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Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c324
1 files changed, 175 insertions, 149 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 2bbd948f016..53608a59d6e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1232,7 +1232,7 @@ nextgroup:
}
/*
- * find_idlest_queue - find the idlest runqueue among the cpus in group.
+ * find_idlest_cpu - find the idlest cpu among the cpus in group.
*/
static int
find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
@@ -1286,21 +1286,29 @@ static int sched_balance_self(int cpu, int flag)
while (sd) {
cpumask_t span;
struct sched_group *group;
- int new_cpu;
- int weight;
+ int new_cpu, weight;
+
+ if (!(sd->flags & flag)) {
+ sd = sd->child;
+ continue;
+ }
span = sd->span;
group = find_idlest_group(sd, t, cpu);
- if (!group)
- goto nextlevel;
+ if (!group) {
+ sd = sd->child;
+ continue;
+ }
new_cpu = find_idlest_cpu(group, t, cpu);
- if (new_cpu == -1 || new_cpu == cpu)
- goto nextlevel;
+ if (new_cpu == -1 || new_cpu == cpu) {
+ /* Now try balancing at a lower domain level of cpu */
+ sd = sd->child;
+ continue;
+ }
- /* Now try balancing at a lower domain level */
+ /* Now try balancing at a lower domain level of new_cpu */
cpu = new_cpu;
-nextlevel:
sd = NULL;
weight = cpus_weight(span);
for_each_domain(cpu, tmp) {
@@ -2533,8 +2541,14 @@ static int load_balance(int this_cpu, struct rq *this_rq,
struct rq *busiest;
cpumask_t cpus = CPU_MASK_ALL;
+ /*
+ * When power savings policy is enabled for the parent domain, idle
+ * sibling can pick up load irrespective of busy siblings. In this case,
+ * let the state of idle sibling percolate up as IDLE, instead of
+ * portraying it as NOT_IDLE.
+ */
if (idle != NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER &&
- !sched_smt_power_savings)
+ !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
sd_idle = 1;
schedstat_inc(sd, lb_cnt[idle]);
@@ -2630,7 +2644,7 @@ redo:
}
if (!nr_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
- !sched_smt_power_savings)
+ !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
return -1;
return nr_moved;
@@ -2646,7 +2660,7 @@ out_one_pinned:
sd->balance_interval *= 2;
if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
- !sched_smt_power_savings)
+ !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
return -1;
return 0;
}
@@ -2668,7 +2682,14 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
int sd_idle = 0;
cpumask_t cpus = CPU_MASK_ALL;
- if (sd->flags & SD_SHARE_CPUPOWER && !sched_smt_power_savings)
+ /*
+ * When power savings policy is enabled for the parent domain, idle
+ * sibling can pick up load irrespective of busy siblings. In this case,
+ * let the state of idle sibling percolate up as IDLE, instead of
+ * portraying it as NOT_IDLE.
+ */
+ if (sd->flags & SD_SHARE_CPUPOWER &&
+ !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
sd_idle = 1;
schedstat_inc(sd, lb_cnt[NEWLY_IDLE]);
@@ -2709,7 +2730,8 @@ redo:
if (!nr_moved) {
schedstat_inc(sd, lb_failed[NEWLY_IDLE]);
- if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER)
+ if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
+ !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
return -1;
} else
sd->nr_balance_failed = 0;
@@ -2719,7 +2741,7 @@ redo:
out_balanced:
schedstat_inc(sd, lb_balanced[NEWLY_IDLE]);
if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
- !sched_smt_power_savings)
+ !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
return -1;
sd->nr_balance_failed = 0;
@@ -4384,7 +4406,10 @@ EXPORT_SYMBOL(cpu_present_map);
#ifndef CONFIG_SMP
cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
+EXPORT_SYMBOL(cpu_online_map);
+
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
+EXPORT_SYMBOL(cpu_possible_map);
#endif
long sched_getaffinity(pid_t pid, cpumask_t *mask)
@@ -4814,7 +4839,7 @@ void show_state(void)
* NOTE: this function does not set the idle thread's NEED_RESCHED
* flag, to make booting more robust.
