Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Increase SCHED_LOAD_SCALE resolution
  sched: Introduce SCHED_POWER_SCALE to scale cpu_power calculations
  sched: Cleanup set_load_weight()

2 files changed, 54 insertions, 37 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 0516af415085..2d12893b8b0f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -293,7 +293,7 @@ static DEFINE_SPINLOCK(task_group_lock);
  *  limitation from this.)
  */
 #define MIN_SHARES      2
-#define MAX_SHARES      (1UL << 18)
+#define MAX_SHARES      (1UL << (18 + SCHED_LOAD_RESOLUTION))
 
 static int root_task_group_load = ROOT_TASK_GROUP_LOAD;
 #endif
@@ -1330,13 +1330,25 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
 {
         u64 tmp;
 
-        tmp = (u64)delta_exec * weight;
+        /*
+         * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched
+         * entities since MIN_SHARES = 2. Treat weight as 1 if less than
+         * 2^SCHED_LOAD_RESOLUTION.
+         */
+        if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION)))
+                tmp = (u64)delta_exec * scale_load_down(weight);
+        else
+                tmp = (u64)delta_exec;
 
         if (!lw->inv_weight) {
-                if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST))
+                unsigned long w = scale_load_down(lw->weight);
+
+                if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
                         lw->inv_weight = 1;
+                else if (unlikely(!w))
+                        lw->inv_weight = WMULT_CONST;
                 else
-                        lw->inv_weight = WMULT_CONST / lw->weight;
+                        lw->inv_weight = WMULT_CONST / w;
         }
 
         /*
@@ -1778,17 +1790,20 @@ static void dec_nr_running(struct rq *rq)
 
 static void set_load_weight(struct task_struct *p)
 {
+        int prio = p->static_prio - MAX_RT_PRIO;
+        struct load_weight *load = &p->se.load;
+
         /*
          * SCHED_IDLE tasks get minimal weight:
          */
         if (p->policy == SCHED_IDLE) {
-                p->se.load.weight = WEIGHT_IDLEPRIO;
-                p->se.load.inv_weight = WMULT_IDLEPRIO;
+                load->weight = scale_load(WEIGHT_IDLEPRIO);
+                load->inv_weight = WMULT_IDLEPRIO;
                 return;
         }
 
-        p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO];
-        p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO];
+        load->weight = scale_load(prio_to_weight[prio]);
+        load->inv_weight = prio_to_wmult[prio];
 }
 
 static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
@@ -6527,7 +6542,7 @@ 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->cpu_power != SCHED_LOAD_SCALE) {
+                if (group->cpu_power != SCHED_POWER_SCALE) {
                         printk(KERN_CONT " (cpu_power = %d)",
                                 group->cpu_power);
                 }
@@ -7902,7 +7917,7 @@ void __init sched_init(void)
 #ifdef CONFIG_SMP
                 rq->sd = NULL;
                 rq->rd = NULL;
-                rq->cpu_power = SCHED_LOAD_SCALE;
+                rq->cpu_power = SCHED_POWER_SCALE;
                 rq->post_schedule = 0;
                 rq->active_balance = 0;
                 rq->next_balance = jiffies;
@@ -8806,14 +8821,14 @@ cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
 static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype,
                                 u64 shareval)
 {
-        return sched_group_set_shares(cgroup_tg(cgrp), shareval);
+        return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval));
 }
 
 static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
 {
         struct task_group *tg = cgroup_tg(cgrp);
 
-        return (u64) tg->shares;
+        return (u64) scale_load_down(tg->shares);
 }
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 37f22626225e..e32a9b70ee9c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1584,7 +1584,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p,
                 }
 
                 /* Adjust by relative CPU power of the group */
-                avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power;
+                avg_load = (avg_load * SCHED_POWER_SCALE) / group->cpu_power;
 
                 if (local_group) {
                         this_load = avg_load;
@@ -1722,7 +1722,7 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
                                 nr_running += cpu_rq(i)->cfs.nr_running;
                         }
 
-                        capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE);
+                        capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
 
                         if (tmp->flags & SD_POWERSAVINGS_BALANCE)
                                 nr_running /= 2;
@@ -2570,7 +2570,7 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
 
 unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
 {
-        return SCHED_LOAD_SCALE;
+        return SCHED_POWER_SCALE;
 }
 
 unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu)
@@ -2607,10 +2607,10 @@ unsigned long scale_rt_power(int cpu)
                 available = total - rq->rt_avg;
         }
 
-        if (unlikely((s64)total < SCHED_LOAD_SCALE))
-                total = SCHED_LOAD_SCALE;
+        if (unlikely((s64)total < SCHED_POWER_SCALE))
+                total = SCHED_POWER_SCALE;
 
-        total >>= SCHED_LOAD_SHIFT;
+        total >>= SCHED_POWER_SHIFT;
 
         return div_u64(available, total);
 }
@@ -2618,7 +2618,7 @@ unsigned long scale_rt_power(int cpu)
 static void update_cpu_power(struct sched_domain *sd, int cpu)
 {
         unsigned long weight = sd->span_weight;
-        unsigned long power = SCHED_LOAD_SCALE;
+        unsigned long power = SCHED_POWER_SCALE;
         struct sched_group *sdg = sd->groups;
 
         if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
@@ -2627,7 +2627,7 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
                 else
                         power *= default_scale_smt_power(sd, cpu);
 
-                power >>= SCHED_LOAD_SHIFT;
+                power >>= SCHED_POWER_SHIFT;
         }
 
         sdg->cpu_power_orig = power;
@@ -2637,10 +2637,10 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
         else
                 power *= default_scale_freq_power(sd, cpu);
 
