Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp hotplug cleanups from Thomas Gleixner:
 "This series is merily a cleanup of code copied around in arch/* and
  not changing any of the real cpu hotplug horrors yet.  I wish I'd had
  something more substantial for 3.5, but I underestimated the lurking
  horror..."

Fix up trivial conflicts in arch/{arm,sparc,x86}/Kconfig and
arch/sparc/include/asm/thread_info_32.h

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
  um: Remove leftover declaration of alloc_task_struct_node()
  task_allocator: Use config switches instead of magic defines
  sparc: Use common threadinfo allocator
  score: Use common threadinfo allocator
  sh-use-common-threadinfo-allocator
  mn10300: Use common threadinfo allocator
  powerpc: Use common threadinfo allocator
  mips: Use common threadinfo allocator
  hexagon: Use common threadinfo allocator
  m32r: Use common threadinfo allocator
  frv: Use common threadinfo allocator
  cris: Use common threadinfo allocator
  x86: Use common threadinfo allocator
  c6x: Use common threadinfo allocator
  fork: Provide kmemcache based thread_info allocator
  tile: Use common threadinfo allocator
  fork: Provide weak arch_release_[task_struct|thread_info] functions
  fork: Move thread info gfp flags to header
  fork: Remove the weak insanity
  sh: Remove cpu_idle_wait()
  ...

1 files changed, 6 insertions, 70 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index d9f94410fd7f..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;
@@ -429,60 +411,19 @@ 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)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	int rc, c;
 
@@ -490,12 +431,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	    (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