]> git.kernelconcepts.de Git - karo-tx-linux.git/commitdiff
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
authorLinus Torvalds <torvalds@linux-foundation.org>
Fri, 13 Jun 2014 02:42:15 +0000 (19:42 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 13 Jun 2014 02:42:15 +0000 (19:42 -0700)
Pull more scheduler updates from Ingo Molnar:
 "Second round of scheduler changes:
   - try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
   - continued power scheduling cleanups and refactorings, from Nicolas
     Pitre
   - misc fixes and enhancements"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Delete extraneous extern for to_ratio()
  sched/idle: Optimize try-to-wake-up IPI
  sched/idle: Simplify wake_up_idle_cpu()
  sched/idle: Clear polling before descheduling the idle thread
  sched, trace: Add a tracepoint for IPI-less remote wakeups
  cpuidle: Set polling in poll_idle
  sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
  sched: Rename capacity related flags
  sched: Final power vs. capacity cleanups
  sched: Remove remaining dubious usage of "power"
  sched: Let 'struct sched_group_power' care about CPU capacity
  sched/fair: Disambiguate existing/remaining "capacity" usage
  sched/fair: Change "has_capacity" to "has_free_capacity"
  sched/fair: Remove "power" from 'struct numa_stats'
  sched: Fix signedness bug in yield_to()
  sched/fair: Use time_after() in record_wakee()
  sched/balancing: Reduce the rate of needless idle load balancing
  sched/fair: Fix unlocked reads of some cfs_b->quota/period

14 files changed:
arch/arm/kernel/topology.c
arch/powerpc/kernel/smp.c
drivers/cpuidle/driver.c
include/linux/kvm_host.h
include/linux/sched.h
include/trace/events/sched.h
kernel/sched/core.c
kernel/sched/deadline.c
kernel/sched/fair.c
kernel/sched/features.h
kernel/sched/idle.c
kernel/sched/rt.c
kernel/sched/sched.h
virt/kvm/kvm_main.c

index 3997c411c1403659123d188c1c0750c58f59af3f..9d853189028bb0c79ad72557b018c12d5416aa67 100644 (file)
 #include <asm/topology.h>
 
 /*
- * cpu power scale management
+ * cpu capacity scale management
  */
 
 /*
- * cpu power table
+ * cpu capacity table
  * This per cpu data structure describes the relative capacity of each core.
  * On a heteregenous system, cores don't have the same computation capacity
- * and we reflect that difference in the cpu_power field so the scheduler can
- * take this difference into account during load balance. A per cpu structure
- * is preferred because each CPU updates its own cpu_power field during the
- * load balance except for idle cores. One idle core is selected to run the
- * rebalance_domains for all idle cores and the cpu_power can be updated
- * during this sequence.
+ * and we reflect that difference in the cpu_capacity field so the scheduler
+ * can take this difference into account during load balance. A per cpu
+ * structure is preferred because each CPU updates its own cpu_capacity field
+ * during the load balance except for idle cores. One idle core is selected
+ * to run the rebalance_domains for all idle cores and the cpu_capacity can be
+ * updated during this sequence.
  */
 static DEFINE_PER_CPU(unsigned long, cpu_scale);
 
-unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu)
+unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
 {
        return per_cpu(cpu_scale, cpu);
 }
 
-static void set_power_scale(unsigned int cpu, unsigned long power)
+static void set_capacity_scale(unsigned int cpu, unsigned long capacity)
 {
-       per_cpu(cpu_scale, cpu) = power;
+       per_cpu(cpu_scale, cpu) = capacity;
 }
 
 #ifdef CONFIG_OF
@@ -62,11 +62,11 @@ struct cpu_efficiency {
  * Table of relative efficiency of each processors
  * The efficiency value must fit in 20bit and the final
  * cpu_scale value must be in the range
- *   0 < cpu_scale < 3*SCHED_POWER_SCALE/2
+ *   0 < cpu_scale < 3*SCHED_CAPACITY_SCALE/2
  * in order to return at most 1 when DIV_ROUND_CLOSEST
  * is used to compute the capacity of a CPU.
  * Processors that are not defined in the table,
- * use the default SCHED_POWER_SCALE value for cpu_scale.
+ * use the default SCHED_CAPACITY_SCALE value for cpu_scale.
  */
 static const struct cpu_efficiency table_efficiency[] = {
        {"arm,cortex-a15", 3891},
@@ -83,9 +83,9 @@ static unsigned long middle_capacity = 1;
  * Iterate all CPUs' descriptor in DT and compute the efficiency
  * (as per table_efficiency). Also calculate a middle efficiency
  * as close as possible to  (max{eff_i} - min{eff_i}) / 2
- * This is later used to scale the cpu_power field such that an
- * 'average' CPU is of middle power. Also see the comments near
- * table_efficiency[] and update_cpu_power().
+ * This is later used to scale the cpu_capacity field such that an
+ * 'average' CPU is of middle capacity. Also see the comments near
+ * table_efficiency[] and update_cpu_capacity().
  */
 static void __init parse_dt_topology(void)
 {
@@ -141,15 +141,15 @@ static void __init parse_dt_topology(void)
         * cpu_scale because all CPUs have the same capacity. Otherwise, we
         * compute a middle_capacity factor that will ensure that the capacity
         * of an 'average' CPU of the system will be as close as possible to
-        * SCHED_POWER_SCALE, which is the default value, but with the
+        * SCHED_CAPACITY_SCALE, which is the default value, but with the
         * constraint explained near table_efficiency[].
         */
        if (4*max_capacity < (3*(max_capacity + min_capacity)))
                middle_capacity = (min_capacity + max_capacity)
-                               >> (SCHED_POWER_SHIFT+1);
+                               >> (SCHED_CAPACITY_SHIFT+1);
        else
                middle_capacity = ((max_capacity / 3)
-                               >> (SCHED_POWER_SHIFT-1)) + 1;
+                               >> (SCHED_CAPACITY_SHIFT-1)) + 1;
 
 }
 
@@ -158,20 +158,20 @@ static void __init parse_dt_topology(void)
  * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the
  * function returns directly for SMP system.
  */
-static void update_cpu_power(unsigned int cpu)
+static void update_cpu_capacity(unsigned int cpu)
 {
        if (!cpu_capacity(cpu))
                return;
 
-       set_power_scale(cpu, cpu_capacity(cpu) / middle_capacity);
+       set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity);
 
-       printk(KERN_INFO "CPU%u: update cpu_power %lu\n",
-               cpu, arch_scale_freq_power(NULL, cpu));
+       printk(KERN_INFO "CPU%u: update cpu_capacity %lu\n",
+               cpu, arch_scale_freq_capacity(NULL, cpu));
 }
 
 #else
 static inline void parse_dt_topology(void) {}
-static inline void update_cpu_power(unsigned int cpuid) {}
+static inline void update_cpu_capacity(unsigned int cpuid) {}
 #endif
 
  /*
@@ -267,7 +267,7 @@ void store_cpu_topology(unsigned int cpuid)
 
        update_siblings_masks(cpuid);
 
-       update_cpu_power(cpuid);
+       update_cpu_capacity(cpuid);
 
        printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
                cpuid, cpu_topology[cpuid].thread_id,
@@ -297,7 +297,7 @@ void __init init_cpu_topology(void)
 {
        unsigned int cpu;
 
