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x86: use create_idle struct in do_boot_cpu 

Use a new worker, with help of the create_idle struct
to fork the idle thread. We now have two workers, the first
of them triggered by __smp_prepare_cpu. But the later is
going away soon.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Glauber de Oliveira Costa 2008-03-19 14:25:45 -03:00 committed by Ingo Molnar
parent ddd10ecfa2
commit 365c894c65
1 changed files with 59 additions and 27 deletions
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86
arch/x86/kernel/smpboot_32.c
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@ -79,6 +79,24 @@ static void map_cpu_to_logical_apicid(void);
/* State of each CPU. */
DEFINE_PER_CPU(int, cpu_state) = { 0 };
/* Store all idle threads, this can be reused instead of creating
* a new thread. Also avoids complicated thread destroy functionality
* for idle threads.
*/
#ifdef CONFIG_HOTPLUG_CPU
/*
* Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
* removed after init for !CONFIG_HOTPLUG_CPU.
*/
static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
#define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
#define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
#else
struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
#define get_idle_for_cpu(x) (idle_thread_array[(x)])
#define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
#endif
static atomic_t init_deasserted;
static void __cpuinit smp_callin(void)
@ -513,30 +531,21 @@ wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
extern cpumask_t cpu_initialized;
#ifdef CONFIG_HOTPLUG_CPU
static struct task_struct * __cpuinitdata cpu_idle_tasks[NR_CPUS];
static inline struct task_struct * __cpuinit alloc_idle_task(int cpu)
{
struct create_idle {
struct work_struct work;
struct task_struct *idle;
struct completion done;
int cpu;
};
if ((idle = cpu_idle_tasks[cpu]) != NULL) {
/* initialize thread_struct. we really want to avoid destroy
* idle tread
*/
idle->thread.sp = (unsigned long)task_pt_regs(idle);
init_idle(idle, cpu);
return idle;
}
idle = fork_idle(cpu);
static void __cpuinit do_fork_idle(struct work_struct *work)
{
struct create_idle *c_idle =
container_of(work, struct create_idle, work);
if (!IS_ERR(idle))
cpu_idle_tasks[cpu] = idle;
return idle;
c_idle->idle = fork_idle(c_idle->cpu);
complete(&c_idle->done);
}
#else
#define alloc_idle_task(cpu) fork_idle(cpu)
#endif
static int __cpuinit do_boot_cpu(int apicid, int cpu)
/*
* NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
@ -544,11 +553,15 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
* Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
*/
{
struct task_struct *idle;
unsigned long boot_error;
int timeout;
unsigned long start_eip;
unsigned short nmi_high = 0, nmi_low = 0;
struct create_idle c_idle = {
.cpu = cpu,
.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
};
INIT_WORK(&c_idle.work, do_fork_idle);
/*
* Save current MTRR state in case it was changed since early boot
@ -556,19 +569,38 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
*/
mtrr_save_state();
c_idle.idle = get_idle_for_cpu(cpu);
/*
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
idle = alloc_idle_task(cpu);
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
if (c_idle.idle) {
c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
(THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
init_idle(c_idle.idle, cpu);
goto do_rest;
}
if (!keventd_up() || current_is_keventd())
c_idle.work.func(&c_idle.work);
else {
schedule_work(&c_idle.work);
wait_for_completion(&c_idle.done);
}
if (IS_ERR(c_idle.idle)) {
printk(KERN_ERR "failed fork for CPU %d\n", cpu);
return PTR_ERR(c_idle.idle);
}
set_idle_for_cpu(cpu, c_idle.idle);
do_rest:
per_cpu(current_task, cpu) = c_idle.idle;
init_gdt(cpu);
per_cpu(current_task, cpu) = idle;
early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
idle->thread.ip = (unsigned long) start_secondary;
c_idle.idle->thread.ip = (unsigned long) start_secondary;
/* start_eip had better be page-aligned! */
start_eip = setup_trampoline();
@ -577,7 +609,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
/* So we see what's up */
printk("Booting processor %d/%d ip %lx\n", cpu, apicid, start_eip);
/* Stack for startup_32 can be just as for start_secondary onwards */
stack_start.sp = (void *) idle->thread.sp;
stack_start.sp = (void *) c_idle.idle->thread.sp;
irq_ctx_init(cpu);