aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--arch/ia64/include/asm/topology.h5
-rw-r--r--arch/mips/include/asm/mach-ip27/topology.h2
-rw-r--r--arch/powerpc/include/asm/topology.h5
-rw-r--r--arch/sh/include/asm/topology.h4
-rw-r--r--arch/sparc/include/asm/topology_64.h4
-rw-r--r--arch/x86/include/asm/topology.h4
-rw-r--r--include/linux/sched.h7
-rw-r--r--include/linux/topology.h16
-rw-r--r--kernel/sched.c41
-rw-r--r--kernel/sched_fair.c233
10 files changed, 84 insertions, 237 deletions
diff --git a/arch/ia64/include/asm/topology.h b/arch/ia64/include/asm/topology.h
index 7b4c8c70b2d..cf6053b226c 100644
--- a/arch/ia64/include/asm/topology.h
+++ b/arch/ia64/include/asm/topology.h
@@ -67,6 +67,7 @@ void build_cpu_to_node_map(void);
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_NEWIDLE \
| SD_BALANCE_EXEC \
+ | SD_BALANCE_WAKE \
| SD_WAKE_AFFINE, \
.last_balance = jiffies, \
.balance_interval = 1, \
@@ -91,8 +92,8 @@ void build_cpu_to_node_map(void);
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
| SD_BALANCE_FORK \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_BALANCE_WAKE \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 64, \
.nr_balance_failed = 0, \
diff --git a/arch/mips/include/asm/mach-ip27/topology.h b/arch/mips/include/asm/mach-ip27/topology.h
index 07547231e07..d8332398f5b 100644
--- a/arch/mips/include/asm/mach-ip27/topology.h
+++ b/arch/mips/include/asm/mach-ip27/topology.h
@@ -48,7 +48,7 @@ extern unsigned char __node_distances[MAX_COMPACT_NODES][MAX_COMPACT_NODES];
.cache_nice_tries = 1, \
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
- | SD_WAKE_BALANCE, \
+ | SD_BALANCE_WAKE, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index 054a16d6808..c6343313ff5 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -62,9 +62,8 @@ static inline int pcibus_to_node(struct pci_bus *bus)
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_EXEC \
| SD_BALANCE_NEWIDLE \
- | SD_WAKE_IDLE \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_BALANCE_WAKE \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff --git a/arch/sh/include/asm/topology.h b/arch/sh/include/asm/topology.h
index b69ee850906..dc1531e2f25 100644
--- a/arch/sh/include/asm/topology.h
+++ b/arch/sh/include/asm/topology.h
@@ -21,8 +21,8 @@
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_FORK \
| SD_BALANCE_EXEC \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_BALANCE_WAKE \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
.nr_balance_failed = 0, \
diff --git a/arch/sparc/include/asm/topology_64.h b/arch/sparc/include/asm/topology_64.h
index e5ea8d33242..1d091abd2d1 100644
--- a/arch/sparc/include/asm/topology_64.h
+++ b/arch/sparc/include/asm/topology_64.h
@@ -57,8 +57,8 @@ static inline int pcibus_to_node(struct pci_bus *pbus)
.flags = SD_LOAD_BALANCE \
| SD_BALANCE_FORK \
| SD_BALANCE_EXEC \
- | SD_SERIALIZE \
- | SD_WAKE_BALANCE, \
+ | SD_BALANCE_WAKE \
+ | SD_SERIALIZE, \
.last_balance = jiffies, \
.balance_interval = 1, \
}
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 26d06e052a1..966d58dc627 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -145,14 +145,12 @@ extern unsigned long node_remap_size[];
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 0*SD_WAKE_IDLE \
+ | 1*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
| 0*SD_SHARE_PKG_RESOURCES \
| 1*SD_SERIALIZE \
- | 1*SD_WAKE_IDLE_FAR \
| 0*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3b0ca66bd6c..c30bf3d516d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -803,16 +803,15 @@ enum cpu_idle_type {
#define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */
#define SD_BALANCE_EXEC 0x0004 /* Balance on exec */
#define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
-#define SD_WAKE_IDLE 0x0010 /* Wake to idle CPU on task wakeup */
+#define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
#define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
-#define SD_WAKE_BALANCE 0x0040 /* Perform balancing at task wakeup */
+
#define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power */
#define SD_POWERSAVINGS_BALANCE 0x0100 /* Balance for power savings */
#define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
-#define SD_WAKE_IDLE_FAR 0x0800 /* Gain latency sacrificing cache hit */
+
#define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
-#define SD_BALANCE_WAKE 0x2000 /* Balance on wakeup */
enum powersavings_balance_level {
