412,9 @@ static inline enum fbq_type fbq_classify_rq(struct rq *rq)
}
#endif /* CONFIG_NUMA_BALANCING */
+#define lb_sd_parent(sd) \
+ (sd->parent && sd->parent->groups != sd->parent->groups->next)
+
/**
* update_sd_lb_stats - Update sched_domain's statistics for load balancing.
* @env: The load balancing environment.
@@ -8934,7 +9500,7 @@ next_group:
env->src_grp_nr_running = sds->busiest_stat.sum_nr_running;
- if (!env->sd->parent) {
+ if (!lb_sd_parent(env->sd)) {
/* update overload indicator if we are at root domain */
if (env->dst_rq->rd->overload != overload)
env->dst_rq->rd->overload = overload;
@@ -9523,7 +10089,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
int *continue_balancing)
{
int ld_moved = 0, cur_ld_moved, active_balance = 0;
- struct sched_domain *sd_parent = sd->parent;
+ struct sched_domain *sd_parent = lb_sd_parent(sd) ? sd->parent : NULL;
struct sched_group *group = NULL;
struct rq *busiest = NULL;
unsigned long flags;
@@ -10807,6 +11373,61 @@ static inline bool vruntime_normalized(struct task_struct *p)
return false;
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
+/*
+ * Propagate the changes of the sched_entity across the tg tree to make it
+ * visible to the root
+ */
+static void propagate_entity_cfs_rq(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq;
+
+ /* Start to propagate at parent */
+ se = se->parent;
+
+ for_each_sched_entity(se) {
+ cfs_rq = cfs_rq_of(se);
+
+ if (cfs_rq_throttled(cfs_rq))
+ break;
+
+ update_load_avg(se, UPDATE_TG);
+ }
+}
+#else
+static void propagate_entity_cfs_rq(struct sched_entity *se) { }
+#endif
+
+static void detach_entity_cfs_rq(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+ /* Catch up with the cfs_rq and remove our load when we leave */
+ update_load_avg(se, 0);
+ detach_entity_load_avg(cfs_rq, se);
+ update_tg_load_avg(cfs_rq, false);
+ propagate_entity_cfs_rq(se);
+}
+
+static void attach_entity_cfs_rq(struct sched_entity *se)
+{
+ struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ /*
+ * Since the real-depth could have been changed (only FAIR
+ * class maintain depth value), reset depth properly.
+ */
+ se->depth = se->parent ? se->parent->depth + 1 : 0;
+#endif
+
+ /* Synchronize entity with its cfs_rq */
+ update_load_avg(se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD);
+ attach_entity_load_avg(cfs_rq, se);
+ update_tg_load_avg(cfs_rq, false);
+ propagate_entity_cfs_rq(se);
+}
+
static void detach_task_cfs_rq(struct task_struct *p)
{
struct sched_entity *se = &p->se;
@@ -10821,8 +11442,7 @@ static void detach_task_cfs_rq(struct task_struct *p)
se->vruntime -= cfs_rq->min_vruntime;
}
- /* Catch up with the cfs_rq and remove our load when we leave */
- detach_entity_load_avg(cfs_rq, se);
+ detach_entity_cfs_rq(se);
}
static void attach_task_cfs_rq(struct task_struct *p)
@@ -10830,16 +11450,7 @@ static void attach_task_cfs_rq(struct task_struct *p)
struct sched_entity *se = &p->se;
struct cfs_rq *cfs_rq = cfs_rq_of(se);
-#ifdef CONFIG_FAIR_GROUP_SCHED
- /*
- * Since the real-depth could have been changed (only FAIR
- * class maintain depth value), reset depth properly.
- */
- se->depth = se->parent ? se->parent->depth + 1 : 0;
-#endif
-
- /* Synchronize task with its cfs_rq */
- attach_entity_load_avg(cfs_rq, se);
+ attach_entity_cfs_rq(se);
if (!vruntime_normalized(p))
se->vruntime += cfs_rq->min_vruntime;
@@ -10893,6 +11504,9 @@ void init_cfs_rq(struct cfs_rq *cfs_rq)
cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
#endif
#ifdef CONFIG_SMP
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ cfs_rq->propagate_avg = 0;
+#endif
atomic_long_set(&cfs_rq->removed_load_avg, 0);
atomic_long_set(&cfs_rq->removed_util_avg, 0);
#endif
@@ -10930,8 +11544,9 @@ void free_fair_sched_group(struct task_group *tg)
int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
{
- struct cfs_rq *cfs_rq;
struct sched_entity *se;
+ struct cfs_rq *cfs_rq;
+ struct rq *rq;
int i;
tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
@@ -10946,6 +11561,8 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
init_cfs_bandwidth(tg_cfs_bandwidth(tg));
for_each_possible_cpu(i) {
+ rq = cpu_rq(i);
+
cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
GFP_KERNEL, cpu_to_node(i));
if (!cfs_rq)
@@ -10959,6 +11576,10 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
init_cfs_rq(cfs_rq);
init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]);
init_entity_runnable_average(se);
+
+ raw_spin_lock_irq(&rq->lock);
+ post_init_entity_util_avg(se);
+ raw_spin_unlock_irq(&rq->lock);
}
return 1;
@@ -11055,8 +11676,10 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
/* Possible calls to update_curr() need rq clock */
update_rq_clock(rq);
- for_each_sched_entity(se)
- update_cfs_shares(group_cfs_rq(se));
+ for_each_sched_entity(se) {
+ update_load_avg(se, UPDATE_TG);
+ update_cfs_shares(se);
+ }
raw_spin_unlock_irqrestore(&rq->lock, flags);
}