-       /* init core mask and power*/
+       /* init core mask and capacity */
        for_each_possible_cpu(cpu) {
                struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]);
 
@@ -307,7 +307,7 @@ void __init init_cpu_topology(void)
                cpumask_clear(&cpu_topo->core_sibling);
                cpumask_clear(&cpu_topo->thread_sibling);
 
-               set_power_scale(cpu, SCHED_POWER_SCALE);
+               set_capacity_scale(cpu, SCHED_CAPACITY_SCALE);
        }
        smp_wmb();
 
index 7753af2d261381bcc21bf3e21f8ee4f4880847e9..51a3ff78838aaf1eb6726e92cb871c128221eb2e 100644 (file)
@@ -749,7 +749,7 @@ int setup_profiling_timer(unsigned int multiplier)
 /* cpumask of CPUs with asymetric SMT dependancy */
 static const int powerpc_smt_flags(void)
 {
-       int flags = SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES;
+       int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 
        if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
                printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
index 136d6a283e0a3818846eab4e78e7e9245b7d6f07..9634f20e392611b32349aaa348aa3980f2344ecd 100644 (file)
@@ -187,8 +187,11 @@ static int poll_idle(struct cpuidle_device *dev,
 
        t1 = ktime_get();
        local_irq_enable();
-       while (!need_resched())
-               cpu_relax();
+       if (!current_set_polling_and_test()) {
+               while (!need_resched())
+                       cpu_relax();
+       }
+       current_clr_polling();
 
        t2 = ktime_get();
        diff = ktime_to_us(ktime_sub(t2, t1));
index 970c68197c698898df483198995d9a0c558c0770..ec4e3bd83d474e581bb3e4607c3c9c5f4e5319c8 100644 (file)
@@ -586,7 +586,7 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
 
 void kvm_vcpu_block(struct kvm_vcpu *vcpu);
 void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
-bool kvm_vcpu_yield_to(struct kvm_vcpu *target);
+int kvm_vcpu_yield_to(struct kvm_vcpu *target);
 void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
 void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
 void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);
index b8a98427f964cd05102621821e2f9ef926686004..306f4f0c987a006f43f520413f7de3a780f98a23 100644 (file)
@@ -847,10 +847,10 @@ enum cpu_idle_type {
 };
 
 /*
- * Increase resolution of cpu_power calculations
+ * Increase resolution of cpu_capacity calculations
  */
-#define SCHED_POWER_SHIFT      10
-#define SCHED_POWER_SCALE      (1L << SCHED_POWER_SHIFT)
+#define SCHED_CAPACITY_SHIFT   10
+#define SCHED_CAPACITY_SCALE   (1L << SCHED_CAPACITY_SHIFT)
 
 /*
  * sched-domains (multiprocessor balancing) declarations:
@@ -862,7 +862,7 @@ enum cpu_idle_type {
 #define SD_BALANCE_FORK                0x0008  /* Balance on fork, clone */
 #define SD_BALANCE_WAKE                0x0010  /* Balance on wakeup */
 #define SD_WAKE_AFFINE         0x0020  /* Wake task to waking CPU */
-#define SD_SHARE_CPUPOWER      0x0080  /* Domain members share cpu power */
+#define SD_SHARE_CPUCAPACITY   0x0080  /* Domain members share cpu power */
 #define SD_SHARE_POWERDOMAIN   0x0100  /* Domain members share power domain */
 #define SD_SHARE_PKG_RESOURCES 0x0200  /* Domain members share cpu pkg resources */
 #define SD_SERIALIZE           0x0400  /* Only a single load balancing instance */
@@ -874,7 +874,7 @@ enum cpu_idle_type {
 #ifdef CONFIG_SCHED_SMT
 static inline const int cpu_smt_flags(void)
 {
-       return SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES;
+       return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES;
 }
 #endif
 
@@ -1006,7 +1006,7 @@ typedef const int (*sched_domain_flags_f)(void);
 struct sd_data {
        struct sched_domain **__percpu sd;
        struct sched_group **__percpu sg;
-       struct sched_group_power **__percpu sgp;
+       struct sched_group_capacity **__percpu sgc;
 };
 
 struct sched_domain_topology_level {
@@ -2173,7 +2173,7 @@ static inline void sched_autogroup_fork(struct signal_struct *sig) { }
 static inline void sched_autogroup_exit(struct signal_struct *sig) { }
 #endif
 
-extern bool yield_to(struct task_struct *p, bool preempt);
+extern int yield_to(struct task_struct *p, bool preempt);
 extern void set_user_nice(struct task_struct *p, long nice);
 extern int task_prio(const struct task_struct *p);
 /**
index 67e1bbf836954dbc486d1d7debb3a2bfa3cfd3d1..0a68d5ae584e9dfada372fdae49c5d0934176402 100644 (file)
@@ -530,6 +530,26 @@ TRACE_EVENT(sched_swap_numa,
                        __entry->dst_pid, __entry->dst_tgid, __entry->dst_ngid,
                        __entry->dst_cpu, __entry->dst_nid)
 );
+
+/*
+ * Tracepoint for waking a polling cpu without an IPI.
+ */
+TRACE_EVENT(sched_wake_idle_without_ipi,
+
+       TP_PROTO(int cpu),
+
+       TP_ARGS(cpu),
+
+       TP_STRUCT__entry(
+               __field(        int,    cpu     )
+       ),
+
+       TP_fast_assign(
+               __entry->cpu    = cpu;
+       ),
+
+       TP_printk("cpu=%d", __entry->cpu)
+);
 #endif /* _TRACE_SCHED_H */
 
 /* This part must be outside protection */
index 4f611561ba4cc59204522a67643ded9275b0bc37..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)
@@ -4219,7 +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;
@@ -5245,14 +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;
                }
 
@@ -5274,9 +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;
@@ -5334,7 +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)
@@ -5365,7 +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);
@@ -5490,7 +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;
 
@@ -5501,8 +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;
@@ -5520,7 +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);
@@ -5731,17 +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
@@ -5779,8 +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;
@@ -5789,7 +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
  */
@@ -5843,16 +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;
 
@@ -5866,8 +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);
 }
 
 /*
@@ -5958,8 +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
@@ -5972,7 +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
@@ -5981,7 +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 |              \
@@ -6027,7 +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
@@ -6049,7 +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% */
 
@@ -6361,14 +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));
@@ -6386,12 +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;
                }
        }
 
@@ -6418,15 +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;
        }
 }
 
@@ -6496,14 +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);
                }
        }
 
@@ -6946,7 +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;
index 2b8cbf09d1a4add6fe837be0080a71a35f145164..fc4f98b1258f66cbbf3cf1fc1082cb909c0f1144 100644 (file)
@@ -57,8 +57,6 @@ void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime)
        dl_b->dl_runtime = runtime;
 }
 
