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/Kconfig

@@ -145,6 +145,21 @@ config HAVE_DMA_ATTRS
 config USE_GENERIC_SMP_HELPERS
 	bool
 
+config GENERIC_SMP_IDLE_THREAD
+       bool
+
+# Select if arch init_task initializer is different to init/init_task.c
+config ARCH_INIT_TASK
+       bool
+
+# Select if arch has its private alloc_task_struct() function
+config ARCH_TASK_STRUCT_ALLOCATOR
+	bool
+
+# Select if arch has its private alloc_thread_info() function
+config ARCH_THREAD_INFO_ALLOCATOR
+	bool
+
 config HAVE_REGS_AND_STACK_ACCESS_API
 	bool
 	help

arch/alpha/Kconfig

@@ -15,6 +15,7 @@ config ALPHA
 	select GENERIC_IRQ_SHOW
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
+	select GENERIC_SMP_IDLE_THREAD
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,

arch/alpha/kernel/Makefile

@@ -6,7 +6,7 @@ extra-y		:= head.o vmlinux.lds
 asflags-y	:= $(KBUILD_CFLAGS)
 ccflags-y	:= -Wno-sign-compare
 
-obj-y    := entry.o traps.o process.o init_task.o osf_sys.o irq.o \
+obj-y    := entry.o traps.o process.o osf_sys.o irq.o \
 	    irq_alpha.o signal.o setup.o ptrace.o time.o \
 	    alpha_ksyms.o systbls.o err_common.o io.o
 

arch/alpha/kernel/smp.c

@@ -357,24 +357,10 @@ secondary_cpu_start(int cpuid, struct task_struct *idle)
  * Bring one cpu online.
  */
 static int __cpuinit
-smp_boot_one_cpu(int cpuid)
+smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 {
-	struct task_struct *idle;
 	unsigned long timeout;
 
-	/* Cook up an idler for this guy.  Note that the address we
-	   give to kernel_thread is irrelevant -- it's going to start
-	   where HWRPB.CPU_restart says to start.  But this gets all
-	   the other task-y sort of data structures set up like we
-	   wish.  We can't use kernel_thread since we must avoid
-	   rescheduling the child.  */
-	idle = fork_idle(cpuid);
-	if (IS_ERR(idle))
-		panic("failed fork for CPU %d", cpuid);
-
-	DBGS(("smp_boot_one_cpu: CPU %d state 0x%lx flags 0x%lx\n",
-	      cpuid, idle->state, idle->flags));
-
 	/* Signal the secondary to wait a moment.  */
 	smp_secondary_alive = -1;
 
@@ -487,9 +473,9 @@ smp_prepare_boot_cpu(void)
 }
 
 int __cpuinit
-__cpu_up(unsigned int cpu)
+__cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	smp_boot_one_cpu(cpu);
+	smp_boot_one_cpu(cpu, tidle);
 
 	return cpu_online(cpu) ? 0 : -ENOSYS;
 }

arch/arm/Kconfig

@@ -37,6 +37,7 @@ config ARM
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select GENERIC_PCI_IOMAP
 	select HAVE_BPF_JIT
+	select GENERIC_SMP_IDLE_THREAD
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and
@@ -154,9 +155,6 @@ config ARCH_HAS_CPUFREQ
 	  and that the relevant menu configurations are displayed for
 	  it.
 
-config ARCH_HAS_CPU_IDLE_WAIT
-       def_bool y
-
 config GENERIC_HWEIGHT
 	bool
 	default y

arch/arm/Makefile

@@ -117,7 +117,7 @@ KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_THUMB2) $(arch-y) $(tune-y) -include asm/
 CHECKFLAGS	+= -D__arm__
 
 #Default value
-head-y		:= arch/arm/kernel/head$(MMUEXT).o arch/arm/kernel/init_task.o
+head-y		:= arch/arm/kernel/head$(MMUEXT).o
 textofs-y	:= 0x00008000
 textofs-$(CONFIG_ARCH_CLPS711X) := 0x00028000
 # We don't want the htc bootloader to corrupt kernel during resume

arch/arm/include/asm/cpu.h

@@ -16,7 +16,6 @@
 struct cpuinfo_arm {
 	struct cpu	cpu;
 #ifdef CONFIG_SMP
-	struct task_struct *idle;
 	unsigned int	loops_per_jiffy;
 #endif
 };

arch/arm/include/asm/processor.h

@@ -88,8 +88,6 @@ unsigned long get_wchan(struct task_struct *p);
 #define cpu_relax()			barrier()
 #endif
 
-void cpu_idle_wait(void);
-
 /*
  * Create a new kernel thread
  */

arch/arm/kernel/Makefile

@@ -82,4 +82,4 @@ head-y			:= head$(MMUEXT).o
 obj-$(CONFIG_DEBUG_LL)	+= debug.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
-extra-y := $(head-y) init_task.o vmlinux.lds
+extra-y := $(head-y) vmlinux.lds

arch/arm/kernel/init_task.c

-/*
- *  linux/arch/arm/kernel/init_task.c
- */
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-#include <linux/uaccess.h>
-
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by making sure
- * the linker maps this in the .text segment right after head.S,
- * and making head.S ensure the proper alignment.
- *
- * The things we do for performance..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/arm/kernel/process.c

@@ -157,26 +157,6 @@ EXPORT_SYMBOL(pm_power_off);
 void (*arm_pm_restart)(char str, const char *cmd) = null_restart;
 EXPORT_SYMBOL_GPL(arm_pm_restart);
 
-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);
-
 /*
  * This is our default idle handler.
  */

arch/arm/kernel/smp.c

@@ -60,31 +60,10 @@ enum ipi_msg_type {
 
 static DECLARE_COMPLETION(cpu_running);
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
-	struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
-	struct task_struct *idle = ci->idle;
 	int ret;
 
