]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - kernel/sched/core.c
Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetoot...
[karo-tx-linux.git] / kernel / sched / core.c
index c6b98793d6477fd60fe8122745c9db75007d3080..3bdf01b494fe29c267a0abe73828b02a799a737d 100644 (file)
@@ -535,7 +535,7 @@ static inline void init_hrtick(void)
        __old;                                                          \
 })
 
-#ifdef TIF_POLLING_NRFLAG
+#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
 /*
  * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
  * this avoids any races wrt polling state changes and thereby avoids
@@ -546,12 +546,44 @@ static bool set_nr_and_not_polling(struct task_struct *p)
        struct thread_info *ti = task_thread_info(p);
        return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG);
 }
+
+/*
+ * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set.
+ *
+ * If this returns true, then the idle task promises to call
+ * sched_ttwu_pending() and reschedule soon.
+ */
+static bool set_nr_if_polling(struct task_struct *p)
+{
+       struct thread_info *ti = task_thread_info(p);
+       typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags);
+
+       for (;;) {
+               if (!(val & _TIF_POLLING_NRFLAG))
+                       return false;
+               if (val & _TIF_NEED_RESCHED)
+                       return true;
+               old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED);
+               if (old == val)
+                       break;
+               val = old;
+       }
+       return true;
+}
+
 #else
 static bool set_nr_and_not_polling(struct task_struct *p)
 {
        set_tsk_need_resched(p);
        return true;
 }
+
+#ifdef CONFIG_SMP
+static bool set_nr_if_polling(struct task_struct *p)
+{
+       return false;
+}
+#endif
 #endif
 
 /*
@@ -580,6 +612,8 @@ void resched_task(struct task_struct *p)
 
        if (set_nr_and_not_polling(p))
                smp_send_reschedule(cpu);
+       else
+               trace_sched_wake_idle_without_ipi(cpu);
 }
 
 void resched_cpu(int cpu)
@@ -642,27 +676,10 @@ static void wake_up_idle_cpu(int cpu)
        if (cpu == smp_processor_id())
                return;
 
-       /*
-        * This is safe, as this function is called with the timer
-        * wheel base lock of (cpu) held. When the CPU is on the way
-        * to idle and has not yet set rq->curr to idle then it will
-        * be serialized on the timer wheel base lock and take the new
-        * timer into account automatically.
-        */
-       if (rq->curr != rq->idle)
-               return;
-
-       /*
-        * We can set TIF_RESCHED on the idle task of the other CPU
-        * lockless. The worst case is that the other CPU runs the
-        * idle task through an additional NOOP schedule()
-        */
-       set_tsk_need_resched(rq->idle);
-
-       /* NEED_RESCHED must be visible before we test polling */
-       smp_mb();
-       if (!tsk_is_polling(rq->idle))
+       if (set_nr_and_not_polling(rq->idle))
                smp_send_reschedule(cpu);
+       else
+               trace_sched_wake_idle_without_ipi(cpu);
 }
 
 static bool wake_up_full_nohz_cpu(int cpu)
@@ -888,7 +905,7 @@ static void update_rq_clock_task(struct rq *rq, s64 delta)
        rq->clock_task += delta;
 
 #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
-       if ((irq_delta + steal) && sched_feat(NONTASK_POWER))
+       if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY))
                sched_rt_avg_update(rq, irq_delta + steal);
 #endif
 }
@@ -1521,13 +1538,17 @@ static int ttwu_remote(struct task_struct *p, int wake_flags)
 }
 
 #ifdef CONFIG_SMP
-static void sched_ttwu_pending(void)
+void sched_ttwu_pending(void)
 {
        struct rq *rq = this_rq();
        struct llist_node *llist = llist_del_all(&rq->wake_list);
        struct task_struct *p;
+       unsigned long flags;
 
-       raw_spin_lock(&rq->lock);
+       if (!llist)
+               return;
+
+       raw_spin_lock_irqsave(&rq->lock, flags);
 
        while (llist) {
                p = llist_entry(llist, struct task_struct, wake_entry);
@@ -1535,7 +1556,7 @@ static void sched_ttwu_pending(void)
                ttwu_do_activate(rq, p, 0);
        }
 