*/
-void __devinit init_idle(struct task_struct *idle, int cpu)
+void __cpuinit init_idle(struct task_struct *idle, int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
@@ -5389,7 +5414,9 @@ static int sd_degenerate(struct sched_domain *sd)
if (sd->flags & (SD_LOAD_BALANCE |
SD_BALANCE_NEWIDLE |
SD_BALANCE_FORK |
- SD_BALANCE_EXEC)) {
+ SD_BALANCE_EXEC |
+ SD_SHARE_CPUPOWER |
+ SD_SHARE_PKG_RESOURCES)) {
if (sd->groups != sd->groups->next)
return 0;
}
@@ -5423,7 +5450,9 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
pflags &= ~(SD_LOAD_BALANCE |
SD_BALANCE_NEWIDLE |
SD_BALANCE_FORK |
- SD_BALANCE_EXEC);
+ SD_BALANCE_EXEC |
+ SD_SHARE_CPUPOWER |
+ SD_SHARE_PKG_RESOURCES);
}
if (~cflags & pflags)
return 0;
@@ -5445,12 +5474,18 @@ static void cpu_attach_domain(struct sched_domain *sd, int cpu)
struct sched_domain *parent = tmp->parent;
if (!parent)
break;
- if (sd_parent_degenerate(tmp, parent))
+ if (sd_parent_degenerate(tmp, parent)) {
tmp->parent = parent->parent;
+ if (parent->parent)
+ parent->parent->child = tmp;
+ }
}
- if (sd && sd_degenerate(sd))
+ if (sd && sd_degenerate(sd)) {
sd = sd->parent;
+ if (sd)
+ sd->child = NULL;
+ }
sched_domain_debug(sd, cpu);
@@ -5458,7 +5493,7 @@ static void cpu_attach_domain(struct sched_domain *sd, int cpu)
}
/* cpus with isolated domains */
-static cpumask_t __devinitdata cpu_isolated_map = CPU_MASK_NONE;
+static cpumask_t __cpuinitdata cpu_isolated_map = CPU_MASK_NONE;
/* Setup the mask of cpus configured for isolated domains */
static int __init isolated_cpu_setup(char *str)
@@ -5486,15 +5521,17 @@ __setup ("isolcpus=", isolated_cpu_setup);
* covered by the given span, and will set each group's ->cpumask correctly,
* and ->cpu_power to 0.
*/
-static void init_sched_build_groups(struct sched_group groups[], cpumask_t span,
- int (*group_fn)(int cpu))
+static void
+init_sched_build_groups(struct sched_group groups[], cpumask_t span,
+ const cpumask_t *cpu_map,
+ int (*group_fn)(int cpu, const cpumask_t *cpu_map))
{
struct sched_group *first = NULL, *last = NULL;
cpumask_t covered = CPU_MASK_NONE;
int i;
for_each_cpu_mask(i, span) {
- int group = group_fn(i);
+ int group = group_fn(i, cpu_map);
struct sched_group *sg = &groups[group];
int j;
@@ -5505,7 +5542,7 @@ static void init_sched_build_groups(struct sched_group groups[], cpumask_t span,
sg->cpu_power = 0;
for_each_cpu_mask(j, span) {
- if (group_fn(j) != group)
+ if (group_fn(j, cpu_map) != group)
continue;
cpu_set(j, covered);
@@ -5972,13 +6009,15 @@ static void calibrate_migration_costs(const cpumask_t *cpu_map)
#endif
);
if (system_state == SYSTEM_BOOTING) {
- printk("migration_cost=");
- for (distance = 0; distance <= max_distance; distance++) {
- if (distance)
- printk(",");
- printk("%ld", (long)migration_cost[distance] / 1000);
+ if (num_online_cpus() > 1) {
+ printk("migration_cost=");
+ for (distance = 0; distance <= max_distance; distance++) {
+ if (distance)
+ printk(",");
+ printk("%ld", (long)migration_cost[distance] / 1000);
+ }
+ printk("\n");
}
- printk("\n");
}
j1 = jiffies;
if (migration_debug)
@@ -6081,7 +6120,7 @@ int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
static DEFINE_PER_CPU(struct sched_domain, cpu_domains);
static struct sched_group sched_group_cpus[NR_CPUS];
-static int cpu_to_cpu_group(int cpu)
+static int cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map)