-	/*
-	 * Spawn a new process manually, if not already done.
-	 * Grab a pointer to its task struct so we can mess with it
-	 */
-	if (!idle) {
-		idle = fork_idle(cpu);
-		if (IS_ERR(idle)) {
-			printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
-			return PTR_ERR(idle);
-		}
-		ci->idle = idle;
-	} else {
-		/*
-		 * Since this idle thread is being re-used, call
-		 * init_idle() to reinitialize the thread structure.
-		 */
-		init_idle(idle, cpu);
-	}
-
 	/*
 	 * We need to tell the secondary core where to find
 	 * its stack and the page tables.
@@ -318,9 +297,6 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 void __init smp_prepare_boot_cpu(void)
 {
-	unsigned int cpu = smp_processor_id();
-
-	per_cpu(cpu_data, cpu).idle = current;
 }
 
 void __init smp_prepare_cpus(unsigned int max_cpus)

arch/avr32/kernel/Makefile

@@ -8,7 +8,7 @@ obj-$(CONFIG_SUBARCH_AVR32B)	+= entry-avr32b.o
 obj-y				+= syscall_table.o syscall-stubs.o irq.o
 obj-y				+= setup.o traps.o ocd.o ptrace.o
 obj-y				+= signal.o sys_avr32.o process.o time.o
-obj-y				+= init_task.o switch_to.o cpu.o
+obj-y				+= switch_to.o cpu.o
 obj-$(CONFIG_MODULES)		+= module.o avr32_ksyms.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o

arch/avr32/kernel/init_task.c

-/*
- * Copyright (C) 2004-2006 Atmel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/module.h>
-#include <linux/fs.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure. Must be aligned on an 8192-byte boundary.
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/blackfin/Kconfig

@@ -37,6 +37,7 @@ config BLACKFIN
 	select GENERIC_IRQ_PROBE
 	select IRQ_PER_CPU if SMP
 	select HAVE_NMI_WATCHDOG if NMI_WATCHDOG
+	select GENERIC_SMP_IDLE_THREAD
 
 config GENERIC_CSUM
 	def_bool y

arch/blackfin/Makefile

@@ -109,8 +109,6 @@ KBUILD_AFLAGS += -mcpu=$(CPU_REV)
 CHECKFLAGS_SILICON = $(shell echo "" | $(CPP) $(KBUILD_CFLAGS) -dD - 2>/dev/null | awk '$$2 == "__SILICON_REVISION__" { print $$3 }')
 CHECKFLAGS += -D__SILICON_REVISION__=$(CHECKFLAGS_SILICON) -D__bfin__
 
-head-y   := arch/$(ARCH)/kernel/init_task.o
-
 core-y   += arch/$(ARCH)/kernel/ arch/$(ARCH)/mm/ arch/$(ARCH)/mach-common/
 
 # If we have a machine-specific directory, then include it in the build.

arch/blackfin/kernel/Makefile

@@ -2,7 +2,7 @@
 # arch/blackfin/kernel/Makefile
 #
 
-extra-y := init_task.o vmlinux.lds
+extra-y := vmlinux.lds
 
 obj-y := \
 	entry.o process.o bfin_ksyms.o ptrace.o setup.o signal.o \

arch/blackfin/kernel/init_task.c

-/*
- * Copyright 2004-2009 Analog Devices Inc.
- *
- * Licensed under the GPL-2 or later
- */
-
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-#include <linux/fs.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry.
- */
-union thread_union init_thread_union
-    __init_task_data = {
-INIT_THREAD_INFO(init_task)};

arch/blackfin/mach-common/smp.c

@@ -340,27 +340,10 @@ void smp_send_stop(void)
 	return;
 }
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
 	int ret;
-	struct blackfin_cpudata *ci = &per_cpu(cpu_data, cpu);
-	struct task_struct *idle = ci->idle;
 
-	if (idle) {
-		free_task(idle);
-		idle = NULL;
-	}
-
-	if (!idle) {
-		idle = fork_idle(cpu);
-		if (IS_ERR(idle)) {
-			printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
-			return PTR_ERR(idle);
-		}
-		ci->idle = idle;
-	} else {
-		init_idle(idle, cpu);
-	}
 	secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 
 	ret = platform_boot_secondary(cpu, idle);

arch/c6x/include/asm/thread_info.h

@@ -20,11 +20,11 @@
 #ifdef CONFIG_4KSTACKS
 #define THREAD_SIZE		4096
 #define THREAD_SHIFT		12
-#define THREAD_ORDER		0
+#define THREAD_SIZE_ORDER	0
 #else
 #define THREAD_SIZE		8192
 #define THREAD_SHIFT		13
-#define THREAD_ORDER		1
+#define THREAD_SIZE_ORDER	1
 #endif
 
 #define THREAD_START_SP		(THREAD_SIZE - 8)
@@ -80,19 +80,6 @@ struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-/* thread information allocation */
-#ifdef CONFIG_DEBUG_STACK_USAGE
-#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO)
-#else
-#define THREAD_FLAGS (GFP_KERNEL | __GFP_NOTRACK)
-#endif
-
-#define alloc_thread_info_node(tsk, node)	\
-	((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
-
-#define free_thread_info(ti)	free_pages((unsigned long) (ti), THREAD_ORDER)
 #define get_thread_info(ti)	get_task_struct((ti)->task)
 #define put_thread_info(ti)	put_task_struct((ti)->task)
 #endif /* __ASSEMBLY__ */

arch/c6x/kernel/process.c

@@ -26,22 +26,6 @@ void	(*c6x_halt)(void);
 
 extern asmlinkage void ret_from_fork(void);
 
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-
-/*
- * Initial thread structure.
- */
-union thread_union init_thread_union __init_task_data =	{
-	INIT_THREAD_INFO(init_task)
-};
-
-/*
- * Initial task structure.
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);
-
 /*
  * power off function, if any
  */

arch/cris/Kconfig

@@ -49,6 +49,7 @@ config CRIS
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IOMAP
+	select GENERIC_SMP_IDLE_THREAD if ETRAX_ARCH_V32
 
 config HZ
 	int

arch/cris/arch-v32/kernel/smp.c

@@ -108,17 +108,12 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 /* Bring one cpu online.*/
 static int __init
-smp_boot_one_cpu(int cpuid)
+smp_boot_one_cpu(int cpuid, struct task_struct idle)
 {
 	unsigned timeout;
-	struct task_struct *idle;
 	cpumask_t cpu_mask;
 
 	cpumask_clear(&cpu_mask);
-	idle = fork_idle(cpuid);
-	if (IS_ERR(idle))
-		panic("SMP: fork failed for CPU:%d", cpuid);
-
 	task_thread_info(idle)->cpu = cpuid;
 