-extern unsigned long to_ratio(u64 period, u64 runtime);
-
 void init_dl_bw(struct dl_bw *dl_b)
 {
        raw_spin_lock_init(&dl_b->lock);
index 9855e87d671a54982238d325f014162327a974e8..fea7d3335e1fdf3502fc72f5d64b9181bc7e4243 100644 (file)
@@ -1017,7 +1017,7 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
 static unsigned long weighted_cpuload(const int cpu);
 static unsigned long source_load(int cpu, int type);
 static unsigned long target_load(int cpu, int type);
-static unsigned long power_of(int cpu);
+static unsigned long capacity_of(int cpu);
 static long effective_load(struct task_group *tg, int cpu, long wl, long wg);
 
 /* Cached statistics for all CPUs within a node */
@@ -1026,11 +1026,11 @@ struct numa_stats {
        unsigned long load;
 
        /* Total compute capacity of CPUs on a node */
-       unsigned long power;
+       unsigned long compute_capacity;
 
        /* Approximate capacity in terms of runnable tasks on a node */
-       unsigned long capacity;
-       int has_capacity;
+       unsigned long task_capacity;
+       int has_free_capacity;
 };
 
 /*
@@ -1046,7 +1046,7 @@ static void update_numa_stats(struct numa_stats *ns, int nid)
 
                ns->nr_running += rq->nr_running;
                ns->load += weighted_cpuload(cpu);
-               ns->power += power_of(cpu);
+               ns->compute_capacity += capacity_of(cpu);
 
                cpus++;
        }
@@ -1056,15 +1056,16 @@ static void update_numa_stats(struct numa_stats *ns, int nid)
         * the @ns structure is NULL'ed and task_numa_compare() will
         * not find this node attractive.
         *
-        * We'll either bail at !has_capacity, or we'll detect a huge imbalance
-        * and bail there.
+        * We'll either bail at !has_free_capacity, or we'll detect a huge
+        * imbalance and bail there.
         */
        if (!cpus)
                return;
 
-       ns->load = (ns->load * SCHED_POWER_SCALE) / ns->power;
-       ns->capacity = DIV_ROUND_CLOSEST(ns->power, SCHED_POWER_SCALE);
-       ns->has_capacity = (ns->nr_running < ns->capacity);
+       ns->load = (ns->load * SCHED_CAPACITY_SCALE) / ns->compute_capacity;
+       ns->task_capacity =
+               DIV_ROUND_CLOSEST(ns->compute_capacity, SCHED_CAPACITY_SCALE);
+       ns->has_free_capacity = (ns->nr_running < ns->task_capacity);
 }
 
 struct task_numa_env {
@@ -1195,8 +1196,8 @@ static void task_numa_compare(struct task_numa_env *env,
 
        if (!cur) {
                /* Is there capacity at our destination? */
-               if (env->src_stats.has_capacity &&
-                   !env->dst_stats.has_capacity)
+               if (env->src_stats.has_free_capacity &&
+                   !env->dst_stats.has_free_capacity)
                        goto unlock;
 
                goto balance;
@@ -1213,7 +1214,7 @@ balance:
        orig_dst_load = env->dst_stats.load;
        orig_src_load = env->src_stats.load;
 
-       /* XXX missing power terms */
+       /* XXX missing capacity terms */
        load = task_h_load(env->p);
        dst_load = orig_dst_load + load;
        src_load = orig_src_load - load;
@@ -1301,8 +1302,8 @@ static int task_numa_migrate(struct task_struct *p)
        groupimp = group_weight(p, env.dst_nid) - groupweight;
        update_numa_stats(&env.dst_stats, env.dst_nid);
 
-       /* If the preferred nid has capacity, try to use it. */
-       if (env.dst_stats.has_capacity)
+       /* If the preferred nid has free capacity, try to use it. */
+       if (env.dst_stats.has_free_capacity)
                task_numa_find_cpu(&env, taskimp, groupimp);
 
        /* No space available on the preferred nid. Look elsewhere. */
@@ -3225,10 +3226,12 @@ static void expire_cfs_rq_runtime(struct cfs_rq *cfs_rq)
         * has not truly expired.
         *
         * Fortunately we can check determine whether this the case by checking
-        * whether the global deadline has advanced.
+        * whether the global deadline has advanced. It is valid to compare
+        * cfs_b->runtime_expires without any locks since we only care about
+        * exact equality, so a partial write will still work.
         */
 
-       if ((s64)(cfs_rq->runtime_expires - cfs_b->runtime_expires) >= 0) {
+       if (cfs_rq->runtime_expires != cfs_b->runtime_expires) {
                /* extend local deadline, drift is bounded above by 2 ticks */
                cfs_rq->runtime_expires += TICK_NSEC;
        } else {
@@ -3457,21 +3460,21 @@ next:
 static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
 {
        u64 runtime, runtime_expires;
-       int idle = 1, throttled;
+       int throttled;
 
-       raw_spin_lock(&cfs_b->lock);
        /* no need to continue the timer with no bandwidth constraint */
        if (cfs_b->quota == RUNTIME_INF)
-               goto out_unlock;
+               goto out_deactivate;
 
        throttled = !list_empty(&cfs_b->throttled_cfs_rq);
-       /* idle depends on !throttled (for the case of a large deficit) */
-       idle = cfs_b->idle && !throttled;
        cfs_b->nr_periods += overrun;
 
-       /* if we're going inactive then everything else can be deferred */
-       if (idle)
-               goto out_unlock;
+       /*
+        * idle depends on !throttled (for the case of a large deficit), and if
+        * we're going inactive then everything else can be deferred
+        */
+       if (cfs_b->idle && !throttled)
+               goto out_deactivate;
 
        /*
         * if we have relooped after returning idle once, we need to update our
@@ -3485,7 +3488,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
        if (!throttled) {
                /* mark as potentially idle for the upcoming period */
                cfs_b->idle = 1;
-               goto out_unlock;
+               return 0;
        }
 
        /* account preceding periods in which throttling occurred */
@@ -3525,12 +3528,12 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
         * timer to remain active while there are any throttled entities.)
         */
        cfs_b->idle = 0;
-out_unlock:
-       if (idle)
-               cfs_b->timer_active = 0;
-       raw_spin_unlock(&cfs_b->lock);
 
-       return idle;
+       return 0;
+
+out_deactivate:
+       cfs_b->timer_active = 0;
+       return 1;
 }
 
 /* a cfs_rq won't donate quota below this amount */
@@ -3707,6 +3710,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
        int overrun;
        int idle = 0;
 
+       raw_spin_lock(&cfs_b->lock);
        for (;;) {
                now = hrtimer_cb_get_time(timer);
                overrun = hrtimer_forward(timer, now, cfs_b->period);
@@ -3716,6 +3720,7 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
 
                idle = do_sched_cfs_period_timer(cfs_b, overrun);
        }
+       raw_spin_unlock(&cfs_b->lock);
 
        return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
 }
@@ -3775,8 +3780,6 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
        struct cfs_rq *cfs_rq;
 
        for_each_leaf_cfs_rq(rq, cfs_rq) {
-               struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
-
                if (!cfs_rq->runtime_enabled)
                        continue;
 
@@ -3784,7 +3787,7 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
                 * clock_task is not advancing so we just need to make sure
                 * there's some valid quota amount
                 */
-               cfs_rq->runtime_remaining = cfs_b->quota;
+               cfs_rq->runtime_remaining = 1;
                if (cfs_rq_throttled(cfs_rq))
                        unthrottle_cfs_rq(cfs_rq);
        }
@@ -4041,9 +4044,9 @@ static unsigned long target_load(int cpu, int type)
        return max(rq->cpu_load[type-1], total);
 }
 