{
return cpu;
}
@@ -6092,31 +6131,36 @@ static int cpu_to_cpu_group(int cpu)
*/
#ifdef CONFIG_SCHED_MC
static DEFINE_PER_CPU(struct sched_domain, core_domains);
-static struct sched_group *sched_group_core_bycpu[NR_CPUS];
+static struct sched_group sched_group_core[NR_CPUS];
#endif
#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
-static int cpu_to_core_group(int cpu)
+static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map)
{
- return first_cpu(cpu_sibling_map[cpu]);
+ cpumask_t mask = cpu_sibling_map[cpu];
+ cpus_and(mask, mask, *cpu_map);
+ return first_cpu(mask);
}
#elif defined(CONFIG_SCHED_MC)
-static int cpu_to_core_group(int cpu)
+static int cpu_to_core_group(int cpu, const cpumask_t *cpu_map)
{
return cpu;
}
#endif
static DEFINE_PER_CPU(struct sched_domain, phys_domains);
-static struct sched_group *sched_group_phys_bycpu[NR_CPUS];
+static struct sched_group sched_group_phys[NR_CPUS];
-static int cpu_to_phys_group(int cpu)
+static int cpu_to_phys_group(int cpu, const cpumask_t *cpu_map)
{
#ifdef CONFIG_SCHED_MC
cpumask_t mask = cpu_coregroup_map(cpu);
+ cpus_and(mask, mask, *cpu_map);
return first_cpu(mask);
#elif defined(CONFIG_SCHED_SMT)
- return first_cpu(cpu_sibling_map[cpu]);
+ cpumask_t mask = cpu_sibling_map[cpu];
+ cpus_and(mask, mask, *cpu_map);
+ return first_cpu(mask);
#else
return cpu;
#endif
@@ -6134,7 +6178,7 @@ static struct sched_group **sched_group_nodes_bycpu[NR_CPUS];
static DEFINE_PER_CPU(struct sched_domain, allnodes_domains);
static struct sched_group *sched_group_allnodes_bycpu[NR_CPUS];
-static int cpu_to_allnodes_group(int cpu)
+static int cpu_to_allnodes_group(int cpu, const cpumask_t *cpu_map)
{
return cpu_to_node(cpu);
}
@@ -6166,12 +6210,11 @@ next_sg:
}
#endif
+#ifdef CONFIG_NUMA
/* Free memory allocated for various sched_group structures */
static void free_sched_groups(const cpumask_t *cpu_map)
{
- int cpu;
-#ifdef CONFIG_NUMA
- int i;
+ int cpu, i;
for_each_cpu_mask(cpu, *cpu_map) {
struct sched_group *sched_group_allnodes
@@ -6208,19 +6251,63 @@ next_sg:
kfree(sched_group_nodes);
sched_group_nodes_bycpu[cpu] = NULL;
}
+}
+#else
+static void free_sched_groups(const cpumask_t *cpu_map)
+{
+}
#endif
- for_each_cpu_mask(cpu, *cpu_map) {
- if (sched_group_phys_bycpu[cpu]) {
- kfree(sched_group_phys_bycpu[cpu]);
- sched_group_phys_bycpu[cpu] = NULL;
- }
-#ifdef CONFIG_SCHED_MC
- if (sched_group_core_bycpu[cpu]) {
- kfree(sched_group_core_bycpu[cpu]);
- sched_group_core_bycpu[cpu] = NULL;
- }
-#endif
+
+/*
+ * Initialize sched groups cpu_power.
+ *
+ * cpu_power 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.
+ *
+ * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
+ * the maximum number of tasks a group can handle in the presence of other idle
+ * or lightly loaded groups in the same sched domain.
+ */
+static void init_sched_groups_power(int cpu, struct sched_domain *sd)
+{
+ struct sched_domain *child;
+ struct sched_group *group;
+
+ WARN_ON(!sd || !sd->groups);
+
+ if (cpu != first_cpu(sd->groups->cpumask))
+ return;
+
+ child = sd->child;
+
+ /*
+ * For perf policy, if the groups in child domain share resources
+ * (for example cores sharing some portions of the cache hierarchy
+ * or SMT), then set this domain groups cpu_power such that each group
+ * can handle only one task, when there are other idle groups in the
+ * same sched domain.