 	/* Information to the CPU that is about to boot */
@@ -142,9 +137,6 @@ smp_boot_one_cpu(int cpuid)
 		barrier();
 	}
 
-	put_task_struct(idle);
-	idle = NULL;
-
 	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
 	return -1;
 }
@@ -207,9 +199,9 @@ int setup_profiling_timer(unsigned int multiplier)
  */
 unsigned long cache_decay_ticks = 1;
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	smp_boot_one_cpu(cpu);
+	smp_boot_one_cpu(cpu, tidle);
 	return cpu_online(cpu) ? 0 : -ENOSYS;
 }
 

arch/cris/include/asm/processor.h

@@ -25,13 +25,12 @@ struct task_struct;
  */
 #define TASK_UNMAPPED_BASE      (PAGE_ALIGN(TASK_SIZE / 3))
 
-/* THREAD_SIZE is the size of the task_struct/kernel_stack combo.
+/* THREAD_SIZE is the size of the thread_info/kernel_stack combo.
  * normally, the stack is found by doing something like p + THREAD_SIZE
  * in CRIS, a page is 8192 bytes, which seems like a sane size
  */
-
 #define THREAD_SIZE       PAGE_SIZE
-#define KERNEL_STACK_SIZE PAGE_SIZE
+#define THREAD_SIZE_ORDER (0)
 
 /*
  * At user->kernel entry, the pt_regs struct is stacked on the top of the kernel-stack.

arch/cris/include/asm/thread_info.h

@@ -65,12 +65,6 @@ struct thread_info {
 
 #define init_thread_info	(init_thread_union.thread_info)
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-/* thread information allocation */
-#define alloc_thread_info_node(tsk, node)	\
-	((struct thread_info *) __get_free_pages(GFP_KERNEL, 1))
-#define free_thread_info(ti) free_pages((unsigned long) (ti), 1)
-
 #endif /* !__ASSEMBLY__ */
 
 /*

arch/cris/kernel/process.c

@@ -28,34 +28,6 @@
 
 //#define DEBUG
 
-/*
- * Initial task structure. Make this a per-architecture thing,
- * because different architectures tend to have different
- * alignment requirements and potentially different initial
- * setup.
- */
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);
-
 /*
  * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
  * there would ever be a halt sequence (for power save when idle) with

arch/frv/Makefile

@@ -81,7 +81,7 @@ ifdef CONFIG_DEBUG_INFO
 KBUILD_AFLAGS	+= -Wa,--gdwarf2
 endif
 
-head-y		:= arch/frv/kernel/head.o arch/frv/kernel/init_task.o
+head-y		:= arch/frv/kernel/head.o
 
 core-y		+= arch/frv/kernel/ arch/frv/mm/
 libs-y		+= arch/frv/lib/

arch/frv/include/asm/thread_info.h

@@ -21,8 +21,6 @@
 
 #define THREAD_SIZE		8192
 
-#define __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
-
 /*
  * low level task data that entry.S needs immediate access to
  * - this struct should fit entirely inside of one cache line
@@ -82,19 +80,6 @@ register struct thread_info *__current_thread_info asm("gr15");
 
 #define current_thread_info() ({ __current_thread_info; })
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-/* thread information allocation */
-#ifdef CONFIG_DEBUG_STACK_USAGE
-#define alloc_thread_info_node(tsk, node)			\
-		kzalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#else
-#define alloc_thread_info_node(tsk, node)			\
-		kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#endif
-
-#define free_thread_info(info)	kfree(info)
-
 #endif /* __ASSEMBLY__ */
 
 /*

arch/frv/kernel/Makefile

@@ -5,7 +5,7 @@
 heads-y				:= head-uc-fr401.o head-uc-fr451.o head-uc-fr555.o
 heads-$(CONFIG_MMU)		:= head-mmu-fr451.o
 
-extra-y:= head.o init_task.o vmlinux.lds
+extra-y:= head.o vmlinux.lds
 
 obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o kernel_thread.o \
 	 kernel_execve.o process.o traps.o ptrace.o signal.o dma.o \

arch/frv/kernel/init_task.c

-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/frv/kernel/process.c

@@ -43,21 +43,6 @@ asmlinkage void ret_from_fork(void);
 void (*pm_power_off)(void);
 EXPORT_SYMBOL(pm_power_off);
 
-struct task_struct *alloc_task_struct_node(int node)
-{
-	struct task_struct *p = kmalloc_node(THREAD_SIZE, GFP_KERNEL, node);
-
-	if (p)
-		atomic_set((atomic_t *)(p+1), 1);
-	return p;
-}
-
-void free_task_struct(struct task_struct *p)
-{
-	if (atomic_dec_and_test((atomic_t *)(p+1)))
-		kfree(p);
-}
-
 static void core_sleep_idle(void)
 {
 #ifdef LED_DEBUG_SLEEP

arch/h8300/kernel/Makefile

@@ -6,7 +6,7 @@ extra-y := vmlinux.lds
 
 obj-y := process.o traps.o ptrace.o irq.o \
 	 sys_h8300.o time.o signal.o \
-         setup.o gpio.o init_task.o syscalls.o \
+         setup.o gpio.o syscalls.o \
 	 entry.o timer/
 
 obj-$(CONFIG_MODULES) += module.o h8300_ksyms.o 

arch/h8300/kernel/init_task.c

-/*
- *  linux/arch/h8300/kernel/init_task.c
- */
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-__asm__(".align 4");
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-

arch/hexagon/Kconfig

@@ -27,6 +27,7 @@ config HEXAGON
 	select HAVE_ARCH_TRACEHOOK
 	select NO_IOPORT
 	select GENERIC_IOMAP
+	select GENERIC_SMP_IDLE_THREAD
 	# mostly generic routines, with some accelerated ones
 	---help---
 	  Qualcomm Hexagon is a processor architecture designed for high

arch/hexagon/Makefile

@@ -45,8 +45,7 @@ KBUILD_AFLAGS += -DTHREADINFO_REG=$(TIR_NAME)
 LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 libs-y += $(LIBGCC)
 