-static unsigned long power_of(int cpu)
+static unsigned long capacity_of(int cpu)
 {
-       return cpu_rq(cpu)->cpu_power;
+       return cpu_rq(cpu)->cpu_capacity;
 }
 
 static unsigned long cpu_avg_load_per_task(int cpu)
@@ -4065,7 +4068,7 @@ static void record_wakee(struct task_struct *p)
         * about the boundary, really active task won't care
         * about the loss.
         */
-       if (jiffies > current->wakee_flip_decay_ts + HZ) {
+       if (time_after(jiffies, current->wakee_flip_decay_ts + HZ)) {
                current->wakee_flips >>= 1;
                current->wakee_flip_decay_ts = jiffies;
        }
@@ -4286,12 +4289,12 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
                s64 this_eff_load, prev_eff_load;
 
                this_eff_load = 100;
-               this_eff_load *= power_of(prev_cpu);
+               this_eff_load *= capacity_of(prev_cpu);
                this_eff_load *= this_load +
                        effective_load(tg, this_cpu, weight, weight);
 
                prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
-               prev_eff_load *= power_of(this_cpu);
+               prev_eff_load *= capacity_of(this_cpu);
                prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight);
 
                balanced = this_eff_load <= prev_eff_load;
@@ -4367,8 +4370,8 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
                        avg_load += load;
                }
 
-               /* Adjust by relative CPU power of the group */
-               avg_load = (avg_load * SCHED_POWER_SCALE) / group->sgp->power;
+               /* Adjust by relative CPU capacity of the group */
+               avg_load = (avg_load * SCHED_CAPACITY_SCALE) / group->sgc->capacity;
 
                if (local_group) {
                        this_load = avg_load;
@@ -4948,14 +4951,14 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preemp
  *
  *   W'_i,n = (2^n - 1) / 2^n * W_i,n + 1 / 2^n * W_i,0               (3)
  *
- * P_i is the cpu power (or compute capacity) of cpu i, typically it is the
+ * C_i is the compute capacity of cpu i, typically it is the
  * fraction of 'recent' time available for SCHED_OTHER task execution. But it
  * can also include other factors [XXX].
  *
  * To achieve this balance we define a measure of imbalance which follows
  * directly from (1):
  *
- *   imb_i,j = max{ avg(W/P), W_i/P_i } - min{ avg(W/P), W_j/P_j }    (4)
+ *   imb_i,j = max{ avg(W/C), W_i/C_i } - min{ avg(W/C), W_j/C_j }    (4)
  *
  * We them move tasks around to minimize the imbalance. In the continuous
  * function space it is obvious this converges, in the discrete case we get
@@ -5530,13 +5533,13 @@ struct sg_lb_stats {
        unsigned long group_load; /* Total load over the CPUs of the group */
        unsigned long sum_weighted_load; /* Weighted load of group's tasks */
        unsigned long load_per_task;
-       unsigned long group_power;
+       unsigned long group_capacity;
        unsigned int sum_nr_running; /* Nr tasks running in the group */
-       unsigned int group_capacity;
+       unsigned int group_capacity_factor;
        unsigned int idle_cpus;
        unsigned int group_weight;
        int group_imb; /* Is there an imbalance in the group ? */
-       int group_has_capacity; /* Is there extra capacity in the group? */
+       int group_has_free_capacity;
 #ifdef CONFIG_NUMA_BALANCING
        unsigned int nr_numa_running;
        unsigned int nr_preferred_running;
@@ -5551,7 +5554,7 @@ struct sd_lb_stats {
        struct sched_group *busiest;    /* Busiest group in this sd */
        struct sched_group *local;      /* Local group in this sd */
        unsigned long total_load;       /* Total load of all groups in sd */
-       unsigned long total_pwr;        /* Total power of all groups in sd */
+       unsigned long total_capacity;   /* Total capacity of all groups in sd */
        unsigned long avg_load; /* Average load across all groups in sd */
 
        struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */
@@ -5570,7 +5573,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
                .busiest = NULL,
                .local = NULL,
                .total_load = 0UL,
-               .total_pwr = 0UL,
+               .total_capacity = 0UL,
                .busiest_stat = {
                        .avg_load = 0UL,
                },
@@ -5605,17 +5608,17 @@ static inline int get_sd_load_idx(struct sched_domain *sd,
        return load_idx;
 }
 
-static unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
+static unsigned long default_scale_capacity(struct sched_domain *sd, int cpu)
 {
-       return SCHED_POWER_SCALE;
+       return SCHED_CAPACITY_SCALE;
 }
 
-unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu)
+unsigned long __weak arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
 {
-       return default_scale_freq_power(sd, cpu);
+       return default_scale_capacity(sd, cpu);
 }
 
-static unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
+static unsigned long default_scale_smt_capacity(struct sched_domain *sd, int cpu)
 {
        unsigned long weight = sd->span_weight;
        unsigned long smt_gain = sd->smt_gain;
@@ -5625,12 +5628,12 @@ static unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
        return smt_gain;
 }
 
-unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
+unsigned long __weak arch_scale_smt_capacity(struct sched_domain *sd, int cpu)
 {
-       return default_scale_smt_power(sd, cpu);
+       return default_scale_smt_capacity(sd, cpu);
 }
 
-static unsigned long scale_rt_power(int cpu)
+static unsigned long scale_rt_capacity(int cpu)
 {
        struct rq *rq = cpu_rq(cpu);
        u64 total, available, age_stamp, avg;
@@ -5650,71 +5653,71 @@ static unsigned long scale_rt_power(int cpu)
        total = sched_avg_period() + delta;
 
        if (unlikely(total < avg)) {
-               /* Ensures that power won't end up being negative */
+               /* Ensures that capacity won't end up being negative */
                available = 0;
        } else {
                available = total - avg;
        }
 
-       if (unlikely((s64)total < SCHED_POWER_SCALE))
-               total = SCHED_POWER_SCALE;
+       if (unlikely((s64)total < SCHED_CAPACITY_SCALE))
+               total = SCHED_CAPACITY_SCALE;
 
-       total >>= SCHED_POWER_SHIFT;
+       total >>= SCHED_CAPACITY_SHIFT;
 
        return div_u64(available, total);
 }
 
-static void update_cpu_power(struct sched_domain *sd, int cpu)
+static void update_cpu_capacity(struct sched_domain *sd, int cpu)
 {
        unsigned long weight = sd->span_weight;
-       unsigned long power = SCHED_POWER_SCALE;
+       unsigned long capacity = SCHED_CAPACITY_SCALE;
        struct sched_group *sdg = sd->groups;
 
-       if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
-               if (sched_feat(ARCH_POWER))
-                       power *= arch_scale_smt_power(sd, cpu);
+       if ((sd->flags & SD_SHARE_CPUCAPACITY) && weight > 1) {
+               if (sched_feat(ARCH_CAPACITY))
+                       capacity *= arch_scale_smt_capacity(sd, cpu);
                else
-                       power *= default_scale_smt_power(sd, cpu);
+                       capacity *= default_scale_smt_capacity(sd, cpu);
 