+ */
+ if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
+ (child->flags &
+ (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
+ sd->groups->cpu_power = SCHED_LOAD_SCALE;
+ return;
}
+
+ sd->groups->cpu_power = 0;
+
+ /*
+ * add cpu_power of each child group to this groups cpu_power
+ */
+ group = child->groups;
+ do {
+ sd->groups->cpu_power += group->cpu_power;
+ group = group->next;
+ } while (group != child->groups);
}
/*
@@ -6230,10 +6317,7 @@ next_sg:
static int build_sched_domains(const cpumask_t *cpu_map)
{
int i;
- struct sched_group *sched_group_phys = NULL;
-#ifdef CONFIG_SCHED_MC
- struct sched_group *sched_group_core = NULL;
-#endif
+ struct sched_domain *sd;
#ifdef CONFIG_NUMA
struct sched_group **sched_group_nodes = NULL;
struct sched_group *sched_group_allnodes = NULL;
@@ -6265,9 +6349,10 @@ static int build_sched_domains(const cpumask_t *cpu_map)
> SD_NODES_PER_DOMAIN*cpus_weight(nodemask)) {
if (!sched_group_allnodes) {
sched_group_allnodes
- = kmalloc(sizeof(struct sched_group)
- * MAX_NUMNODES,
- GFP_KERNEL);
+ = kmalloc_node(sizeof(struct sched_group)
+ * MAX_NUMNODES,
+ GFP_KERNEL,
+ cpu_to_node(i));
if (!sched_group_allnodes) {
printk(KERN_WARNING
"Can not alloc allnodes sched group\n");
@@ -6279,7 +6364,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
sd = &per_cpu(allnodes_domains, i);
*sd = SD_ALLNODES_INIT;
sd->span = *cpu_map;
- group = cpu_to_allnodes_group(i);
+ group = cpu_to_allnodes_group(i, cpu_map);
sd->groups = &sched_group_allnodes[group];
p = sd;
} else
@@ -6289,60 +6374,42 @@ static int build_sched_domains(const cpumask_t *cpu_map)
*sd = SD_NODE_INIT;
sd->span = sched_domain_node_span(cpu_to_node(i));
sd->parent = p;
+ if (p)
+ p->child = sd;
cpus_and(sd->span, sd->span, *cpu_map);
#endif
- if (!sched_group_phys) {
- sched_group_phys
- = kmalloc(sizeof(struct sched_group) * NR_CPUS,
- GFP_KERNEL);
- if (!sched_group_phys) {
- printk (KERN_WARNING "Can not alloc phys sched"
- "group\n");
- goto error;
- }
- sched_group_phys_bycpu[i] = sched_group_phys;
- }
-
p = sd;
sd = &per_cpu(phys_domains, i);
- group = cpu_to_phys_group(i);
+ group = cpu_to_phys_group(i, cpu_map);
*sd = SD_CPU_INIT;
sd->span = nodemask;
sd->parent = p;
+ if (p)
+ p->child = sd;
sd->groups = &sched_group_phys[group];
#ifdef CONFIG_SCHED_MC
- if (!sched_group_core) {
- sched_group_core
- = kmalloc(sizeof(struct sched_group) * NR_CPUS,
- GFP_KERNEL);
- if (!sched_group_core) {
- printk (KERN_WARNING "Can not alloc core sched"
- "group\n");
- goto error;
- }
- sched_group_core_bycpu[i] = sched_group_core;
- }
-
p = sd;
sd = &per_cpu(core_domains, i);
- group = cpu_to_core_group(i);
+ group = cpu_to_core_group(i, cpu_map);
*sd = SD_MC_INIT;
sd->span = cpu_coregroup_map(i);
cpus_and(sd->span, sd->span, *cpu_map);
sd->parent = p;
+ p->child = sd;
sd->groups = &sched_group_core[group];
#endif
#ifdef CONFIG_SCHED_SMT
p = sd;
sd = &per_cpu(cpu_domains, i);
- group = cpu_to_cpu_group(i);
+ group = cpu_to_cpu_group(i, cpu_map);
*sd = SD_SIBLING_INIT;
sd->span = cpu_sibling_map[i];
cpus_and(sd->span, sd->span, *cpu_map);
sd->parent = p;
+ p->child = sd;
sd->groups = &sched_group_cpus[group];
#endif
}
@@ -6356,7 +6423,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
continue;
init_sched_build_groups(sched_group_cpus, this_sibling_map,
- &cpu_to_cpu_group);
+ cpu_map, &cpu_to_cpu_group);
}
#endif
@@ -6368,7 +6435,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
if (i != first_cpu(this_core_map))
continue;
init_sched_build_groups(sched_group_core, this_core_map,
- &cpu_to_core_group);
+ cpu_map, &cpu_to_core_group);
}
#endif
@@ -6382,14 +6449,14 @@ static int build_sched_domains(const cpumask_t *cpu_map)