-head-y := arch/hexagon/kernel/head.o \
-	arch/hexagon/kernel/init_task.o
+head-y := arch/hexagon/kernel/head.o
 
 core-y += arch/hexagon/kernel/ \
 	arch/hexagon/mm/ \

arch/hexagon/include/asm/thread_info.h

@@ -31,15 +31,7 @@
 
 #define THREAD_SHIFT		12
 #define THREAD_SIZE		(1<<THREAD_SHIFT)
-
-#if THREAD_SHIFT >= PAGE_SHIFT
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
-#else  /*  don't use standard allocator  */
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-extern struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node);
-extern void free_thread_info(struct thread_info *ti);
-#endif
-
 
 #ifndef __ASSEMBLY__
 

arch/hexagon/kernel/Makefile

-extra-y := head.o vmlinux.lds init_task.o
+extra-y := head.o vmlinux.lds
 
 obj-$(CONFIG_SMP) += smp.o topology.o
 

arch/hexagon/kernel/init_task.c

-/*
- * Init task definition
- *
- * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA.
- */
-
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-#include <asm/thread_info.h>
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by making sure
- * the linker maps this in the .text segment right after head.S,
- * and making head.S ensure the proper alignment.
- */
-union thread_union init_thread_union
-	__attribute__((__section__(".data.init_task"),
-		__aligned__(THREAD_SIZE))) = {
-			INIT_THREAD_INFO(init_task)
-		};
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);

arch/hexagon/kernel/process.c

@@ -233,43 +233,6 @@ unsigned long get_wchan(struct task_struct *p)
 	return 0;
 }
 
-/*
- * Borrowed from PowerPC -- basically allow smaller kernel stacks if we
- * go crazy with the page sizes.
- */
-#if THREAD_SHIFT < PAGE_SHIFT
-
-static struct kmem_cache *thread_info_cache;
-
-struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node)
-{
-	struct thread_info *ti;
-
-	ti = kmem_cache_alloc_node(thread_info_cache, GFP_KERNEL, node);
-	if (unlikely(ti == NULL))
-		return NULL;
-#ifdef CONFIG_DEBUG_STACK_USAGE
-	memset(ti, 0, THREAD_SIZE);
-#endif
-	return ti;
-}
-
-void free_thread_info(struct thread_info *ti)
-{
-	kmem_cache_free(thread_info_cache, ti);
-}
-
-/*  Weak symbol; called by init/main.c  */
-
-void thread_info_cache_init(void)
-{
-	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
-					      THREAD_SIZE, 0, NULL);
-	BUG_ON(thread_info_cache == NULL);
-}
-
-#endif /* THREAD_SHIFT < PAGE_SHIFT */
-
 /*
  * Required placeholder.
  */

arch/hexagon/kernel/smp.c

@@ -196,18 +196,11 @@ void __cpuinit start_secondary(void)
  * maintains control until "cpu_online(cpu)" is set.
  */
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
 {
-	struct task_struct *idle;
-	struct thread_info *thread;
+	struct thread_info *thread = (struct thread_info *)idle->stack;
 	void *stack_start;
 
-	/*  Create new init task for the CPU  */
-	idle = fork_idle(cpu);
-	if (IS_ERR(idle))
-		panic(KERN_ERR "fork_idle failed\n");
-
-	thread = (struct thread_info *)idle->stack;
 	thread->cpu = cpu;
 
 	/*  Boot to the head.  */

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;
 

arch/m32r/Makefile

@@ -31,7 +31,7 @@ KBUILD_AFLAGS += $(aflags-y)
 
 CHECKFLAGS	+= -D__m32r__ -D__BIG_ENDIAN__=1
 
-head-y	:= arch/m32r/kernel/head.o arch/m32r/kernel/init_task.o
+head-y	:= arch/m32r/kernel/head.o
 
 LIBGCC	:= $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
 

arch/m32r/include/asm/thread_info.h

@@ -55,8 +55,8 @@ struct thread_info {
 
 #define PREEMPT_ACTIVE		0x10000000
 
-#define THREAD_SIZE (PAGE_SIZE << 1)
-
+#define THREAD_SIZE		(PAGE_SIZE << 1)
+#define THREAD_SIZE_ORDER	1
 /*
  * macros/functions for gaining access to the thread information structure
  */
@@ -92,19 +92,6 @@ static inline struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-/* thread information allocation */
-#ifdef CONFIG_DEBUG_STACK_USAGE
-#define alloc_thread_info_node(tsk, node)			\
-		kzalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#else
-#define alloc_thread_info_node(tsk, node)			\
-		kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#endif
-
-#define free_thread_info(info) kfree(info)
-
 #define TI_FLAG_FAULT_CODE_SHIFT	28
 
 static inline void set_thread_fault_code(unsigned int val)

arch/m32r/kernel/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the Linux/M32R kernel.
 #
 
-extra-y	:= head.o init_task.o vmlinux.lds
+extra-y	:= head.o vmlinux.lds
 
 obj-y	:= process.o entry.o traps.o align.o irq.o setup.o time.o \
 	m32r_ksyms.o sys_m32r.o signal.o ptrace.o

arch/m32r/kernel/init_task.c

-/* orig : i386 init_task.c */
-
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);
-

arch/m32r/kernel/smpboot.c

@@ -109,12 +109,8 @@ static unsigned int calibration_result;
 /* Function Prototypes                                                       */
 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
 
-void smp_prepare_boot_cpu(void);
-void smp_prepare_cpus(unsigned int);
 static void init_ipi_lock(void);
 static void do_boot_cpu(int);
-int __cpu_up(unsigned int);
-void smp_cpus_done(unsigned int);
 
 int start_secondary(void *);
 static void smp_callin(void);
@@ -347,7 +343,7 @@ static void __init do_boot_cpu(int phys_id)
 	}
 }
 