-               power >>= SCHED_POWER_SHIFT;
+               capacity >>= SCHED_CAPACITY_SHIFT;
        }
 
-       sdg->sgp->power_orig = power;
+       sdg->sgc->capacity_orig = capacity;
 
-       if (sched_feat(ARCH_POWER))
-               power *= arch_scale_freq_power(sd, cpu);
+       if (sched_feat(ARCH_CAPACITY))
+               capacity *= arch_scale_freq_capacity(sd, cpu);
        else
-               power *= default_scale_freq_power(sd, cpu);
+               capacity *= default_scale_capacity(sd, cpu);
 
-       power >>= SCHED_POWER_SHIFT;
+       capacity >>= SCHED_CAPACITY_SHIFT;
 
-       power *= scale_rt_power(cpu);
-       power >>= SCHED_POWER_SHIFT;
+       capacity *= scale_rt_capacity(cpu);
+       capacity >>= SCHED_CAPACITY_SHIFT;
 
-       if (!power)
-               power = 1;
+       if (!capacity)
+               capacity = 1;
 
-       cpu_rq(cpu)->cpu_power = power;
-       sdg->sgp->power = power;
+       cpu_rq(cpu)->cpu_capacity = capacity;
+       sdg->sgc->capacity = capacity;
 }
 
-void update_group_power(struct sched_domain *sd, int cpu)
+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 power, power_orig;
+       unsigned long capacity, capacity_orig;
        unsigned long interval;
 
        interval = msecs_to_jiffies(sd->balance_interval);
        interval = clamp(interval, 1UL, max_load_balance_interval);
-       sdg->sgp->next_update = jiffies + interval;
+       sdg->sgc->next_update = jiffies + interval;
 
        if (!child) {
-               update_cpu_power(sd, cpu);
+               update_cpu_capacity(sd, cpu);
                return;
        }
 
-       power_orig = power = 0;
+       capacity_orig = capacity = 0;
 
        if (child->flags & SD_OVERLAP) {
                /*
@@ -5723,31 +5726,31 @@ void update_group_power(struct sched_domain *sd, int cpu)
                 */
 
                for_each_cpu(cpu, sched_group_cpus(sdg)) {
-                       struct sched_group_power *sgp;
+                       struct sched_group_capacity *sgc;
                        struct rq *rq = cpu_rq(cpu);
 
                        /*
-                        * build_sched_domains() -> init_sched_groups_power()
+                        * build_sched_domains() -> init_sched_groups_capacity()
                         * gets here before we've attached the domains to the
                         * runqueues.
                         *
-                        * Use power_of(), which is set irrespective of domains
-                        * in update_cpu_power().
+                        * Use capacity_of(), which is set irrespective of domains
+                        * in update_cpu_capacity().
                         *
-                        * This avoids power/power_orig from being 0 and
+                        * This avoids capacity/capacity_orig from being 0 and
                         * causing divide-by-zero issues on boot.
                         *
-                        * Runtime updates will correct power_orig.
+                        * Runtime updates will correct capacity_orig.
                         */
                        if (unlikely(!rq->sd)) {
-                               power_orig += power_of(cpu);
-                               power += power_of(cpu);
+                               capacity_orig += capacity_of(cpu);
+                               capacity += capacity_of(cpu);
                                continue;
                        }
 
-                       sgp = rq->sd->groups->sgp;
-                       power_orig += sgp->power_orig;
-                       power += sgp->power;
+                       sgc = rq->sd->groups->sgc;
+                       capacity_orig += sgc->capacity_orig;
+                       capacity += sgc->capacity;
                }
        } else  {
                /*
@@ -5757,14 +5760,14 @@ void update_group_power(struct sched_domain *sd, int cpu)
 
                group = child->groups;
                do {
-                       power_orig += group->sgp->power_orig;
-                       power += group->sgp->power;
+                       capacity_orig += group->sgc->capacity_orig;
+                       capacity += group->sgc->capacity;
                        group = group->next;
                } while (group != child->groups);
        }
 
-       sdg->sgp->power_orig = power_orig;
-       sdg->sgp->power = power;
+       sdg->sgc->capacity_orig = capacity_orig;
+       sdg->sgc->capacity = capacity;
 }
 
 /*
@@ -5778,15 +5781,15 @@ static inline int
 fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
 {
        /*
-        * Only siblings can have significantly less than SCHED_POWER_SCALE
+        * Only siblings can have significantly less than SCHED_CAPACITY_SCALE
         */
-       if (!(sd->flags & SD_SHARE_CPUPOWER))
+       if (!(sd->flags & SD_SHARE_CPUCAPACITY))
                return 0;
 
        /*
-        * If ~90% of the cpu_power is still there, we're good.
+        * If ~90% of the cpu_capacity is still there, we're good.
         */
-       if (group->sgp->power * 32 > group->sgp->power_orig * 29)
+       if (group->sgc->capacity * 32 > group->sgc->capacity_orig * 29)
                return 1;
 
        return 0;
@@ -5823,34 +5826,35 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
 
 static inline int sg_imbalanced(struct sched_group *group)
 {
-       return group->sgp->imbalance;
+       return group->sgc->imbalance;
 }
 
 /*
- * Compute the group capacity.
+ * Compute the group capacity factor.
  *
- * Avoid the issue where N*frac(smt_power) >= 1 creates 'phantom' cores by
+ * Avoid the issue where N*frac(smt_capacity) >= 1 creates 'phantom' cores by
  * first dividing out the smt factor and computing the actual number of cores
- * and limit power unit capacity with that.
+ * and limit unit capacity with that.
  */
-static inline int sg_capacity(struct lb_env *env, struct sched_group *group)
+static inline int sg_capacity_factor(struct lb_env *env, struct sched_group *group)
 {
-       unsigned int capacity, smt, cpus;
-       unsigned int power, power_orig;
+       unsigned int capacity_factor, smt, cpus;
+       unsigned int capacity, capacity_orig;
 
-       power = group->sgp->power;
-       power_orig = group->sgp->power_orig;
+       capacity = group->sgc->capacity;
+       capacity_orig = group->sgc->capacity_orig;
        cpus = group->group_weight;
 
-       /* smt := ceil(cpus / power), assumes: 1 < smt_power < 2 */
-       smt = DIV_ROUND_UP(SCHED_POWER_SCALE * cpus, power_orig);
-       capacity = cpus / smt; /* cores */
+       /* smt := ceil(cpus / capacity), assumes: 1 < smt_capacity < 2 */
+       smt = DIV_ROUND_UP(SCHED_CAPACITY_SCALE * cpus, capacity_orig);
+       capacity_factor = cpus / smt; /* cores */
 
-       capacity = min_t(unsigned, capacity, DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE));
-       if (!capacity)
-               capacity = fix_small_capacity(env->sd, group);
+       capacity_factor = min_t(unsigned,
+               capacity_factor, DIV_ROUND_CLOSEST(capacity, SCHED_CAPACITY_SCALE));
+       if (!capacity_factor)
+               capacity_factor = fix_small_capacity(env->sd, group);
 