-       raw_spin_unlock(&rq->lock);
+       raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 
 void scheduler_ipi(void)
@@ -1581,8 +1602,14 @@ void scheduler_ipi(void)
 
 static void ttwu_queue_remote(struct task_struct *p, int cpu)
 {
-       if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list))
-               smp_send_reschedule(cpu);
+       struct rq *rq = cpu_rq(cpu);
+
+       if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) {
+               if (!set_nr_if_polling(rq->idle))
+                       smp_send_reschedule(cpu);
+               else
+                       trace_sched_wake_idle_without_ipi(cpu);
+       }
 }
 
 bool cpus_share_cache(int this_cpu, int that_cpu)
@@ -2527,7 +2554,7 @@ notrace unsigned long get_parent_ip(unsigned long addr)
 #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
                                defined(CONFIG_PREEMPT_TRACER))
 
-void __kprobes preempt_count_add(int val)
+void preempt_count_add(int val)
 {
 #ifdef CONFIG_DEBUG_PREEMPT
        /*
@@ -2553,8 +2580,9 @@ void __kprobes preempt_count_add(int val)
        }
 }
 EXPORT_SYMBOL(preempt_count_add);
+NOKPROBE_SYMBOL(preempt_count_add);
 
-void __kprobes preempt_count_sub(int val)
+void preempt_count_sub(int val)
 {
 #ifdef CONFIG_DEBUG_PREEMPT
        /*
@@ -2575,6 +2603,7 @@ void __kprobes preempt_count_sub(int val)
        __preempt_count_sub(val);
 }
 EXPORT_SYMBOL(preempt_count_sub);
+NOKPROBE_SYMBOL(preempt_count_sub);
 
 #endif
 
@@ -2857,6 +2886,7 @@ asmlinkage __visible void __sched notrace preempt_schedule(void)
                barrier();
        } while (need_resched());
 }
+NOKPROBE_SYMBOL(preempt_schedule);
 EXPORT_SYMBOL(preempt_schedule);
 #endif /* CONFIG_PREEMPT */
 
@@ -4216,7 +4246,7 @@ EXPORT_SYMBOL(yield);
  *     false (0) if we failed to boost the target.
  *     -ESRCH if there's no task to yield to.
  */
-bool __sched yield_to(struct task_struct *p, bool preempt)
+int __sched yield_to(struct task_struct *p, bool preempt)
 {
        struct task_struct *curr = current;
        struct rq *rq, *p_rq;
@@ -5242,14 +5272,13 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                }
 
                /*
-                * Even though we initialize ->power to something semi-sane,
-                * we leave power_orig unset. This allows us to detect if
+                * Even though we initialize ->capacity to something semi-sane,
+                * we leave capacity_orig unset. This allows us to detect if
                 * domain iteration is still funny without causing /0 traps.
                 */
-               if (!group->sgp->power_orig) {
+               if (!group->sgc->capacity_orig) {
                        printk(KERN_CONT "\n");
-                       printk(KERN_ERR "ERROR: domain->cpu_power not "
-                                       "set\n");
+                       printk(KERN_ERR "ERROR: domain->cpu_capacity not set\n");
                        break;
                }
 
@@ -5271,9 +5300,9 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
                cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
 
                printk(KERN_CONT " %s", str);
-               if (group->sgp->power != SCHED_POWER_SCALE) {
-                       printk(KERN_CONT " (cpu_power = %d)",
-                               group->sgp->power);
+               if (group->sgc->capacity != SCHED_CAPACITY_SCALE) {
+                       printk(KERN_CONT " (cpu_capacity = %d)",
+                               group->sgc->capacity);
                }
 
                group = group->next;
@@ -5331,7 +5360,7 @@ static int sd_degenerate(struct sched_domain *sd)
                         SD_BALANCE_NEWIDLE |
                         SD_BALANCE_FORK |
                         SD_BALANCE_EXEC |
-                        SD_SHARE_CPUPOWER |
+                        SD_SHARE_CPUCAPACITY |
                         SD_SHARE_PKG_RESOURCES |
                         SD_SHARE_POWERDOMAIN)) {
                if (sd->groups != sd->groups->next)
@@ -5362,7 +5391,7 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
                                SD_BALANCE_NEWIDLE |
                                SD_BALANCE_FORK |
                                SD_BALANCE_EXEC |
-                               SD_SHARE_CPUPOWER |
+                               SD_SHARE_CPUCAPACITY |
                                SD_SHARE_PKG_RESOURCES |
                                SD_PREFER_SIBLING |
                                SD_SHARE_POWERDOMAIN);
@@ -5487,7 +5516,7 @@ static struct root_domain *alloc_rootdomain(void)
        return rd;
 }
 
-static void free_sched_groups(struct sched_group *sg, int free_sgp)
+static void free_sched_groups(struct sched_group *sg, int free_sgc)
 {
        struct sched_group *tmp, *first;
 
