return (unsigned long long)jiffies * (1000000000 / HZ);
}
-#ifdef CONFIG_SMP
-#define is_migration_thread(p, rq) ((p) == (rq)->migration_thread)
-#else
-#define is_migration_thread(p, rq) 0
-#endif
-
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
#ifdef CONFIG_SMP
+/*
+ * Is this task likely cache-hot:
+ */
+static inline int
+task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
+{
+ s64 delta;
+
+ if (p->sched_class != &fair_sched_class)
+ return 0;
+
+ if (sysctl_sched_migration_cost == -1)
+ return 1;
+ if (sysctl_sched_migration_cost == 0)
+ return 0;
+
+ delta = now - p->se.exec_start;
+
+ return delta < (s64)sysctl_sched_migration_cost;
+}
+
+
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
int old_cpu = task_cpu(p);
p->se.sleep_start -= clock_offset;
if (p->se.block_start)
p->se.block_start -= clock_offset;
+ if (old_cpu != new_cpu) {
+ schedstat_inc(p, se.nr_migrations);
+ if (task_hot(p, old_rq->clock, NULL))
+ schedstat_inc(p, se.nr_forced2_migrations);
+ }
#endif
p->se.vruntime -= old_cfsrq->min_vruntime -
new_cfsrq->min_vruntime;
if (sd->flags & SD_WAKE_IDLE) {
cpus_and(tmp, sd->span, p->cpus_allowed);
for_each_cpu_mask(i, tmp) {
- if (idle_cpu(i))
+ if (idle_cpu(i)) {
+ if (i != task_cpu(p)) {
+ schedstat_inc(p,
+ se.nr_wakeups_idle);
+ }
return i;
+ }
}
} else {
break;
*/
static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
{
- int cpu, this_cpu, success = 0;
+ int cpu, orig_cpu, this_cpu, success = 0;
unsigned long flags;
long old_state;
struct rq *rq;
goto out_running;
cpu = task_cpu(p);
+ orig_cpu = cpu;
this_cpu = smp_processor_id();
#ifdef CONFIG_SMP
unsigned long tl = this_load;
unsigned long tl_per_task;
+ /*
+ * Attract cache-cold tasks on sync wakeups:
+ */
+ if (sync && !task_hot(p, rq->clock, this_sd))
+ goto out_set_cpu;
+
+ schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
/*
* there is no bad imbalance.
*/
schedstat_inc(this_sd, ttwu_move_affine);
+ schedstat_inc(p, se.nr_wakeups_affine);
goto out_set_cpu;
}
}
if (this_sd->flags & SD_WAKE_BALANCE) {
if (imbalance*this_load <= 100*load) {
schedstat_inc(this_sd, ttwu_move_balance);
+ schedstat_inc(p, se.nr_wakeups_passive);
goto out_set_cpu;
}
}
out_activate:
#endif /* CONFIG_SMP */
+ schedstat_inc(p, se.nr_wakeups);
+ if (sync)
+ schedstat_inc(p, se.nr_wakeups_sync);
+ if (orig_cpu != cpu)
+ schedstat_inc(p, se.nr_wakeups_migrate);
+ if (cpu == this_cpu)
+ schedstat_inc(p, se.nr_wakeups_local);
+ else
+ schedstat_inc(p, se.nr_wakeups_remote);
update_rq_clock(rq);
activate_task(rq, p, 1);
- /*
- * Sync wakeups (i.e. those types of wakeups where the waker
- * has indicated that it will leave the CPU in short order)
- * don't trigger a preemption, if the woken up task will run on
- * this cpu. (in this case the 'I will reschedule' promise of
- * the waker guarantees that the freshly woken up task is going
- * to be considered on this CPU.)
- */
- if (!sync || cpu != this_cpu)
- check_preempt_curr(rq, p);
+ check_preempt_curr(rq, p);
success = 1;
out_running:
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) are cache-hot on their current CPU.
*/
- if (!cpu_isset(this_cpu, p->cpus_allowed))
+ if (!cpu_isset(this_cpu, p->cpus_allowed)) {
+ schedstat_inc(p, se.nr_failed_migrations_affine);
return 0;
+ }
*all_pinned = 0;
- if (task_running(rq, p))
+ if (task_running(rq, p)) {
+ schedstat_inc(p, se.nr_failed_migrations_running);
return 0;
+ }
+
+ /*
+ * Aggressive migration if:
+ * 1) task is cache cold, or
+ * 2) too many balance attempts have failed.