-       return capacity;
+       return capacity_factor;
 }
 
 /**
@@ -5890,9 +5894,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
                        sgs->idle_cpus++;
        }
 
-       /* Adjust by relative CPU power of the group */
-       sgs->group_power = group->sgp->power;
-       sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / sgs->group_power;
+       /* Adjust by relative CPU capacity of the group */
+       sgs->group_capacity = group->sgc->capacity;
+       sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) / sgs->group_capacity;
 
        if (sgs->sum_nr_running)
                sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
@@ -5900,10 +5904,10 @@ static inline void update_sg_lb_stats(struct lb_env *env,
        sgs->group_weight = group->group_weight;
 
        sgs->group_imb = sg_imbalanced(group);
-       sgs->group_capacity = sg_capacity(env, group);
+       sgs->group_capacity_factor = sg_capacity_factor(env, group);
 
-       if (sgs->group_capacity > sgs->sum_nr_running)
-               sgs->group_has_capacity = 1;
+       if (sgs->group_capacity_factor > sgs->sum_nr_running)
+               sgs->group_has_free_capacity = 1;
 }
 
 /**
@@ -5927,7 +5931,7 @@ static bool update_sd_pick_busiest(struct lb_env *env,
        if (sgs->avg_load <= sds->busiest_stat.avg_load)
                return false;
 
-       if (sgs->sum_nr_running > sgs->group_capacity)
+       if (sgs->sum_nr_running > sgs->group_capacity_factor)
                return true;
 
        if (sgs->group_imb)
@@ -6007,8 +6011,8 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
                        sgs = &sds->local_stat;
 
                        if (env->idle != CPU_NEWLY_IDLE ||
-                           time_after_eq(jiffies, sg->sgp->next_update))
-                               update_group_power(env->sd, env->dst_cpu);
+                           time_after_eq(jiffies, sg->sgc->next_update))
+                               update_group_capacity(env->sd, env->dst_cpu);
                }
 
                update_sg_lb_stats(env, sg, load_idx, local_group, sgs);
@@ -6018,17 +6022,17 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
 
                /*
                 * In case the child domain prefers tasks go to siblings
-                * first, lower the sg capacity to one so that we'll try
+                * first, lower the sg capacity factor to one so that we'll try
                 * and move all the excess tasks away. We lower the capacity
                 * of a group only if the local group has the capacity to fit
-                * these excess tasks, i.e. nr_running < group_capacity. The
+                * these excess tasks, i.e. nr_running < group_capacity_factor. The
                 * extra check prevents the case where you always pull from the
                 * heaviest group when it is already under-utilized (possible
                 * with a large weight task outweighs the tasks on the system).
                 */
                if (prefer_sibling && sds->local &&
-                   sds->local_stat.group_has_capacity)
-                       sgs->group_capacity = min(sgs->group_capacity, 1U);
+                   sds->local_stat.group_has_free_capacity)
+                       sgs->group_capacity_factor = min(sgs->group_capacity_factor, 1U);
 
                if (update_sd_pick_busiest(env, sds, sg, sgs)) {
                        sds->busiest = sg;
@@ -6038,7 +6042,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
 next_group:
                /* Now, start updating sd_lb_stats */
                sds->total_load += sgs->group_load;
-               sds->total_pwr += sgs->group_power;
+               sds->total_capacity += sgs->group_capacity;
 
                sg = sg->next;
        } while (sg != env->sd->groups);
@@ -6085,8 +6089,8 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
                return 0;
 
        env->imbalance = DIV_ROUND_CLOSEST(
-               sds->busiest_stat.avg_load * sds->busiest_stat.group_power,
-               SCHED_POWER_SCALE);
+               sds->busiest_stat.avg_load * sds->busiest_stat.group_capacity,
+               SCHED_CAPACITY_SCALE);
 
        return 1;
 }
@@ -6101,7 +6105,7 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
 static inline
 void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
 {
-       unsigned long tmp, pwr_now = 0, pwr_move = 0;
+       unsigned long tmp, capa_now = 0, capa_move = 0;
        unsigned int imbn = 2;
        unsigned long scaled_busy_load_per_task;
        struct sg_lb_stats *local, *busiest;
@@ -6115,8 +6119,8 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
                imbn = 1;
 
        scaled_busy_load_per_task =
-               (busiest->load_per_task * SCHED_POWER_SCALE) /
-               busiest->group_power;
+               (busiest->load_per_task * SCHED_CAPACITY_SCALE) /
+               busiest->group_capacity;
 
        if (busiest->avg_load + scaled_busy_load_per_task >=
            local->avg_load + (scaled_busy_load_per_task * imbn)) {
@@ -6126,38 +6130,38 @@ void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
 
        /*
         * OK, we don't have enough imbalance to justify moving tasks,
-        * however we may be able to increase total CPU power used by
+        * however we may be able to increase total CPU capacity used by
         * moving them.
         */
 
-       pwr_now += busiest->group_power *
+       capa_now += busiest->group_capacity *
                        min(busiest->load_per_task, busiest->avg_load);
-       pwr_now += local->group_power *
+       capa_now += local->group_capacity *
                        min(local->load_per_task, local->avg_load);
-       pwr_now /= SCHED_POWER_SCALE;
+       capa_now /= SCHED_CAPACITY_SCALE;
 
        /* Amount of load we'd subtract */
        if (busiest->avg_load > scaled_busy_load_per_task) {
-               pwr_move += busiest->group_power *
+               capa_move += busiest->group_capacity *
                            min(busiest->load_per_task,
                                busiest->avg_load - scaled_busy_load_per_task);
        }
 
        /* Amount of load we'd add */
-       if (busiest->avg_load * busiest->group_power <
-           busiest->load_per_task * SCHED_POWER_SCALE) {
-               tmp = (busiest->avg_load * busiest->group_power) /
-                     local->group_power;
+       if (busiest->avg_load * busiest->group_capacity <
+           busiest->load_per_task * SCHED_CAPACITY_SCALE) {
+               tmp = (busiest->avg_load * busiest->group_capacity) /
+                     local->group_capacity;
        } else {
-               tmp = (busiest->load_per_task * SCHED_POWER_SCALE) /
-                     local->group_power;
+               tmp = (busiest->load_per_task * SCHED_CAPACITY_SCALE) /
+                     local->group_capacity;
        }
-       pwr_move += local->group_power *
+       capa_move += local->group_capacity *
                    min(local->load_per_task, local->avg_load + tmp);
-       pwr_move /= SCHED_POWER_SCALE;
+       capa_move /= SCHED_CAPACITY_SCALE;
 
        /* Move if we gain throughput */
-       if (pwr_move > pwr_now)
+       if (capa_move > capa_now)
                env->imbalance = busiest->load_per_task;
 }
 
@@ -6187,7 +6191,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
        /*
         * In the presence of smp nice balancing, certain scenarios can have
         * max load less than avg load(as we skip the groups at or below
-        * its cpu_power, while calculating max_load..)
+        * its cpu_capacity, while calculating max_load..)
         */
        if (busiest->avg_load <= sds->avg_load ||
            local->avg_load >= sds->avg_load) {
@@ -6202,10 +6206,10 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
                 * have to drop below capacity to reach cpu-load equilibrium.
                 */
                load_above_capacity =
-                       (busiest->sum_nr_running - busiest->group_capacity);
+                       (busiest->sum_nr_running - busiest->group_capacity_factor);
 
