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x86: Use generic idle thread allocation 

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124557.246929343@linutronix.de
This commit is contained in:
Thomas Gleixner 2012-04-20 13:05:48 +00:00
parent 5cdaf1834f
commit 7eb43a6d23
4 changed files with 14 additions and 84 deletions
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1
arch/x86/Kconfig
View File

@ -82,6 +82,7 @@ config X86
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_IOMAP
select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
select GENERIC_SMP_IDLE_THREAD
config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)

1
arch/x86/include/asm/smp.h
View File

@ -164,6 +164,7 @@ int wbinvd_on_all_cpus(void);
void native_send_call_func_ipi(const struct cpumask *mask);
void native_send_call_func_single_ipi(int cpu);
void x86_idle_thread_init(unsigned int cpu, struct task_struct *idle);
void smp_store_cpu_info(int id);
#define cpu_physical_id(cpu) per_cpu(x86_cpu_to_apicid, cpu)

81
arch/x86/kernel/smpboot.c
View File

@ -76,19 +76,7 @@
/* 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))
/*
* We need this for trampoline_base protection from concurrent accesses when
* off- and onlining cores wildly.
@ -97,20 +85,16 @@ static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex);
void cpu_hotplug_driver_lock(void)
{
mutex_lock(&x86_cpu_hotplug_driver_mutex);
mutex_lock(&x86_cpu_hotplug_driver_mutex);
}
void cpu_hotplug_driver_unlock(void)
{
mutex_unlock(&x86_cpu_hotplug_driver_mutex);
mutex_unlock(&x86_cpu_hotplug_driver_mutex);
}
ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; }
ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; }
#else
static 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
/* Number of siblings per CPU package */
@ -618,22 +602,6 @@ wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
return (send_status | accept_status);
}
struct create_idle {
struct work_struct work;
struct task_struct *idle;
struct completion done;
int cpu;
};
static void __cpuinit do_fork_idle(struct work_struct *work)
{
struct create_idle *c_idle =
container_of(work, struct create_idle, work);
c_idle->idle = fork_idle(c_idle->cpu);
complete(&c_idle->done);
}
/* reduce the number of lines printed when booting a large cpu count system */
static void __cpuinit announce_cpu(int cpu, int apicid)
{
@ -660,58 +628,31 @@ static void __cpuinit announce_cpu(int cpu, int apicid)
* Returns zero if CPU booted OK, else error code from
* ->wakeup_secondary_cpu.
*/
static int __cpuinit do_boot_cpu(int apicid, int cpu)
static int __cpuinit do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
{
unsigned long boot_error = 0;
unsigned long start_ip;
int timeout;
struct create_idle c_idle = {
.cpu = cpu,
.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
};
INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
alternatives_smp_switch(1);
c_idle.idle = get_idle_for_cpu(cpu);
idle->thread.sp = (unsigned long) (((struct pt_regs *)
(THREAD_SIZE + task_stack_page(idle))) - 1);
per_cpu(current_task, cpu) = idle;
/*
* We can't use kernel_thread since we must avoid to
* reschedule the child.
*/
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;
}
schedule_work(&c_idle.work);
wait_for_completion(&c_idle.done);
if (IS_ERR(c_idle.idle)) {
printk("failed fork for CPU %d\n", cpu);
destroy_work_on_stack(&c_idle.work);
return PTR_ERR(c_idle.idle);
}
set_idle_for_cpu(cpu, c_idle.idle);
do_rest:
per_cpu(current_task, cpu) = c_idle.idle;
#ifdef CONFIG_X86_32
/* Stack for startup_32 can be just as for start_secondary onwards */
irq_ctx_init(cpu);
#else
clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
clear_tsk_thread_flag(idle, TIF_FORK);
initial_gs = per_cpu_offset(cpu);
per_cpu(kernel_stack, cpu) =
(unsigned long)task_stack_page(c_idle.idle) -
(unsigned long)task_stack_page(idle) -
KERNEL_STACK_OFFSET + THREAD_SIZE;
#endif
early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
initial_code = (unsigned long)start_secondary;
stack_start = c_idle.idle->thread.sp;
stack_start = idle->thread.sp;
/* start_ip had better be page-aligned! */
start_ip = trampoline_address();
@ -813,8 +754,6 @@ do_rest:
*/
smpboot_restore_warm_reset_vector();
}
destroy_work_on_stack(&c_idle.work);
return boot_error;
}
@ -851,7 +790,7 @@ int __cpuinit native_cpu_up(unsigned int cpu, struct task_struct *tidle)
per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
err = do_boot_cpu(apicid, cpu);
err = do_boot_cpu(apicid, cpu, tidle);
if (err) {
pr_debug("do_boot_cpu failed %d\n", err);
return -EIO;

15
arch/x86/xen/smp.c
View File

@ -250,18 +250,8 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
set_cpu_possible(cpu, false);
}
for_each_possible_cpu (cpu) {
struct task_struct *idle;
if (cpu == 0)
continue;
idle = fork_idle(cpu);
if (IS_ERR(idle))
panic("failed fork for CPU %d", cpu);
for_each_possible_cpu(cpu)
set_cpu_present(cpu, true);
}
}
static int __cpuinit
@ -331,9 +321,8 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
return 0;
}
static int __cpuinit xen_cpu_up(unsigned int cpu, struct task_struct *tidle)
static int __cpuinit xen_cpu_up(unsigned int cpu, struct task_struct *idle)
{
struct task_struct *idle = idle_task(cpu);
int rc;
per_cpu(current_task, cpu) = idle;