@@ -5498,8 +5527,8 @@ static void free_sched_groups(struct sched_group *sg, int free_sgp)
        do {
                tmp = sg->next;
 
-               if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
-                       kfree(sg->sgp);
+               if (free_sgc && atomic_dec_and_test(&sg->sgc->ref))
+                       kfree(sg->sgc);
 
                kfree(sg);
                sg = tmp;
@@ -5517,7 +5546,7 @@ static void free_sched_domain(struct rcu_head *rcu)
        if (sd->flags & SD_OVERLAP) {
                free_sched_groups(sd->groups, 1);
        } else if (atomic_dec_and_test(&sd->groups->ref)) {
-               kfree(sd->groups->sgp);
+               kfree(sd->groups->sgc);
                kfree(sd->groups);
        }
        kfree(sd);
@@ -5728,17 +5757,17 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
 
                cpumask_or(covered, covered, sg_span);
 
-               sg->sgp = *per_cpu_ptr(sdd->sgp, i);
-               if (atomic_inc_return(&sg->sgp->ref) == 1)
+               sg->sgc = *per_cpu_ptr(sdd->sgc, i);
+               if (atomic_inc_return(&sg->sgc->ref) == 1)
                        build_group_mask(sd, sg);
 
                /*
-                * Initialize sgp->power such that even if we mess up the
+                * Initialize sgc->capacity such that even if we mess up the
                 * domains and no possible iteration will get us here, we won't
                 * die on a /0 trap.
                 */
-               sg->sgp->power = SCHED_POWER_SCALE * cpumask_weight(sg_span);
-               sg->sgp->power_orig = sg->sgp->power;
+               sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span);
+               sg->sgc->capacity_orig = sg->sgc->capacity;
 
                /*
                 * Make sure the first group of this domain contains the
@@ -5776,8 +5805,8 @@ static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
 
        if (sg) {
                *sg = *per_cpu_ptr(sdd->sg, cpu);
-               (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
-               atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
+               (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu);
+               atomic_set(&(*sg)->sgc->ref, 1); /* for claim_allocations */
        }
 
        return cpu;
@@ -5786,7 +5815,7 @@ static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
 /*
  * build_sched_groups will build a circular linked list of the groups
  * covered by the given span, and will set each group's ->cpumask correctly,
- * and ->cpu_power to 0.
+ * and ->cpu_capacity to 0.
  *
  * Assumes the sched_domain tree is fully constructed
  */
@@ -5840,16 +5869,16 @@ build_sched_groups(struct sched_domain *sd, int cpu)
 }
 
 /*
- * Initialize sched groups cpu_power.
+ * Initialize sched groups cpu_capacity.
  *
- * cpu_power indicates the capacity of sched group, which is used while
+ * cpu_capacity indicates the capacity of sched group, which is used while
  * distributing the load between different sched groups in a sched domain.
- * Typically cpu_power for all the groups in a sched domain will be same unless
- * there are asymmetries in the topology. If there are asymmetries, group
- * having more cpu_power will pickup more load compared to the group having
- * less cpu_power.
+ * Typically cpu_capacity for all the groups in a sched domain will be same
+ * unless there are asymmetries in the topology. If there are asymmetries,
+ * group having more cpu_capacity will pickup more load compared to the
+ * group having less cpu_capacity.
  */
-static void init_sched_groups_power(int cpu, struct sched_domain *sd)
+static void init_sched_groups_capacity(int cpu, struct sched_domain *sd)
 {
        struct sched_group *sg = sd->groups;
 
@@ -5863,8 +5892,8 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
        if (cpu != group_balance_cpu(sg))
                return;
 
-       update_group_power(sd, cpu);
-       atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight);
+       update_group_capacity(sd, cpu);
+       atomic_set(&sg->sgc->nr_busy_cpus, sg->group_weight);
 }
 
 /*
@@ -5955,8 +5984,8 @@ static void claim_allocations(int cpu, struct sched_domain *sd)
        if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
                *per_cpu_ptr(sdd->sg, cpu) = NULL;
 
-       if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
-               *per_cpu_ptr(sdd->sgp, cpu) = NULL;
+       if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref))
+               *per_cpu_ptr(sdd->sgc, cpu) = NULL;
 }
 
