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Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c9
-rw-r--r--kernel/smp.c4
-rw-r--r--kernel/smpboot.c72
-rw-r--r--kernel/smpboot.h2
4 files changed, 31 insertions, 56 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 05c46bae5e55..0e6353cf147a 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -297,15 +297,18 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
int ret, nr_calls = 0;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
+ struct task_struct *idle;
if (cpu_online(cpu) || !cpu_present(cpu))
return -EINVAL;
cpu_hotplug_begin();
- ret = smpboot_prepare(cpu);
- if (ret)
+ idle = idle_thread_get(cpu);
+ if (IS_ERR(idle)) {
+ ret = PTR_ERR(idle);
goto out;
+ }
ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
if (ret) {
@@ -316,7 +319,7 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
}
/* Arch-specific enabling code. */
- ret = __cpu_up(cpu, idle_thread_get(cpu));
+ ret = __cpu_up(cpu, idle);
if (ret != 0)
goto out_notify;
BUG_ON(!cpu_online(cpu));
diff --git a/kernel/smp.c b/kernel/smp.c
index 2f8b10ecf759..a61294c07f3f 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -13,6 +13,8 @@
#include <linux/smp.h>
#include <linux/cpu.h>
+#include "smpboot.h"
+
#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
static struct {
struct list_head queue;
@@ -669,6 +671,8 @@ void __init smp_init(void)
{
unsigned int cpu;
+ idle_threads_init();
+
/* FIXME: This should be done in userspace --RR */
for_each_present_cpu(cpu) {
if (num_online_cpus() >= setup_max_cpus)
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index ed1576981801..e1a797e028a3 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -6,64 +6,42 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/percpu.h>
-#include <linux/workqueue.h>
#include "smpboot.h"
#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
-struct create_idle {
- struct work_struct work;
- struct task_struct *idle;
- struct completion done;
- unsigned int cpu;
-};
-
-static void __cpuinit do_fork_idle(struct work_struct *work)
-{
- struct create_idle *c = container_of(work, struct create_idle, work);
-
- c->idle = fork_idle(c->cpu);
- complete(&c->done);
-}
-
-static struct task_struct * __cpuinit idle_thread_create(unsigned int cpu)
-{
- struct create_idle c_idle = {
- .cpu = cpu,
- .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
- };
-
- INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
- schedule_work(&c_idle.work);
- wait_for_completion(&c_idle.done);
- destroy_work_on_stack(&c_idle.work);
- return c_idle.idle;
-}
-
/*
* For the hotplug case we keep the task structs around and reuse
* them.
*/
static DEFINE_PER_CPU(struct task_struct *, idle_threads);
-static inline struct task_struct *get_idle_for_cpu(unsigned int cpu)
+struct task_struct * __cpuinit idle_thread_get(unsigned int cpu)
{
struct task_struct *tsk = per_cpu(idle_threads, cpu);
if (!tsk)
- return idle_thread_create(cpu);
+ return ERR_PTR(-ENOMEM);
init_idle(tsk, cpu);
return tsk;
}
-struct task_struct * __cpuinit idle_thread_get(unsigned int cpu)
+void __init idle_thread_set_boot_cpu(void)
{
- return per_cpu(idle_threads, cpu);
+ per_cpu(idle_threads, smp_processor_id()) = current;
}
-void __init idle_thread_set_boot_cpu(void)
+static inline void idle_init(unsigned int cpu)
{
- per_cpu(idle_threads, smp_processor_id()) = current;
+ struct task_struct *tsk = per_cpu(idle_threads, cpu);
+
+ if (!tsk) {
+ tsk = fork_idle(cpu);
+ if (IS_ERR(tsk))
+ pr_err("SMP: fork_idle() failed for CPU %u\n", cpu);
+ else
+ per_cpu(idle_threads, cpu) = tsk;
+ }
}
/**
@@ -72,25 +50,13 @@ void __init idle_thread_set_boot_cpu(void)
*
* Creates the thread if it does not exist.
*/
-static int __cpuinit idle_thread_init(unsigned int cpu)
+void __init idle_threads_init(void)
{
- struct task_struct *idle = get_idle_for_cpu(cpu);
+ unsigned int cpu;
- if (IS_ERR(idle)) {
- printk(KERN_ERR "failed fork for CPU %u\n", cpu);
- return PTR_ERR(idle);
+ for_each_possible_cpu(cpu) {
+ if (cpu != smp_processor_id())
+ idle_init(cpu);
}
- per_cpu(idle_threads, cpu) = idle;
- return 0;
}
-#else
-static inline int idle_thread_init(unsigned int cpu) { return 0; }
#endif
-
-/**
- * smpboot_prepare - generic smpboot preparation
- */
-int __cpuinit smpboot_prepare(unsigned int cpu)
-{
- return idle_thread_init(cpu);
-}
diff --git a/kernel/smpboot.h b/kernel/smpboot.h
index 7943bbbab917..4cfbcb8a8362 100644
--- a/kernel/smpboot.h
+++ b/kernel/smpboot.h
@@ -8,9 +8,11 @@ int smpboot_prepare(unsigned int cpu);
#ifdef CONFIG_GENERIC_SMP_IDLE_THREAD
struct task_struct *idle_thread_get(unsigned int cpu);
void idle_thread_set_boot_cpu(void);
+void idle_threads_init(void);
#else
static inline struct task_struct *idle_thread_get(unsigned int cpu) { return NULL; }
static inline void idle_thread_set_boot_cpu(void) { }
+static inline void idle_threads_init(unsigned int cpu) { }
#endif
#endif