From 17e32eacc3543c25a4377bb7ce54026e38db7d20 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 20 Apr 2012 13:05:48 +0000 Subject: [PATCH] powerpc: Use generic idle thread allocation Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Rusty Russell Cc: Paul E. McKenney Cc: Srivatsa S. Bhat Cc: Benjamin Herrenschmidt Link: http://lkml.kernel.org/r/20120420124557.311212868@linutronix.de --- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/smp.c | 74 +++------------------------------------ 2 files changed, 6 insertions(+), 69 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index feab3bad6d0f..c81553508366 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -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 diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index d38030fb3471..e4cb34322de4 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -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