-        power >>= SCHED_LOAD_SHIFT;
+        power >>= SCHED_POWER_SHIFT;
 
         power *= scale_rt_power(cpu);
-        power >>= SCHED_LOAD_SHIFT;
+        power >>= SCHED_POWER_SHIFT;
 
         if (!power)
                 power = 1;
@@ -2682,7 +2682,7 @@ static inline int
 fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
 {
         /*
-         * Only siblings can have significantly less than SCHED_LOAD_SCALE
+         * Only siblings can have significantly less than SCHED_POWER_SCALE
          */
         if (!(sd->flags & SD_SHARE_CPUPOWER))
                 return 0;
@@ -2770,7 +2770,7 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
         }
 
         /* Adjust by relative CPU power of the group */
-        sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power;
+        sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / group->cpu_power;
 
         /*
          * Consider the group unbalanced when the imbalance is larger
@@ -2787,7 +2787,8 @@ static inline void update_sg_lb_stats(struct sched_domain *sd,
         if ((max_cpu_load - min_cpu_load) >= avg_load_per_task && max_nr_running > 1)
                 sgs->group_imb = 1;
 
-        sgs->group_capacity = DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE);
+        sgs->group_capacity = DIV_ROUND_CLOSEST(group->cpu_power,
+                                                SCHED_POWER_SCALE);
         if (!sgs->group_capacity)
                 sgs->group_capacity = fix_small_capacity(sd, group);
         sgs->group_weight = group->group_weight;
@@ -2961,7 +2962,7 @@ static int check_asym_packing(struct sched_domain *sd,
                 return 0;
 
         *imbalance = DIV_ROUND_CLOSEST(sds->max_load * sds->busiest->cpu_power,
-                                       SCHED_LOAD_SCALE);
+                                       SCHED_POWER_SCALE);
         return 1;
 }
 
@@ -2990,7 +2991,7 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
                         cpu_avg_load_per_task(this_cpu);
 
         scaled_busy_load_per_task = sds->busiest_load_per_task
-                                                 * SCHED_LOAD_SCALE;
+                                         * SCHED_POWER_SCALE;
         scaled_busy_load_per_task /= sds->busiest->cpu_power;
 
         if (sds->max_load - sds->this_load + scaled_busy_load_per_task >=
@@ -3009,10 +3010,10 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
                         min(sds->busiest_load_per_task, sds->max_load);
         pwr_now += sds->this->cpu_power *
                         min(sds->this_load_per_task, sds->this_load);
-        pwr_now /= SCHED_LOAD_SCALE;
+        pwr_now /= SCHED_POWER_SCALE;
 
         /* Amount of load we'd subtract */
-        tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) /
+        tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
                 sds->busiest->cpu_power;
         if (sds->max_load > tmp)
                 pwr_move += sds->busiest->cpu_power *
@@ -3020,15 +3021,15 @@ static inline void fix_small_imbalance(struct sd_lb_stats *sds,
 
         /* Amount of load we'd add */
         if (sds->max_load * sds->busiest->cpu_power <
-                sds->busiest_load_per_task * SCHED_LOAD_SCALE)
+                sds->busiest_load_per_task * SCHED_POWER_SCALE)
                 tmp = (sds->max_load * sds->busiest->cpu_power) /
                         sds->this->cpu_power;
         else
-                tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) /
+                tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
                         sds->this->cpu_power;
         pwr_move += sds->this->cpu_power *
                         min(sds->this_load_per_task, sds->this_load + tmp);
-        pwr_move /= SCHED_LOAD_SCALE;
+        pwr_move /= SCHED_POWER_SCALE;
 
         /* Move if we gain throughput */
         if (pwr_move > pwr_now)
@@ -3070,7 +3071,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
                 load_above_capacity = (sds->busiest_nr_running -
                                                 sds->busiest_group_capacity);
 
-                load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_LOAD_SCALE);
+                load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE);
 
                 load_above_capacity /= sds->busiest->cpu_power;
         }
@@ -3090,7 +3091,7 @@ static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
         /* How much load to actually move to equalise the imbalance */
         *imbalance = min(max_pull * sds->busiest->cpu_power,
                 (sds->avg_load - sds->this_load) * sds->this->cpu_power)
-                        / SCHED_LOAD_SCALE;
+                        / SCHED_POWER_SCALE;
 
         /*
          * if *imbalance is less than the average load per runnable task
@@ -3159,7 +3160,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
         if (!sds.busiest || sds.busiest_nr_running == 0)
                 goto out_balanced;
 
-        sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr;
+        sds.avg_load = (SCHED_POWER_SCALE * sds.total_load) / sds.total_pwr;
 
         /*
          * If the busiest group is imbalanced the below checks don't
@@ -3238,7 +3239,8 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
 
         for_each_cpu(i, sched_group_cpus(group)) {
                 unsigned long power = power_of(i);
-                unsigned long capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE);
+                unsigned long capacity = DIV_ROUND_CLOSEST(power,
+                                                           SCHED_POWER_SCALE);
                 unsigned long wl;
 
                 if (!capacity)
@@ -3263,7 +3265,7 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
                  * the load can be moved away from the cpu that is potentially
                  * running at a lower capacity.
                  */
-                wl = (wl * SCHED_LOAD_SCALE) / power;
+                wl = (wl * SCHED_POWER_SCALE) / power;
 
                 if (wl > max_load) {
                         max_load = wl;