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powerpc: 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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: http://lkml.kernel.org/r/20120420124557.311212868@linutronix.de
This commit is contained in:
Thomas Gleixner 2012-04-20 13:05:48 +00:00
parent 7eb43a6d23
commit 17e32eacc3
2 changed files with 6 additions and 69 deletions
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1
arch/powerpc/Kconfig
View File

@ -144,6 +144,7 @@ config PPC
select HAVE_BPF_JIT if (PPC64 && NET)
select HAVE_ARCH_JUMP_LABEL
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_SMP_IDLE_THREAD
config EARLY_PRINTK
bool

74
arch/powerpc/kernel/smp.c
View File

@ -57,27 +57,9 @@
#define DBG(fmt...)
#endif
/* 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))
/* State of each CPU during hotplug phases */
static DEFINE_PER_CPU(int, cpu_state) = { 0 };
#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
struct thread_info *secondary_ti;
@ -429,57 +411,16 @@ int generic_check_cpu_restart(unsigned int cpu)
}
#endif
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)
static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
{
struct create_idle *c_idle =
container_of(work, struct create_idle, work);
c_idle->idle = fork_idle(c_idle->cpu);
complete(&c_idle->done);
}
static int __cpuinit create_idle(unsigned int cpu)
{
struct thread_info *ti;
struct create_idle c_idle = {
.cpu = cpu,
.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
};
INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
c_idle.idle = get_idle_for_cpu(cpu);
/* We can't use kernel_thread since we must avoid to
* reschedule the child. We use a workqueue because
* we want to fork from a kernel thread, not whatever
* userspace process happens to be trying to online us.
*/
if (!c_idle.idle) {
schedule_work(&c_idle.work);
wait_for_completion(&c_idle.done);
} else
init_idle(c_idle.idle, cpu);
if (IS_ERR(c_idle.idle)) {
pr_err("Failed fork for CPU %u: %li", cpu, PTR_ERR(c_idle.idle));
return PTR_ERR(c_idle.idle);
}
ti = task_thread_info(c_idle.idle);
struct thread_info *ti = task_thread_info(idle);
#ifdef CONFIG_PPC64
paca[cpu].__current = c_idle.idle;
paca[cpu].__current = idle;
paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
#endif
ti->cpu = cpu;
current_set[cpu] = ti;
return 0;
secondary_ti = current_set[cpu] = ti;
}
int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
@ -490,12 +431,7 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
(smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
return -EINVAL;
/* Make sure we have an idle thread */
rc = create_idle(cpu);
if (rc)
return rc;
secondary_ti = current_set[cpu];
cpu_idle_thread_init(cpu, tidle);
/* Make sure callin-map entry is 0 (can be leftover a CPU
* hotplug