+ */
+
+ if (!task_hot(p, rq->clock, sd) ||
+ sd->nr_balance_failed > sd->cache_nice_tries) {
+#ifdef CONFIG_SCHEDSTATS
+ if (task_hot(p, rq->clock, sd)) {
+ schedstat_inc(sd, lb_hot_gained[idle]);
+ schedstat_inc(p, se.nr_forced_migrations);
+ }
+#endif
+ return 1;
+ }
+ if (task_hot(p, rq->clock, sd)) {
+ schedstat_inc(p, se.nr_failed_migrations_hot);
+ return 0;
+ }
return 1;
}
cpustat->user = cputime64_add(cpustat->user, tmp);
}
+/*
+ * Account guest cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in virtual machine since the last update
+ */
+void account_guest_time(struct task_struct *p, cputime_t cputime)
+{
+ cputime64_t tmp;
+ struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+
+ tmp = cputime_to_cputime64(cputime);
+
+ p->utime = cputime_add(p->utime, cputime);
+ p->gtime = cputime_add(p->gtime, cputime);
+
+ cpustat->user = cputime64_add(cpustat->user, tmp);
+ cpustat->guest = cputime64_add(cpustat->guest, tmp);
+}
+
/*
* Account system cpu time to a process.
* @p: the process that the cpu time gets accounted to
struct rq *rq = this_rq();
cputime64_t tmp;
+ if (p->flags & PF_VCPU) {
+ account_guest_time(p, cputime);
+ p->flags &= ~PF_VCPU;
+ return;
+ }
+
p->stime = cputime_add(p->stime, cputime);
/* Add system time to cpustat. */
}
#ifdef CONFIG_HOTPLUG_CPU
+
+static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
+{
+ int ret;
+
+ local_irq_disable();
+ ret = __migrate_task(p, src_cpu, dest_cpu);
+ local_irq_enable();
+ return ret;
+}
+
/*
* Figure out where task on dead CPU should go, use force if neccessary.
* NOTE: interrupts should be disabled by the caller
"longer affine to cpu%d\n",
p->pid, p->comm, dead_cpu);
}
- } while (!__migrate_task(p, dead_cpu, dest_cpu));
+ } while (!__migrate_task_irq(p, dead_cpu, dest_cpu));
}
/*
{
struct task_struct *p, *t;
- write_lock_irq(&tasklist_lock);
+ read_lock(&tasklist_lock);
do_each_thread(t, p) {
if (p == current)
move_task_off_dead_cpu(src_cpu, p);
} while_each_thread(t, p);
- write_unlock_irq(&tasklist_lock);
+ read_unlock(&tasklist_lock);
}
/*
* Drop lock around migration; if someone else moves it,
* that's OK. No task can be added to this CPU, so iteration is
* fine.
- * NOTE: interrupts should be left disabled --dev@
*/
- spin_unlock(&rq->lock);
+ spin_unlock_irq(&rq->lock);
move_task_off_dead_cpu(dead_cpu, p);
- spin_lock(&rq->lock);
+ spin_lock_irq(&rq->lock);
put_task_struct(p);
}
static struct ctl_table *sd_alloc_ctl_entry(int n)
{
struct ctl_table *entry =
- kmalloc(n * sizeof(struct ctl_table), GFP_KERNEL);
-
- BUG_ON(!entry);
- memset(entry, 0, n * sizeof(struct ctl_table));
+ kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
return entry;
}
+static void sd_free_ctl_entry(struct ctl_table **tablep)
+{
+ struct ctl_table *entry = *tablep;
+
+ for (entry = *tablep; entry->procname; entry++)
+ if (entry->child)
+ sd_free_ctl_entry(&entry->child);
+
+ kfree(*tablep);
+ *tablep = NULL;
+}
+
static void
set_table_entry(struct ctl_table *entry,
const char *procname, void *data, int maxlen,
{
struct ctl_table *table = sd_alloc_ctl_entry(12);
+ if (table == NULL)
+ return NULL;
+
set_table_entry(&table[0], "min_interval", &sd->min_interval,
sizeof(long), 0644, proc_doulongvec_minmax);
set_table_entry(&table[1], "max_interval", &sd->max_interval,
sizeof(int), 0644, proc_dointvec_minmax);
set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax);
+ /* &table[11] is terminator */
return table;
}
for_each_domain(cpu, sd)
domain_num++;
entry = table = sd_alloc_ctl_entry(domain_num + 1);
+ if (table == NULL)
+ return NULL;
i = 0;
for_each_domain(cpu, sd) {
}
static struct ctl_table_header *sd_sysctl_header;
-static void init_sched_domain_sysctl(void)
+static void register_sched_domain_sysctl(void)
{
int i, cpu_num = num_online_cpus();
struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
char buf[32];
+ if (entry == NULL)
+ return;
+
sd_ctl_dir[0].child = entry;
- for (i = 0; i < cpu_num; i++, entry++) {
+ for_each_online_cpu(i) {
snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
entry->mode = 0555;
