Commit 15a3d11b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'sched-core-for-linus' of...

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()
parents 1f3a8e09 c8b28116
......@@ -786,17 +786,39 @@ enum cpu_idle_type {
};
/*
* sched-domains (multiprocessor balancing) declarations:
* Increase resolution of nice-level calculations for 64-bit architectures.
* The extra resolution improves shares distribution and load balancing of
* low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
* hierarchies, especially on larger systems. This is not a user-visible change
* and does not change the user-interface for setting shares/weights.
*
* We increase resolution only if we have enough bits to allow this increased
* resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
* when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
* increased costs.
*/
#if BITS_PER_LONG > 32
# define SCHED_LOAD_RESOLUTION 10
# define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
# define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
#else
# define SCHED_LOAD_RESOLUTION 0
# define scale_load(w) (w)
# define scale_load_down(w) (w)
#endif
/*
* Increase resolution of nice-level calculations:
*/
#define SCHED_LOAD_SHIFT 10
#define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
#define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
#define SCHED_LOAD_SCALE_FUZZ SCHED_LOAD_SCALE
/*
* Increase resolution of cpu_power calculations
*/
#define SCHED_POWER_SHIFT 10
#define SCHED_POWER_SCALE (1L << SCHED_POWER_SHIFT)
/*
* sched-domains (multiprocessor balancing) declarations:
*/
#ifdef CONFIG_SMP
#define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */
#define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
......
......@@ -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 */
......
......@@ -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;
......
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