POWERSAVINGS_BALANCE_NONE = 0, /* No power saving load balance */
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 85e8cf7d393..6a8cd15555b 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -95,14 +95,12 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 0*SD_WAKE_IDLE \
+ | 1*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
| 1*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
- | 0*SD_WAKE_IDLE_FAR \
| 0*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
@@ -129,13 +127,11 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 1*SD_WAKE_IDLE \
+ | 1*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
| 0*SD_SHARE_CPUPOWER \
| 1*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
- | 0*SD_WAKE_IDLE_FAR \
| sd_balance_for_mc_power() \
| sd_power_saving_flags() \
, \
@@ -163,13 +159,11 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_NEWIDLE \
| 1*SD_BALANCE_EXEC \
| 1*SD_BALANCE_FORK \
- | 1*SD_WAKE_IDLE \
+ | 1*SD_BALANCE_WAKE \
| 0*SD_WAKE_AFFINE \
- | 1*SD_WAKE_BALANCE \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
- | 0*SD_WAKE_IDLE_FAR \
| sd_balance_for_package_power() \
| sd_power_saving_flags() \
, \
@@ -191,14 +185,12 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_NEWIDLE \
| 0*SD_BALANCE_EXEC \
| 0*SD_BALANCE_FORK \
- | 0*SD_WAKE_IDLE \
+ | 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 0*SD_WAKE_BALANCE \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_POWERSAVINGS_BALANCE \
| 0*SD_SHARE_PKG_RESOURCES \
| 1*SD_SERIALIZE \
- | 1*SD_WAKE_IDLE_FAR \
| 0*SD_PREFER_SIBLING \
, \
.last_balance = jiffies, \
diff --git a/kernel/sched.c b/kernel/sched.c
index fc6fda881d2..6c819f338b1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -512,14 +512,6 @@ struct root_domain {
#ifdef CONFIG_SMP
struct cpupri cpupri;
#endif
-#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
- /*
- * Preferred wake up cpu nominated by sched_mc balance that will be
- * used when most cpus are idle in the system indicating overall very
- * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
- */
- unsigned int sched_mc_preferred_wakeup_cpu;
-#endif
};
/*
@@ -2315,22 +2307,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
-#ifdef CONFIG_SMP
- if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) {
- struct sched_domain *sd;
-
- this_cpu = raw_smp_processor_id();
- cpu = task_cpu(p);
-
- for_each_domain(this_cpu, sd) {
- if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
- update_shares(sd);
- break;
- }
- }
- }
-#endif
-
this_cpu = get_cpu();
smp_wmb();
@@ -3533,11 +3509,6 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
*imbalance = sds->min_load_per_task;
sds->busiest = sds->group_min;
- if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) {
- cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu =
- group_first_cpu(sds->group_leader);
- }
-
return 1;
}
@@ -7850,9 +7821,7 @@ static int sd_degenerate(struct sched_domain *sd)
}
/* Following flags don't use groups */
- if (sd->flags & (SD_WAKE_IDLE |
- SD_WAKE_AFFINE |
- SD_WAKE_BALANCE))
+ if (sd->flags & (SD_WAKE_AFFINE))
return 0;
return 1;
@@ -7869,10 +7838,6 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
return 0;
- /* Does parent contain flags not in child? */
- /* WAKE_BALANCE is a subset of WAKE_AFFINE */
- if (cflags & SD_WAKE_AFFINE)
- pflags &= ~SD_WAKE_BALANCE;
/* Flags needing groups don't count if only 1 group in parent */
if (parent->groups == parent->groups->next) {
pflags &= ~(SD_LOAD_BALANCE |
@@ -8558,10 +8523,10 @@ static void set_domain_attribute(struct sched_domain *sd,
request = attr->relax_domain_level;
if (request < sd->level) {
/* turn off idle balance on this domain */
- sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE);
+ sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
} else {
/* turn on idle balance on this domain */
- sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
+ sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
}
}
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index f2eb5b93471..09d19f77eb3 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1062,83 +1062,6 @@ static void yield_task_fair(struct rq *rq)
se->vruntime = rightmost->vruntime + 1;
}
-/*
- * wake_idle() will wake a task on an idle cpu if task->cpu is
- * not idle and an idle cpu is available. The span of cpus to
- * search starts with cpus closest then further out as needed,
- * so we always favor a closer, idle cpu.