-int __cpuinit __cpu_up(unsigned int cpu_id)
+int __cpuinit __cpu_up(unsigned int cpu_id, struct task_struct *tidle)
 {
 	int timeout;
 

arch/m68k/kernel/Makefile

@@ -13,7 +13,7 @@ extra-$(CONFIG_SUN3X)	:= head.o
 extra-$(CONFIG_SUN3)	:= sun3-head.o
 extra-y			+= vmlinux.lds
 
-obj-y	:= entry.o init_task.o irq.o m68k_ksyms.o module.o process.o ptrace.o
+obj-y	:= entry.o irq.o m68k_ksyms.o module.o process.o ptrace.o
 obj-y	+= setup.o signal.o sys_m68k.o syscalltable.o time.o traps.o
 
 obj-$(CONFIG_MMU_MOTOROLA) += ints.o vectors.o

arch/m68k/kernel/init_task.c

-/*
- *  linux/arch/m68knommu/kernel/init_task.c
- */
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD size aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-

arch/microblaze/kernel/Makefile

@@ -16,7 +16,7 @@ endif
 extra-y := head.o vmlinux.lds
 
 obj-y += dma.o exceptions.o \
-	hw_exception_handler.o init_task.o intc.o irq.o \
+	hw_exception_handler.o intc.o irq.o \
 	process.o prom.o prom_parse.o ptrace.o \
 	reset.o setup.o signal.o sys_microblaze.o timer.o traps.o unwind.o
 

arch/microblaze/kernel/init_task.c

-/*
- * Copyright (C) 2009 Michal Simek <monstr@monstr.eu>
- * Copyright (C) 2009 PetaLogix
- * Copyright (C) 2006 Atmark Techno, Inc.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);

arch/mips/Kconfig

@@ -29,6 +29,7 @@ config MIPS
 	select HAVE_MEMBLOCK
 	select HAVE_MEMBLOCK_NODE_MAP
 	select ARCH_DISCARD_MEMBLOCK
+	select GENERIC_SMP_IDLE_THREAD
 
 menu "Machine selection"
 

arch/mips/Makefile

@@ -235,7 +235,7 @@ endif
 
 OBJCOPYFLAGS		+= --remove-section=.reginfo
 
-head-y := arch/mips/kernel/head.o arch/mips/kernel/init_task.o
+head-y := arch/mips/kernel/head.o
 
 libs-y			+= arch/mips/lib/
 

arch/mips/include/asm/thread_info.h

@@ -85,18 +85,6 @@ register struct thread_info *__current_thread_info __asm__("$28");
 
 #define STACK_WARN	(THREAD_SIZE / 8)
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-#ifdef CONFIG_DEBUG_STACK_USAGE
-#define alloc_thread_info_node(tsk, node) \
-		kzalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#else
-#define alloc_thread_info_node(tsk, node) \
-		kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#endif
-
-#define free_thread_info(info) kfree(info)
-
 #endif /* !__ASSEMBLY__ */
 
 #define PREEMPT_ACTIVE		0x10000000

arch/mips/kernel/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the Linux/MIPS kernel.
 #
 
-extra-y		:= head.o init_task.o vmlinux.lds
+extra-y		:= head.o vmlinux.lds
 
 obj-y		+= cpu-probe.o branch.o entry.o genex.o irq.o process.o \
 		   ptrace.o reset.o setup.o signal.o syscall.o \

arch/mips/kernel/init_task.c

-#include <linux/mm.h>
-#include <linux/export.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-
-#include <asm/thread_info.h>
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by making sure
- * the linker maps this in the .text segment right after head.S,
- * and making head.S ensure the proper alignment.
- *
- * The things we do for performance..
- */
-union thread_union init_thread_union __init_task_data
-	__attribute__((__aligned__(THREAD_SIZE))) =
-		{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/mips/kernel/smp.c

@@ -186,61 +186,9 @@ void __devinit smp_prepare_boot_cpu(void)
 	cpu_set(0, cpu_callin_map);
 }
 
-/*
- * Called once for each "cpu_possible(cpu)".  Needs to spin up the cpu
- * and keep control until "cpu_online(cpu)" is set.  Note: cpu is
- * physical, not logical.
- */
-static struct task_struct *cpu_idle_thread[NR_CPUS];
-
-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);
-}
-
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	struct task_struct *idle;
-
-	/*
-	 * Processor goes to start_secondary(), sets online flag
-	 * The following code is purely to make sure
-	 * Linux can schedule processes on this slave.
-	 */
-	if (!cpu_idle_thread[cpu]) {
-		/*
-		 * Schedule work item to avoid forking user task
-		 * Ported from arch/x86/kernel/smpboot.c
-		 */
-		struct create_idle c_idle = {
-			.cpu    = cpu,
-			.done   = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
-		};
-
-		INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
-		schedule_work(&c_idle.work);
-		wait_for_completion(&c_idle.done);
-		idle = cpu_idle_thread[cpu] = c_idle.idle;
-
-		if (IS_ERR(idle))
-			panic(KERN_ERR "Fork failed for CPU %d", cpu);
-	} else {
-		idle = cpu_idle_thread[cpu];
-		init_idle(idle, cpu);
-	}
-
-	mp_ops->boot_secondary(cpu, idle);
+	mp_ops->boot_secondary(cpu, tidle);
 
 	/*
 	 * Trust is futile.  We should really have timeouts ...

arch/mn10300/Makefile

@@ -51,7 +51,7 @@ UNIT		:= asb2364
 endif
 
 
-head-y		:= arch/mn10300/kernel/head.o arch/mn10300/kernel/init_task.o
+head-y		:= arch/mn10300/kernel/head.o
 
 core-y		+= arch/mn10300/kernel/ arch/mn10300/mm/
 

arch/mn10300/include/asm/thread_info.h

@@ -20,8 +20,10 @@
 
 #ifdef CONFIG_4KSTACKS
 #define THREAD_SIZE		(4096)
+#define THREAD_SIZE_ORDER	(0)
 #else
 #define THREAD_SIZE		(8192)
+#define THREAD_SIZE_ORDER	(1)
 #endif
 