-               load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE);
-               load_above_capacity /= busiest->group_power;
+               load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_CAPACITY_SCALE);
+               load_above_capacity /= busiest->group_capacity;
        }
 
        /*
@@ -6220,9 +6224,9 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
 
        /* How much load to actually move to equalise the imbalance */
        env->imbalance = min(
-               max_pull * busiest->group_power,
-               (sds->avg_load - local->avg_load) * local->group_power
-       ) / SCHED_POWER_SCALE;
+               max_pull * busiest->group_capacity,
+               (sds->avg_load - local->avg_load) * local->group_capacity
+       ) / SCHED_CAPACITY_SCALE;
 
        /*
         * if *imbalance is less than the average load per runnable task
@@ -6276,7 +6280,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
        if (!sds.busiest || busiest->sum_nr_running == 0)
                goto out_balanced;
 
-       sds.avg_load = (SCHED_POWER_SCALE * sds.total_load) / sds.total_pwr;
+       sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load)
+                                               / sds.total_capacity;
 
        /*
         * If the busiest group is imbalanced the below checks don't
@@ -6287,8 +6292,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
                goto force_balance;
 
        /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */
-       if (env->idle == CPU_NEWLY_IDLE && local->group_has_capacity &&
-           !busiest->group_has_capacity)
+       if (env->idle == CPU_NEWLY_IDLE && local->group_has_free_capacity &&
+           !busiest->group_has_free_capacity)
                goto force_balance;
 
        /*
@@ -6342,11 +6347,11 @@ static struct rq *find_busiest_queue(struct lb_env *env,
                                     struct sched_group *group)
 {
        struct rq *busiest = NULL, *rq;
-       unsigned long busiest_load = 0, busiest_power = 1;
+       unsigned long busiest_load = 0, busiest_capacity = 1;
        int i;
 
        for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
-               unsigned long power, capacity, wl;
+               unsigned long capacity, capacity_factor, wl;
                enum fbq_type rt;
 
                rq = cpu_rq(i);
@@ -6374,34 +6379,34 @@ static struct rq *find_busiest_queue(struct lb_env *env,
                if (rt > env->fbq_type)
                        continue;
 
-               power = power_of(i);
-               capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
-               if (!capacity)
-                       capacity = fix_small_capacity(env->sd, group);
+               capacity = capacity_of(i);
+               capacity_factor = DIV_ROUND_CLOSEST(capacity, SCHED_CAPACITY_SCALE);
+               if (!capacity_factor)
+                       capacity_factor = fix_small_capacity(env->sd, group);
 
                wl = weighted_cpuload(i);
 
                /*
                 * When comparing with imbalance, use weighted_cpuload()
-                * which is not scaled with the cpu power.
+                * which is not scaled with the cpu capacity.
                 */
-               if (capacity && rq->nr_running == 1 && wl > env->imbalance)
+               if (capacity_factor && rq->nr_running == 1 && wl > env->imbalance)
                        continue;
 
                /*
                 * For the load comparisons with the other cpu's, consider
-                * the weighted_cpuload() scaled with the cpu power, so that
-                * the load can be moved away from the cpu that is potentially
-                * running at a lower capacity.
+                * the weighted_cpuload() scaled with the cpu capacity, so
+                * that the load can be moved away from the cpu that is
+                * potentially running at a lower capacity.
                 *
-                * Thus we're looking for max(wl_i / power_i), crosswise
+                * Thus we're looking for max(wl_i / capacity_i), crosswise
                 * multiplication to rid ourselves of the division works out
-                * to: wl_i * power_j > wl_j * power_i;  where j is our
-                * previous maximum.
+                * to: wl_i * capacity_j > wl_j * capacity_i;  where j is
+                * our previous maximum.
                 */
-               if (wl * busiest_power > busiest_load * power) {
+               if (wl * busiest_capacity > busiest_load * capacity) {
                        busiest_load = wl;
-                       busiest_power = power;
+                       busiest_capacity = capacity;
                        busiest = rq;
                }
        }
@@ -6609,7 +6614,7 @@ more_balance:
                 * We failed to reach balance because of affinity.
                 */
                if (sd_parent) {
-                       int *group_imbalance = &sd_parent->groups->sgp->imbalance;
+                       int *group_imbalance = &sd_parent->groups->sgc->imbalance;
 
                        if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0) {
                                *group_imbalance = 1;
@@ -6996,7 +7001,7 @@ static inline void set_cpu_sd_state_busy(void)
                goto unlock;
        sd->nohz_idle = 0;
 
-       atomic_inc(&sd->groups->sgp->nr_busy_cpus);
+       atomic_inc(&sd->groups->sgc->nr_busy_cpus);
 unlock:
        rcu_read_unlock();
 }
@@ -7013,7 +7018,7 @@ void set_cpu_sd_state_idle(void)
                goto unlock;
        sd->nohz_idle = 1;
 
-       atomic_dec(&sd->groups->sgp->nr_busy_cpus);
+       atomic_dec(&sd->groups->sgc->nr_busy_cpus);
 unlock:
        rcu_read_unlock();
 }
@@ -7192,12 +7197,17 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 
                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(rq, CPU_IDLE);
+               /*
+                * If time for next balance is due,
+                * do the balance.
+                */
+               if (time_after_eq(jiffies, rq->next_balance)) {
+                       raw_spin_lock_irq(&rq->lock);
+                       update_rq_clock(rq);
+                       update_idle_cpu_load(rq);
+                       raw_spin_unlock_irq(&rq->lock);
+                       rebalance_domains(rq, CPU_IDLE);
+               }
 
                if (time_after(this_rq->next_balance, rq->next_balance))
                        this_rq->next_balance = rq->next_balance;
@@ -7212,7 +7222,7 @@ end:
  * of an idle cpu is the system.
  *   - This rq has more than one task.
  *   - At any scheduler domain level, this cpu's scheduler group has multiple
- *     busy cpu's exceeding the group's power.
+ *     busy cpu's exceeding the group's capacity.
  *   - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
  *     domain span are idle.
  */
@@ -7220,7 +7230,7 @@ static inline int nohz_kick_needed(struct rq *rq)
 {
        unsigned long now = jiffies;
        struct sched_domain *sd;
-       struct sched_group_power *sgp;
+       struct sched_group_capacity *sgc;
        int nr_busy, cpu = rq->cpu;
 
        if (unlikely(rq->idle_balance))
@@ -7250,8 +7260,8 @@ static inline int nohz_kick_needed(struct rq *rq)
        sd = rcu_dereference(per_cpu(sd_busy, cpu));
 
        if (sd) {
-               sgp = sd->groups->sgp;
-               nr_busy = atomic_read(&sgp->nr_busy_cpus);
+               sgc = sd->groups->sgc;
+               nr_busy = atomic_read(&sgc->nr_busy_cpus);
 
                if (nr_busy > 1)
                        goto need_kick_unlock;
index 5716929a2e3a4ad2d492ad2de0c3431291ea81a1..90284d117fe65ffc7ee1de7127995a750c84df92 100644 (file)
@@ -37,18 +37,18 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true)
 SCHED_FEAT(WAKEUP_PREEMPTION, true)
 