- * Domains may include CPUs that are not usable for migration,
- * hence we need to mask them out (rq->rd->online)
- *
- * Returns the CPU we should wake onto.
- */
-#if defined(ARCH_HAS_SCHED_WAKE_IDLE)
-
-#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online)
-
-static int wake_idle(int cpu, struct task_struct *p)
-{
- struct sched_domain *sd;
- int i;
- unsigned int chosen_wakeup_cpu;
- int this_cpu;
- struct rq *task_rq = task_rq(p);
-
- /*
- * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu
- * are idle and this is not a kernel thread and this task's affinity
- * allows it to be moved to preferred cpu, then just move!
- */
-
- this_cpu = smp_processor_id();
- chosen_wakeup_cpu =
- cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu;
-
- if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP &&
- idle_cpu(cpu) && idle_cpu(this_cpu) &&
- p->mm && !(p->flags & PF_KTHREAD) &&
- cpu_isset(chosen_wakeup_cpu, p->cpus_allowed))
- return chosen_wakeup_cpu;
-
- /*
- * If it is idle, then it is the best cpu to run this task.
- *
- * This cpu is also the best, if it has more than one task already.
- * Siblings must be also busy(in most cases) as they didn't already
- * pickup the extra load from this cpu and hence we need not check
- * sibling runqueue info. This will avoid the checks and cache miss
- * penalities associated with that.
- */
- if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1)
- return cpu;
-
- for_each_domain(cpu, sd) {
- if ((sd->flags & SD_WAKE_IDLE)
- || ((sd->flags & SD_WAKE_IDLE_FAR)
- && !task_hot(p, task_rq->clock, sd))) {
- for_each_cpu_and(i, sched_domain_span(sd),
- &p->cpus_allowed) {
- if (cpu_rd_active(i, task_rq) && idle_cpu(i)) {
- if (i != task_cpu(p)) {
- schedstat_inc(p,
- se.nr_wakeups_idle);
- }
- return i;
- }
- }
- } else {
- break;
- }
- }
- return cpu;
-}
-#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/
-static inline int wake_idle(int cpu, struct task_struct *p)
-{
- return cpu;
-}
-#endif
-
#ifdef CONFIG_SMP
#ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1225,21 +1148,22 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu,
#endif
-static int
-wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
- struct task_struct *p, int prev_cpu, int this_cpu, int sync,
- int idx, unsigned long load, unsigned long this_load,
- unsigned int imbalance)
+static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
{
- struct task_struct *curr = this_rq->curr;
- struct task_group *tg;
- unsigned long tl = this_load;
+ struct task_struct *curr = current;
+ unsigned long this_load, load;
+ int idx, this_cpu, prev_cpu;
unsigned long tl_per_task;
+ unsigned int imbalance;
+ struct task_group *tg;
unsigned long weight;
int balanced;
- if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
- return 0;
+ idx = sd->wake_idx;
+ this_cpu = smp_processor_id();
+ prev_cpu = task_cpu(p);
+ load = source_load(prev_cpu, idx);
+ this_load = target_load(this_cpu, idx);
if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost ||
p->se.avg_overlap > sysctl_sched_migration_cost))
@@ -1254,24 +1178,26 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
tg = task_group(current);
weight = current->se.load.weight;
- tl += effective_load(tg, this_cpu, -weight, -weight);
+ this_load += effective_load(tg, this_cpu, -weight, -weight);
load += effective_load(tg, prev_cpu, 0, -weight);
}
tg = task_group(p);
weight = p->se.load.weight;
+ imbalance = 100 + (sd->imbalance_pct - 100) / 2;
+
/*
* In low-load situations, where prev_cpu is idle and this_cpu is idle
- * due to the sync cause above having dropped tl to 0, we'll always have
- * an imbalance, but there's really nothing you can do about that, so
- * that's good too.
+ * due to the sync cause above having dropped this_load to 0, we'll
+ * always have an imbalance, but there's really nothing you can do
+ * about that, so that's good too.
*
* Otherwise check if either cpus are near enough in load to allow this
* task to be woken on this_cpu.