continue;
init_sched_build_groups(sched_group_phys, nodemask,
- &cpu_to_phys_group);
+ cpu_map, &cpu_to_phys_group);
}
#ifdef CONFIG_NUMA
/* Set up node groups */
if (sched_group_allnodes)
init_sched_build_groups(sched_group_allnodes, *cpu_map,
- &cpu_to_allnodes_group);
+ cpu_map, &cpu_to_allnodes_group);
for (i = 0; i < MAX_NUMNODES; i++) {
/* Set up node groups */
@@ -6461,72 +6528,20 @@ static int build_sched_domains(const cpumask_t *cpu_map)
/* Calculate CPU power for physical packages and nodes */
#ifdef CONFIG_SCHED_SMT
for_each_cpu_mask(i, *cpu_map) {
- struct sched_domain *sd;
sd = &per_cpu(cpu_domains, i);
- sd->groups->cpu_power = SCHED_LOAD_SCALE;
+ init_sched_groups_power(i, sd);
}
#endif
#ifdef CONFIG_SCHED_MC
for_each_cpu_mask(i, *cpu_map) {
- int power;
- struct sched_domain *sd;
sd = &per_cpu(core_domains, i);
- if (sched_smt_power_savings)
- power = SCHED_LOAD_SCALE * cpus_weight(sd->groups->cpumask);
- else
- power = SCHED_LOAD_SCALE + (cpus_weight(sd->groups->cpumask)-1)
- * SCHED_LOAD_SCALE / 10;
- sd->groups->cpu_power = power;
+ init_sched_groups_power(i, sd);
}
#endif
for_each_cpu_mask(i, *cpu_map) {
- struct sched_domain *sd;
-#ifdef CONFIG_SCHED_MC
sd = &per_cpu(phys_domains, i);
- if (i != first_cpu(sd->groups->cpumask))
- continue;
-
- sd->groups->cpu_power = 0;
- if (sched_mc_power_savings || sched_smt_power_savings) {
- int j;
-
- for_each_cpu_mask(j, sd->groups->cpumask) {
- struct sched_domain *sd1;
- sd1 = &per_cpu(core_domains, j);
- /*
- * for each core we will add once
- * to the group in physical domain
- */
- if (j != first_cpu(sd1->groups->cpumask))
- continue;
-
- if (sched_smt_power_savings)
- sd->groups->cpu_power += sd1->groups->cpu_power;
- else
- sd->groups->cpu_power += SCHED_LOAD_SCALE;
- }
- } else
- /*
- * This has to be < 2 * SCHED_LOAD_SCALE
- * Lets keep it SCHED_LOAD_SCALE, so that
- * while calculating NUMA group's cpu_power
- * we can simply do
- * numa_group->cpu_power += phys_group->cpu_power;
- *
- * See "only add power once for each physical pkg"
- * comment below
- */
- sd->groups->cpu_power = SCHED_LOAD_SCALE;
-#else
- int power;
- sd = &per_cpu(phys_domains, i);
- if (sched_smt_power_savings)
- power = SCHED_LOAD_SCALE * cpus_weight(sd->groups->cpumask);
- else
- power = SCHED_LOAD_SCALE;
- sd->groups->cpu_power = power;
-#endif
+ init_sched_groups_power(i, sd);
}
#ifdef CONFIG_NUMA
@@ -6534,7 +6549,7 @@ static int build_sched_domains(const cpumask_t *cpu_map)
init_numa_sched_groups_power(sched_group_nodes[i]);
if (sched_group_allnodes) {
- int group = cpu_to_allnodes_group(first_cpu(*cpu_map));
+ int group = cpu_to_allnodes_group(first_cpu(*cpu_map), cpu_map);
struct sched_group *sg = &sched_group_allnodes[group];
init_numa_sched_groups_power(sg);
@@ -6560,9 +6575,11 @@ static int build_sched_domains(const cpumask_t *cpu_map)
return 0;
+#ifdef CONFIG_NUMA
error:
free_sched_groups(cpu_map);
return -ENOMEM;
+#endif
}
/*
* Set up scheduler domains and groups. Callers must hold the hotplug lock.
@@ -6744,11 +6761,20 @@ static int update_sched_domains(struct notifier_block *nfb,
void __init sched_init_smp(void)
{
+ cpumask_t non_isolated_cpus;
+
lock_cpu_hotplug();
arch_init_sched_domains(&cpu_online_map);
+ cpus_andnot(non_isolated_cpus, cpu_online_map, cpu_isolated_map);
+ if (cpus_empty(non_isolated_cpus))
+ cpu_set(smp_processor_id(), non_isolated_cpus);
unlock_cpu_hotplug();
/* XXX: Theoretical race here - CPU may be hotplugged now */
hotcpu_notifier(update_sched_domains, 0);
+
+ /* Move init over to a non-isolated CPU */
+ if (set_cpus_allowed(current, non_isolated_cpus) < 0)
+ BUG();
}
#else
void __init sched_init_smp(void)