entry->child = sd_alloc_ctl_cpu_table(i);
+ entry++;
}
sd_sysctl_header = register_sysctl_table(sd_ctl_root);
}
+
+static void unregister_sched_domain_sysctl(void)
+{
+ unregister_sysctl_table(sd_sysctl_header);
+ sd_sysctl_header = NULL;
+ sd_free_ctl_entry(&sd_ctl_dir[0].child);
+}
#else
-static void init_sched_domain_sysctl(void)
+static void register_sched_domain_sysctl(void)
+{
+}
+static void unregister_sched_domain_sysctl(void)
{
}
#endif
kthread_stop(rq->migration_thread);
rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
- rq = task_rq_lock(rq->idle, &flags);
+ spin_lock_irq(&rq->lock);
update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
- task_rq_unlock(rq, &flags);
+ spin_unlock_irq(&rq->lock);
migrate_nr_uninterruptible(rq);
BUG_ON(rq->nr_running != 0);
struct sched_group **sg)
{
int group;
- cpumask_t mask = cpu_sibling_map[cpu];
+ cpumask_t mask = per_cpu(cpu_sibling_map, cpu);
cpus_and(mask, mask, *cpu_map);
group = first_cpu(mask);
if (sg)
cpus_and(mask, mask, *cpu_map);
group = first_cpu(mask);
#elif defined(CONFIG_SCHED_SMT)
- cpumask_t mask = cpu_sibling_map[cpu];
+ cpumask_t mask = per_cpu(cpu_sibling_map, cpu);
cpus_and(mask, mask, *cpu_map);
group = first_cpu(mask);
#else
/*
* Allocate the per-node list of sched groups
*/
- sched_group_nodes = kzalloc(sizeof(struct sched_group *)*MAX_NUMNODES,
+ sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *),
GFP_KERNEL);
if (!sched_group_nodes) {
printk(KERN_WARNING "Can not alloc sched group node list\n");
p = sd;
sd = &per_cpu(cpu_domains, i);
*sd = SD_SIBLING_INIT;
- sd->span = cpu_sibling_map[i];
+ sd->span = per_cpu(cpu_sibling_map, i);
cpus_and(sd->span, sd->span, *cpu_map);
sd->parent = p;
p->child = sd;
#ifdef CONFIG_SCHED_SMT
/* Set up CPU (sibling) groups */
for_each_cpu_mask(i, *cpu_map) {
- cpumask_t this_sibling_map = cpu_sibling_map[i];
+ cpumask_t this_sibling_map = per_cpu(cpu_sibling_map, i);
cpus_and(this_sibling_map, this_sibling_map, *cpu_map);
if (i != first_cpu(this_sibling_map))
continue;
err = build_sched_domains(&cpu_default_map);
+ register_sched_domain_sysctl();
+
return err;
}
{
int i;
+ unregister_sched_domain_sysctl();
+
for_each_cpu_mask(i, *cpu_map)
cpu_attach_domain(NULL, i);
synchronize_sched();
arch_destroy_sched_domains(cpu_map);
}
-/*
- * Partition sched domains as specified by the cpumasks below.
- * This attaches all cpus from the cpumasks to the NULL domain,
- * waits for a RCU quiescent period, recalculates sched
- * domain information and then attaches them back to the
- * correct sched domains
- * Call with hotplug lock held
- */
-int partition_sched_domains(cpumask_t *partition1, cpumask_t *partition2)
-{
- cpumask_t change_map;
- int err = 0;
-
- cpus_and(*partition1, *partition1, cpu_online_map);
- cpus_and(*partition2, *partition2, cpu_online_map);
- cpus_or(change_map, *partition1, *partition2);
-
- /* Detach sched domains from all of the affected cpus */
- detach_destroy_domains(&change_map);
- if (!cpus_empty(*partition1))
- err = build_sched_domains(partition1);
- if (!err && !cpus_empty(*partition2))
- err = build_sched_domains(partition2);
-
- return err;
-}
-
#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
static int arch_reinit_sched_domains(void)
{
/* XXX: Theoretical race here - CPU may be hotplugged now */
hotcpu_notifier(update_sched_domains, 0);
- init_sched_domain_sysctl();
-
/* Move init over to a non-isolated CPU */
if (set_cpus_allowed(current, non_isolated_cpus) < 0)
BUG();
read_lock_irq(&tasklist_lock);
do_each_thread(g, p) {
+ /*
+ * Only normalize user tasks:
+ */
+ if (!p->mm)
+ continue;
+
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0;
spin_lock_irqsave(&p->pi_lock, flags);
rq = __task_rq_lock(p);
- if (!is_migration_thread(p, rq))
- normalize_task(rq, p);
+ normalize_task(rq, p);
__task_rq_unlock(rq);
spin_unlock_irqrestore(&p->pi_lock, flags);
if (tg->shares == shares)
goto done;
- /* return -EINVAL if the new value is not sane */
-
tg->shares = shares;
for_each_possible_cpu(i)
set_se_shares(tg->se[i], shares);
projects / linux-2.6 / blobdiff