*/
- balanced = !tl ||
- 100*(tl + effective_load(tg, this_cpu, weight, weight)) <=
+ balanced = !this_load ||
+ 100*(this_load + effective_load(tg, this_cpu, weight, weight)) <=
imbalance*(load + effective_load(tg, prev_cpu, 0, weight));
/*
@@ -1285,14 +1211,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
- if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <=
- tl_per_task)) {
+ if (balanced ||
+ (this_load <= load &&
+ this_load + target_load(prev_cpu, idx) <= tl_per_task)) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
* there is no bad imbalance.
*/
- schedstat_inc(this_sd, ttwu_move_affine);
+ schedstat_inc(sd, ttwu_move_affine);
schedstat_inc(p, se.nr_wakeups_affine);
return 1;
@@ -1300,72 +1227,6 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
return 0;
}
-static int sched_balance_self(int cpu, int flag);
-
-static int select_task_rq_fair(struct task_struct *p, int flag, int sync)
-{
- struct sched_domain *sd, *this_sd = NULL;
- int prev_cpu, this_cpu, new_cpu;
- unsigned long load, this_load;
- struct rq *this_rq;
- unsigned int imbalance;
- int idx;
-
- prev_cpu = task_cpu(p);
- this_cpu = smp_processor_id();
- this_rq = cpu_rq(this_cpu);
- new_cpu = prev_cpu;
-
- if (flag != SD_BALANCE_WAKE)
- return sched_balance_self(this_cpu, flag);
-
- /*
- * 'this_sd' is the first domain that both
- * this_cpu and prev_cpu are present in:
- */
- for_each_domain(this_cpu, sd) {
- if (cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) {
- this_sd = sd;
- break;
- }
- }
-
- if (unlikely(!cpumask_test_cpu(this_cpu, &p->cpus_allowed)))
- goto out;
-
- /*
- * Check for affine wakeup and passive balancing possibilities.
- */
- if (!this_sd)
- goto out;
-
- idx = this_sd->wake_idx;
-
- imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
-
- load = source_load(prev_cpu, idx);
- this_load = target_load(this_cpu, idx);
-
- if (wake_affine(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,
- load, this_load, imbalance))
- return this_cpu;
-
- /*
- * Start passive balancing when half the imbalance_pct
- * limit is reached.
- */
- 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);
- return this_cpu;
- }
- }
-
-out:
- return wake_idle(new_cpu, p);
-}
-
/*
* find_idlest_group finds and returns the least busy CPU group within the
* domain.
@@ -1455,10 +1316,20 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
*
* preempt must be disabled.
*/
-static int sched_balance_self(int cpu, int flag)
+static int select_task_rq_fair(struct task_struct *p, int flag, int sync)
{
struct task_struct *t = current;
struct sched_domain *tmp, *sd = NULL;
+ int cpu = smp_processor_id();
+ int prev_cpu = task_cpu(p);
+ int new_cpu = cpu;
+ int want_affine = 0;
+
+ if (flag & SD_BALANCE_WAKE) {
+ if (sched_feat(AFFINE_WAKEUPS))
+ want_affine = 1;
+ new_cpu = prev_cpu;
+ }
for_each_domain(cpu, tmp) {
/*
@@ -1466,16 +1337,38 @@ static int sched_balance_self(int cpu, int flag)
*/
if (tmp->flags & SD_POWERSAVINGS_BALANCE)
break;
- if (tmp->flags & flag)
- sd = tmp;
- }
- if (sd)
- update_shares(sd);
+ switch (flag) {
+ case SD_BALANCE_WAKE:
+ if (!sched_feat(LB_WAKEUP_UPDATE))
+ break;
+ case SD_BALANCE_FORK:
+ case SD_BALANCE_EXEC:
+ if (root_task_group_empty())
+ break;
+ update_shares(tmp);
+ default:
+ break;
+ }
+
+ if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
+ cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
+
+ if (wake_affine(tmp, p, sync))
+ return cpu;
+
+ want_affine = 0;
+ }
+
+ if (!(tmp->flags & flag))
+ continue;
+
+ sd = tmp;
+ }
while (sd) {
struct sched_group *group;
- int new_cpu, weight;
+ int weight;
if (!(sd->flags & flag)) {
sd = sd->child;
@@ -1508,7 +1401,7 @@ static int sched_balance_self(int cpu, int flag)
/* while loop will break here if sd == NULL */
}
- return cpu;
+ return new_cpu;
}
#endif /* CONFIG_SMP */