 /*
- * Use arch dependent cpu power functions
+ * Use arch dependent cpu capacity functions
  */
-SCHED_FEAT(ARCH_POWER, true)
+SCHED_FEAT(ARCH_CAPACITY, true)
 
 SCHED_FEAT(HRTICK, false)
 SCHED_FEAT(DOUBLE_TICK, false)
 SCHED_FEAT(LB_BIAS, true)
 
 /*
- * Decrement CPU power based on time not spent running tasks
+ * Decrement CPU capacity based on time not spent running tasks
  */
-SCHED_FEAT(NONTASK_POWER, true)
+SCHED_FEAT(NONTASK_CAPACITY, true)
 
 /*
  * Queue remote wakeups on the target CPU and process them
index 25b9423abce9fa54052abb49946ad6561f1dfed7..cf009fb0bc25b1427683d614a3a40ad98ad0c958 100644 (file)
@@ -12,6 +12,8 @@
 
 #include <trace/events/power.h>
 
+#include "sched.h"
+
 static int __read_mostly cpu_idle_force_poll;
 
 void cpu_idle_poll_ctrl(bool enable)
@@ -67,6 +69,10 @@ void __weak arch_cpu_idle(void)
  * cpuidle_idle_call - the main idle function
  *
  * NOTE: no locks or semaphores should be used here
+ *
+ * On archs that support TIF_POLLING_NRFLAG, is called with polling
+ * set, and it returns with polling set.  If it ever stops polling, it
+ * must clear the polling bit.
  */
 static void cpuidle_idle_call(void)
 {
@@ -175,10 +181,22 @@ exit_idle:
 
 /*
  * Generic idle loop implementation
+ *
+ * Called with polling cleared.
  */
 static void cpu_idle_loop(void)
 {
        while (1) {
+               /*
+                * If the arch has a polling bit, we maintain an invariant:
+                *
+                * Our polling bit is clear if we're not scheduled (i.e. if
+                * rq->curr != rq->idle).  This means that, if rq->idle has
+                * the polling bit set, then setting need_resched is
+                * guaranteed to cause the cpu to reschedule.
+                */
+
+               __current_set_polling();
                tick_nohz_idle_enter();
 
                while (!need_resched()) {
@@ -218,6 +236,17 @@ static void cpu_idle_loop(void)
                 */
                preempt_set_need_resched();
                tick_nohz_idle_exit();
+               __current_clr_polling();
+
+               /*
+                * We promise to call sched_ttwu_pending and reschedule
+                * if need_resched is set while polling is set.  That
+                * means that clearing polling needs to be visible
+                * before doing these things.
+                */
+               smp_mb__after_atomic();
+
+               sched_ttwu_pending();
                schedule_preempt_disabled();
        }
 }
@@ -239,7 +268,6 @@ void cpu_startup_entry(enum cpuhp_state state)
         */
        boot_init_stack_canary();
 #endif
-       __current_set_polling();
        arch_cpu_idle_prepare();
        cpu_idle_loop();
 }
index b3512f1afce9361588a8ccb50f7ad75540122426..a49083192c64c306952c752ec6b3a05a0df7205d 100644 (file)
@@ -918,7 +918,6 @@ static void update_curr_rt(struct rq *rq)
 {
        struct task_struct *curr = rq->curr;
        struct sched_rt_entity *rt_se = &curr->rt;
-       struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
        u64 delta_exec;
 
        if (curr->sched_class != &rt_sched_class)
@@ -943,7 +942,7 @@ static void update_curr_rt(struct rq *rq)
                return;
 
        for_each_sched_rt_entity(rt_se) {
-               rt_rq = rt_rq_of_se(rt_se);
+               struct rt_rq *rt_rq = rt_rq_of_se(rt_se);
 
                if (sched_rt_runtime(rt_rq) != RUNTIME_INF) {
                        raw_spin_lock(&rt_rq->rt_runtime_lock);
index e47679b04d167b8cdc2abf91326f7d52243b3996..31cc02ebc54ed82f5bf3f62fae879a1c0343a97d 100644 (file)
@@ -567,7 +567,7 @@ struct rq {
        struct root_domain *rd;
        struct sched_domain *sd;
 
-       unsigned long cpu_power;
+       unsigned long cpu_capacity;
 
        unsigned char idle_balance;
        /* For active balancing */
@@ -670,6 +670,8 @@ extern int migrate_swap(struct task_struct *, struct task_struct *);
 
 #ifdef CONFIG_SMP
 
+extern void sched_ttwu_pending(void);
+
 #define rcu_dereference_check_sched_domain(p) \
        rcu_dereference_check((p), \
                              lockdep_is_held(&sched_domains_mutex))
@@ -728,15 +730,15 @@ DECLARE_PER_CPU(struct sched_domain *, sd_numa);
 DECLARE_PER_CPU(struct sched_domain *, sd_busy);
 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
 
-struct sched_group_power {
+struct sched_group_capacity {
        atomic_t ref;
        /*
-        * CPU power of this group, SCHED_LOAD_SCALE being max power for a
-        * single CPU.
+        * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
+        * for a single CPU.
         */
-       unsigned int power, power_orig;
+       unsigned int capacity, capacity_orig;
        unsigned long next_update;
-       int imbalance; /* XXX unrelated to power but shared group state */
+       int imbalance; /* XXX unrelated to capacity but shared group state */
        /*
         * Number of busy cpus in this group.
         */
@@ -750,7 +752,7 @@ struct sched_group {
        atomic_t ref;
 
        unsigned int group_weight;
-       struct sched_group_power *sgp;
+       struct sched_group_capacity *sgc;
 
        /*
         * The CPUs this group covers.
@@ -773,7 +775,7 @@ static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
  */
 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
 {
-       return to_cpumask(sg->sgp->cpumask);
+       return to_cpumask(sg->sgc->cpumask);
 }
 
 /**
@@ -787,6 +789,10 @@ static inline unsigned int group_first_cpu(struct sched_group *group)
 
 extern int group_balance_cpu(struct sched_group *sg);
 
+#else
+
+static inline void sched_ttwu_pending(void) { }
+
 #endif /* CONFIG_SMP */
 
 #include "stats.h"
@@ -1167,7 +1173,7 @@ extern const struct sched_class idle_sched_class;
 
 #ifdef CONFIG_SMP
 
-extern void update_group_power(struct sched_domain *sd, int cpu);
+extern void update_group_capacity(struct sched_domain *sd, int cpu);
 
 extern void trigger_load_balance(struct rq *rq);
 
index c86be0f983db706c81cfe60aedfb77f4a315e20f..4b6c01b477f9cf86df4a69504de6940c5f6bebbf 100644 (file)
@@ -1714,11 +1714,11 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
 EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
 #endif /* !CONFIG_S390 */
 
-bool kvm_vcpu_yield_to(struct kvm_vcpu *target)
+int kvm_vcpu_yield_to(struct kvm_vcpu *target)
 {
        struct pid *pid;
        struct task_struct *task = NULL;
-       bool ret = false;
+       int ret = 0;
 
        rcu_read_lock();
        pid = rcu_dereference(target->pid);