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()
  ...

arch/ia64/Kconfig

@@ -33,6 +33,10 @@ config IA64
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_IOMAP
+	select GENERIC_SMP_IDLE_THREAD
+	select ARCH_INIT_TASK
+	select ARCH_TASK_STRUCT_ALLOCATOR
+	select ARCH_THREAD_INFO_ALLOCATOR
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to

arch/ia64/include/asm/processor.h

@@ -723,7 +723,6 @@ extern unsigned long boot_option_idle_override;
 enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_FORCE_MWAIT,
 			 IDLE_NOMWAIT, IDLE_POLL};
 
-void cpu_idle_wait(void);
 void default_idle(void);
 
 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)

arch/ia64/include/asm/thread_info.h

@@ -54,8 +54,6 @@ struct thread_info {
 	},					\
 }
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
 #ifndef ASM_OFFSETS_C
 /* how to get the thread information struct from C */
 #define current_thread_info()	((struct thread_info *) ((char *) current + IA64_TASK_SIZE))
@@ -84,7 +82,6 @@ struct thread_info {
 #endif
 #define end_of_stack(p) (unsigned long *)((void *)(p) + IA64_RBS_OFFSET)
 
-#define __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
 #define alloc_task_struct_node(node)						\
 ({										\
 	struct page *page = alloc_pages_node(node, GFP_KERNEL | __GFP_COMP,	\

arch/ia64/kernel/process.c

@@ -273,26 +273,6 @@ static inline void play_dead(void)
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static void do_nothing(void *unused)
-{
-}
-
-/*
- * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
- * pm_idle and update to new pm_idle value. Required while changing pm_idle
- * handler on SMP systems.
- *
- * Caller must have changed pm_idle to the new value before the call. Old
- * pm_idle value will not be used by any CPU after the return of this function.
- */
-void cpu_idle_wait(void)
-{
-	smp_mb();
-	/* kick all the CPUs so that they exit out of pm_idle */
-	smp_call_function(do_nothing, NULL, 1);
-}
-EXPORT_SYMBOL_GPL(cpu_idle_wait);
-
 void __attribute__((noreturn))
 cpu_idle (void)
 {

arch/ia64/kernel/smpboot.c

@@ -74,13 +74,6 @@
 #define bsp_remove_ok	0
 #endif
 
-/*
- * Store all idle threads, this can be reused instead of creating
- * a new thread. Also avoids complicated thread destroy functionality
- * for idle threads.
- */
-struct task_struct *idle_thread_array[NR_CPUS];
-
 /*
  * Global array allocated for NR_CPUS at boot time
  */
@@ -94,13 +87,7 @@ struct sal_to_os_boot *sal_state_for_booting_cpu = &sal_boot_rendez_state[0];
 
 #define set_brendez_area(x) (sal_state_for_booting_cpu = &sal_boot_rendez_state[(x)]);
 
-#define get_idle_for_cpu(x)		(idle_thread_array[(x)])
-#define set_idle_for_cpu(x,p)	(idle_thread_array[(x)] = (p))
-
 #else
-
-#define get_idle_for_cpu(x)		(NULL)
-#define set_idle_for_cpu(x,p)
 #define set_brendez_area(x)
 #endif
 
@@ -480,54 +467,12 @@ struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
 	return NULL;
 }
 
-struct create_idle {
-	struct work_struct work;
-	struct task_struct *idle;
-	struct completion done;
-	int cpu;
-};
-
-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);
-}
-
 static int __cpuinit
-do_boot_cpu (int sapicid, int cpu)
+do_boot_cpu (int sapicid, int cpu, struct task_struct *idle)
 {
 	int timeout;
-	struct create_idle c_idle = {
-		.work = __WORK_INITIALIZER(c_idle.work, do_fork_idle),
-		.cpu	= cpu,
-		.done	= COMPLETION_INITIALIZER(c_idle.done),
-	};
-
-	/*
-	 * We can't use kernel_thread since we must avoid to
-	 * reschedule the child.
-	 */
- 	c_idle.idle = get_idle_for_cpu(cpu);
- 	if (c_idle.idle) {
-		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))
-		panic("failed fork for CPU %d", cpu);
-
-	set_idle_for_cpu(cpu, c_idle.idle);
-
-do_rest:
-	task_for_booting_cpu = c_idle.idle;
 
+	task_for_booting_cpu = idle;
 	Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 
 	set_brendez_area(cpu);
@@ -793,7 +738,7 @@ set_cpu_sibling_map(int cpu)
 }
 
 int __cpuinit
-__cpu_up (unsigned int cpu)
+__cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	int ret;
 	int sapicid;
@@ -811,7 +756,7 @@ __cpu_up (unsigned int cpu)
 
 	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 	/* Processor goes to start_secondary(), sets online flag */
-	ret = do_boot_cpu(sapicid, cpu);
+	ret = do_boot_cpu(sapicid, cpu, tidle);
 	if (ret < 0)
 		return ret;