 #define STACK_WARN		(THREAD_SIZE / 8)
@@ -120,21 +122,8 @@ static inline unsigned long current_stack_pointer(void)
 	return sp;
 }
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-/* thread information allocation */
-#ifdef CONFIG_DEBUG_STACK_USAGE
-#define alloc_thread_info_node(tsk, node)			\
-		kzalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#else
-#define alloc_thread_info_node(tsk, node)			\
-		kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#endif
-
 #ifndef CONFIG_KGDB
-#define free_thread_info(ti)	kfree((ti))
-#else
-extern void free_thread_info(struct thread_info *);
+void arch_release_thread_info(struct thread_info *ti)
 #endif
 #define get_thread_info(ti)	get_task_struct((ti)->task)
 #define put_thread_info(ti)	put_task_struct((ti)->task)

arch/mn10300/kernel/Makefile

 #
 # Makefile for the MN10300-specific core kernel code
 #
-extra-y := head.o init_task.o vmlinux.lds
+extra-y := head.o vmlinux.lds
 
 fpu-obj-y := fpu-nofpu.o fpu-nofpu-low.o
 fpu-obj-$(CONFIG_FPU) := fpu.o fpu-low.o

arch/mn10300/kernel/init_task.c

-/* MN10300 Initial task definitions
- *
- * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);

arch/mn10300/kernel/kgdb.c

@@ -397,7 +397,7 @@ static bool kgdb_arch_undo_singlestep(struct pt_regs *regs)
  * single-step state is cleared.  At this point the breakpoints should have
  * been removed by __switch_to().
  */
-void free_thread_info(struct thread_info *ti)
+void arch_release_thread_info(struct thread_info *ti)
 {
 	if (kgdb_sstep_thread == ti) {
 		kgdb_sstep_thread = NULL;
@@ -407,7 +407,6 @@ void free_thread_info(struct thread_info *ti)
 		 * so force immediate reentry */
 		kgdb_breakpoint();
 	}
-	kfree(ti);
 }
 
 /*

arch/mn10300/kernel/smp.c

@@ -924,7 +924,7 @@ void initialize_secondary(void)
  * __cpu_up - Set smp_commenced_mask for the nominated CPU
  * @cpu: The target CPU.
  */
-int __devinit __cpu_up(unsigned int cpu)
+int __devinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	int timeout;
 

arch/openrisc/Makefile

@@ -38,7 +38,7 @@ else
 	KBUILD_CFLAGS += $(call cc-option,-msoft-div)
 endif
 
-head-y 		:= arch/openrisc/kernel/head.o arch/openrisc/kernel/init_task.o
+head-y 		:= arch/openrisc/kernel/head.o
 
 core-y		+= arch/openrisc/lib/ \
 		   arch/openrisc/kernel/ \

arch/openrisc/kernel/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-extra-y	:= head.o vmlinux.lds init_task.o
+extra-y	:= head.o vmlinux.lds
 
 obj-y	:= setup.o idle.o or32_ksyms.o process.o dma.o \
 	   traps.o time.o irq.o entry.o ptrace.o signal.o sys_or32.o \

arch/openrisc/kernel/init_task.c

-/*
- * OpenRISC init_task.c
- *
- * Linux architectural port borrowing liberally from similar works of
- * others.  All original copyrights apply as per the original source
- * declaration.
- *
- * Modifications for the OpenRISC architecture:
- * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
- * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
- *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- */
-
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-#include <linux/export.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data = {
-	INIT_THREAD_INFO(init_task)
-};
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);

arch/parisc/Kconfig

@@ -17,6 +17,7 @@ config PARISC
 	select GENERIC_PCI_IOMAP
 	select IRQ_PER_CPU
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
+	select GENERIC_SMP_IDLE_THREAD
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used

arch/parisc/Makefile

@@ -75,7 +75,7 @@ head-y			:= arch/parisc/kernel/head.o
 
 KBUILD_CFLAGS	+= $(cflags-y)
 
-kernel-y			:= mm/ kernel/ math-emu/ kernel/init_task.o
+kernel-y			:= mm/ kernel/ math-emu/
 kernel-$(CONFIG_HPUX)		+= hpux/
 
 core-y	+= $(addprefix arch/parisc/, $(kernel-y))

arch/parisc/kernel/Makefile

@@ -2,7 +2,7 @@
 # Makefile for arch/parisc/kernel
 #
 
-extra-y			:= init_task.o head.o vmlinux.lds
+extra-y			:= head.o vmlinux.lds
 
 obj-y	     	:= cache.o pacache.o setup.o traps.o time.o irq.o \
 		   pa7300lc.o syscall.o entry.o sys_parisc.o firmware.o \

arch/parisc/kernel/init_task.c

-/* 
- *    Static declaration of "init" task data structure.
- *
- *    Copyright (C) 2000 Paul Bame <bame at parisc-linux.org>
- *    Copyright (C) 2000-2001 John Marvin <jsm at parisc-linux.org>
- *    Copyright (C) 2001 Helge Deller <deller @ parisc-linux.org>
- *    Copyright (C) 2002 Matthew Wilcox <willy with parisc-linux.org>
- *
- *
- *    This program is free software; you can redistribute it and/or modify
- *    it under the terms of the GNU General Public License as published by
- *    the Free Software Foundation; either version 2 of the License, or
- *    (at your option) any later version.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU General Public License for more details.
- *
- *    You should have received a copy of the GNU General Public License
- *    along with this program; if not, write to the Free Software
- *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- */
-
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-#include <asm/pgalloc.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial task structure.
- *
- * We need to make sure that this is 16384-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data
-	__attribute__((aligned(128))) =
-		{ INIT_THREAD_INFO(init_task) };
-
-#if PT_NLEVELS == 3
-/* NOTE: This layout exactly conforms to the hybrid L2/L3 page table layout
- * with the first pmd adjacent to the pgd and below it. gcc doesn't actually
- * guarantee that global objects will be laid out in memory in the same order 
- * as the order of declaration, so put these in different sections and use
- * the linker script to order them. */
-pmd_t pmd0[PTRS_PER_PMD] __attribute__ ((__section__ (".data..vm0.pmd"), aligned(PAGE_SIZE)));
-#endif
-
-pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__ ((__section__ (".data..vm0.pgd"), aligned(PAGE_SIZE)));
-pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __attribute__ ((__section__ (".data..vm0.pte"), aligned(PAGE_SIZE)));
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-EXPORT_SYMBOL(init_task);
-
-__asm__(".data");
-struct task_struct init_task = INIT_TASK(init_task);