 #ifdef CONFIG_NUMA
@@ -5969,7 +5998,7 @@ static int sched_domains_curr_level;
 /*
  * SD_flags allowed in topology descriptions.
  *
- * SD_SHARE_CPUPOWER      - describes SMT topologies
+ * SD_SHARE_CPUCAPACITY      - describes SMT topologies
  * SD_SHARE_PKG_RESOURCES - describes shared caches
  * SD_NUMA                - describes NUMA topologies
  * SD_SHARE_POWERDOMAIN   - describes shared power domain
@@ -5978,7 +6007,7 @@ static int sched_domains_curr_level;
  * SD_ASYM_PACKING        - describes SMT quirks
  */
 #define TOPOLOGY_SD_FLAGS              \
-       (SD_SHARE_CPUPOWER |            \
+       (SD_SHARE_CPUCAPACITY |         \
         SD_SHARE_PKG_RESOURCES |       \
         SD_NUMA |                      \
         SD_ASYM_PACKING |              \
@@ -6024,7 +6053,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu)
                                        | 1*SD_BALANCE_FORK
                                        | 0*SD_BALANCE_WAKE
                                        | 1*SD_WAKE_AFFINE
-                                       | 0*SD_SHARE_CPUPOWER
+                                       | 0*SD_SHARE_CPUCAPACITY
                                        | 0*SD_SHARE_PKG_RESOURCES
                                        | 0*SD_SERIALIZE
                                        | 0*SD_PREFER_SIBLING
@@ -6046,7 +6075,7 @@ sd_init(struct sched_domain_topology_level *tl, int cpu)
         * Convert topological properties into behaviour.
         */
 
-       if (sd->flags & SD_SHARE_CPUPOWER) {
+       if (sd->flags & SD_SHARE_CPUCAPACITY) {
                sd->imbalance_pct = 110;
                sd->smt_gain = 1178; /* ~15% */
 
@@ -6358,14 +6387,14 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
                if (!sdd->sg)
                        return -ENOMEM;
 
-               sdd->sgp = alloc_percpu(struct sched_group_power *);
-               if (!sdd->sgp)
+               sdd->sgc = alloc_percpu(struct sched_group_capacity *);
+               if (!sdd->sgc)
                        return -ENOMEM;
 
                for_each_cpu(j, cpu_map) {
                        struct sched_domain *sd;
                        struct sched_group *sg;
-                       struct sched_group_power *sgp;
+                       struct sched_group_capacity *sgc;
 
                        sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
                                        GFP_KERNEL, cpu_to_node(j));
@@ -6383,12 +6412,12 @@ static int __sdt_alloc(const struct cpumask *cpu_map)
 
                        *per_cpu_ptr(sdd->sg, j) = sg;
 
-                       sgp = kzalloc_node(sizeof(struct sched_group_power) + cpumask_size(),
+                       sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(),
                                        GFP_KERNEL, cpu_to_node(j));
-                       if (!sgp)
+                       if (!sgc)
                                return -ENOMEM;
 
-                       *per_cpu_ptr(sdd->sgp, j) = sgp;
+                       *per_cpu_ptr(sdd->sgc, j) = sgc;
                }
        }
 
@@ -6415,15 +6444,15 @@ static void __sdt_free(const struct cpumask *cpu_map)
 
                        if (sdd->sg)
                                kfree(*per_cpu_ptr(sdd->sg, j));
-                       if (sdd->sgp)
-                               kfree(*per_cpu_ptr(sdd->sgp, j));
+                       if (sdd->sgc)
+                               kfree(*per_cpu_ptr(sdd->sgc, j));
                }
                free_percpu(sdd->sd);
                sdd->sd = NULL;
                free_percpu(sdd->sg);
                sdd->sg = NULL;
-               free_percpu(sdd->sgp);
-               sdd->sgp = NULL;
+               free_percpu(sdd->sgc);
+               sdd->sgc = NULL;
        }
 }
 
@@ -6493,14 +6522,14 @@ static int build_sched_domains(const struct cpumask *cpu_map,
                }
        }
 
-       /* Calculate CPU power for physical packages and nodes */
+       /* Calculate CPU capacity for physical packages and nodes */
        for (i = nr_cpumask_bits-1; i >= 0; i--) {
                if (!cpumask_test_cpu(i, cpu_map))
                        continue;
 
                for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
                        claim_allocations(i, sd);
-                       init_sched_groups_power(i, sd);
+                       init_sched_groups_capacity(i, sd);
                }
        }
 
@@ -6943,7 +6972,7 @@ void __init sched_init(void)
 #ifdef CONFIG_SMP
                rq->sd = NULL;
                rq->rd = NULL;
-               rq->cpu_power = SCHED_POWER_SCALE;
+               rq->cpu_capacity = SCHED_CAPACITY_SCALE;
                rq->post_schedule = 0;
                rq->active_balance = 0;
                rq->next_balance = jiffies;