arch/parisc/kernel/smp.c

@@ -340,26 +340,11 @@ void __init smp_callin(void)
 /*
  * Bring one cpu online.
  */
-int __cpuinit smp_boot_one_cpu(int cpuid)
+int __cpuinit smp_boot_one_cpu(int cpuid, struct task_struct *idle)
 {
 	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
-	struct task_struct *idle;
 	long timeout;
 
-	/* 
-	 * Create an idle task for this CPU.  Note the address wed* give 
-	 * to kernel_thread is irrelevant -- it's going to start
-	 * where OS_BOOT_RENDEVZ vector in SAL says to start.  But
-	 * this gets all the other task-y sort of data structures set
-	 * up like we wish.   We need to pull the just created idle task 
-	 * off the run queue and stuff it into the init_tasks[] array.  
-	 * Sheesh . . .
-	 */
-
-	idle = fork_idle(cpuid);
-	if (IS_ERR(idle))
-		panic("SMP: fork failed for CPU:%d", cpuid);
-
 	task_thread_info(idle)->cpu = cpuid;
 
 	/* Let _start know what logical CPU we're booting
@@ -403,10 +388,6 @@ int __cpuinit smp_boot_one_cpu(int cpuid)
 		udelay(100);
 		barrier();
 	}
-
-	put_task_struct(idle);
-	idle = NULL;
-
 	printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
 	return -1;
 
@@ -455,10 +436,10 @@ void smp_cpus_done(unsigned int cpu_max)
 }
 
 
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	if (cpu != 0 && cpu < parisc_max_cpus)
-		smp_boot_one_cpu(cpu);
+		smp_boot_one_cpu(cpu, tidle);
 
 	return cpu_online(cpu) ? 0 : -ENOSYS;
 }

arch/parisc/mm/init.c

@@ -33,6 +33,18 @@
 
 extern int  data_start;
 
+#if PT_NLEVELS == 3
+/* NOTE: This layout exactly conforms to the hybrid L2/L3 page table layout
+ * with the first pmd adjacent to the pgd and below it. gcc doesn't actually
+ * guarantee that global objects will be laid out in memory in the same order
+ * as the order of declaration, so put these in different sections and use
+ * the linker script to order them. */
+pmd_t pmd0[PTRS_PER_PMD] __attribute__ ((__section__ (".data..vm0.pmd"), aligned(PAGE_SIZE)));
+#endif
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__ ((__section__ (".data..vm0.pgd"), aligned(PAGE_SIZE)));
+pte_t pg0[PT_INITIAL * PTRS_PER_PTE] __attribute__ ((__section__ (".data..vm0.pte"), aligned(PAGE_SIZE)));
+
 #ifdef CONFIG_DISCONTIGMEM
 struct node_map_data node_data[MAX_NUMNODES] __read_mostly;
 unsigned char pfnnid_map[PFNNID_MAP_MAX] __read_mostly;

arch/powerpc/Kconfig

@@ -87,10 +87,6 @@ config ARCH_HAS_ILOG2_U64
 	bool
 	default y if 64BIT
 
-config ARCH_HAS_CPU_IDLE_WAIT
-	bool
-	default y
-
 config GENERIC_HWEIGHT
 	bool
 	default y
@@ -144,6 +140,7 @@ config PPC
 	select HAVE_BPF_JIT if PPC64
 	select HAVE_ARCH_JUMP_LABEL
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
+	select GENERIC_SMP_IDLE_THREAD
 
 config EARLY_PRINTK
 	bool

arch/powerpc/include/asm/processor.h

@@ -386,7 +386,6 @@ extern unsigned long cpuidle_disable;
 enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF};
 
 extern int powersave_nap;	/* set if nap mode can be used in idle loop */
-void cpu_idle_wait(void);
 
 #ifdef CONFIG_PSERIES_IDLE
 extern void update_smt_snooze_delay(int snooze);

arch/powerpc/include/asm/thread_info.h

@@ -62,21 +62,8 @@ struct thread_info {
 #define init_thread_info	(init_thread_union.thread_info)
 #define init_stack		(init_thread_union.stack)
 
-/* thread information allocation */
-
-#if THREAD_SHIFT >= PAGE_SHIFT
-
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
-#else /* THREAD_SHIFT < PAGE_SHIFT */
-
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
-extern struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node);
-extern void free_thread_info(struct thread_info *ti);
-
-#endif /* THREAD_SHIFT < PAGE_SHIFT */
-
 /* how to get the thread information struct from C */
 static inline struct thread_info *current_thread_info(void)
 {

arch/powerpc/kernel/Makefile

@@ -28,7 +28,7 @@ endif
 
 obj-y				:= cputable.o ptrace.o syscalls.o \
 				   irq.o align.o signal_32.o pmc.o vdso.o \
-				   init_task.o process.o systbl.o idle.o \
+				   process.o systbl.o idle.o \
 				   signal.o sysfs.o cacheinfo.o time.o \
 				   prom.o traps.o setup-common.o \
 				   udbg.o misc.o io.o dma.o \

arch/powerpc/kernel/idle.c

@@ -113,29 +113,6 @@ void cpu_idle(void)
 	}
 }
 
-
-/*
- * cpu_idle_wait - Used to ensure that all the CPUs come out of the old
- * idle loop and start using the new idle loop.
- * Required while changing idle handler on SMP systems.
- * Caller must have changed idle handler to the new value before the call.
- * This window may be larger on shared systems.
- */
-void cpu_idle_wait(void)
-{
-	int cpu;
-	smp_mb();
-
-	/* kick all the CPUs so that they exit out of old idle routine */
-	get_online_cpus();
-	for_each_online_cpu(cpu) {
-		if (cpu != smp_processor_id())
-			smp_send_reschedule(cpu);
-	}
-	put_online_cpus();
-}
-EXPORT_SYMBOL_GPL(cpu_idle_wait);
-
 int powersave_nap;
 
 #ifdef CONFIG_SYSCTL

arch/powerpc/kernel/init_task.c

-#include <linux/mm.h>
-#include <linux/export.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/init_task.h>
-#include <linux/fs.h>
-#include <linux/mqueue.h>
-#include <asm/uaccess.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 16384-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/powerpc/kernel/process.c

@@ -1252,37 +1252,6 @@ void __ppc64_runlatch_off(void)
 }
 #endif /* CONFIG_PPC64 */
 
-#if THREAD_SHIFT < PAGE_SHIFT
-
-static struct kmem_cache *thread_info_cache;
-
-struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node)
-{
-	struct thread_info *ti;
-
-	ti = kmem_cache_alloc_node(thread_info_cache, GFP_KERNEL, node);
-	if (unlikely(ti == NULL))
-		return NULL;
-#ifdef CONFIG_DEBUG_STACK_USAGE
-	memset(ti, 0, THREAD_SIZE);
-#endif
-	return ti;
-}
-
-void free_thread_info(struct thread_info *ti)
-{
-	kmem_cache_free(thread_info_cache, ti);
-}
-
-void thread_info_cache_init(void)
-{
-	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
-					      THREAD_SIZE, 0, NULL);
-	BUG_ON(thread_info_cache == NULL);
-}
-
-#endif /* THREAD_SHIFT < PAGE_SHIFT */
-
 unsigned long arch_align_stack(unsigned long sp)
 {
 	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)

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

arch/s390/Kconfig

@@ -122,6 +122,7 @@ config S390
 	select ARCH_INLINE_WRITE_UNLOCK_BH
 	select ARCH_INLINE_WRITE_UNLOCK_IRQ
 	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
+	select GENERIC_SMP_IDLE_THREAD
 
 config SCHED_OMIT_FRAME_POINTER
 	def_bool y

arch/s390/Makefile

@@ -91,7 +91,6 @@ OBJCOPYFLAGS	:= -O binary
 
 head-y		:= arch/s390/kernel/head.o
 head-y		+= arch/s390/kernel/$(if $(CONFIG_64BIT),head64.o,head31.o)
-head-y		+= arch/s390/kernel/init_task.o
 
 # See arch/s390/Kbuild for content of core part of the kernel
 core-y		+= arch/s390/

arch/s390/include/asm/smp.h

@@ -16,7 +16,7 @@
 extern struct mutex smp_cpu_state_mutex;
 extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 
-extern int __cpu_up(unsigned int cpu);
+extern int __cpu_up(unsigned int cpu, struct task_struct *tidle);
 
 extern void arch_send_call_function_single_ipi(int cpu);
 extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);

arch/s390/kernel/Makefile

@@ -28,7 +28,7 @@ obj-y	:=  bitmap.o traps.o time.o process.o base.o early.o setup.o vtime.o \
 obj-y	+= $(if $(CONFIG_64BIT),entry64.o,entry.o)
 obj-y	+= $(if $(CONFIG_64BIT),reipl64.o,reipl.o)
 
-extra-y				+= head.o init_task.o vmlinux.lds
+extra-y				+= head.o vmlinux.lds
 extra-y				+= $(if $(CONFIG_64BIT),head64.o,head31.o)
 
 obj-$(CONFIG_MODULES)		+= s390_ksyms.o module.o

arch/s390/kernel/init_task.c

-/*
- *  arch/s390/kernel/init_task.c
- *
- *  S390 version
- *
- *  Derived from "arch/i386/kernel/init_task.c"
- */
-
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/s390/kernel/smp.c

@@ -85,7 +85,6 @@ enum {
 
 struct pcpu {
 	struct cpu cpu;
-	struct task_struct *idle;	/* idle process for the cpu */
 	struct _lowcore *lowcore;	/* lowcore page(s) for the cpu */
 	unsigned long async_stack;	/* async stack for the cpu */
 	unsigned long panic_stack;	/* panic stack for the cpu */
@@ -725,26 +724,9 @@ static void __cpuinit smp_start_secondary(void *cpuvoid)
 	cpu_idle();
 }
 
-struct create_idle {
-	struct work_struct work;
-	struct task_struct *idle;
-	struct completion done;
-	int cpu;
-};
-
-static void __cpuinit smp_fork_idle(struct work_struct *work)
-{
-	struct create_idle *c_idle;
-
-	c_idle = container_of(work, struct create_idle, work);
-	c_idle->idle = fork_idle(c_idle->cpu);
-	complete(&c_idle->done);
-}
-
 /* Upping and downing of CPUs */
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
-	struct create_idle c_idle;
 	struct pcpu *pcpu;
 	int rc;
 
@@ -754,22 +736,12 @@ int __cpuinit __cpu_up(unsigned int cpu)
 	if (pcpu_sigp_retry(pcpu, sigp_initial_cpu_reset, 0) !=
 	    sigp_order_code_accepted)
 		return -EIO;
-	if (!pcpu->idle) {
-		c_idle.done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done);
-		INIT_WORK_ONSTACK(&c_idle.work, smp_fork_idle);
-		c_idle.cpu = cpu;
-		schedule_work(&c_idle.work);
-		wait_for_completion(&c_idle.done);
-		if (IS_ERR(c_idle.idle))
-			return PTR_ERR(c_idle.idle);
-		pcpu->idle = c_idle.idle;
-	}
-	init_idle(pcpu->idle, cpu);
+
 	rc = pcpu_alloc_lowcore(pcpu, cpu);
 	if (rc)
 		return rc;
 	pcpu_prepare_secondary(pcpu, cpu);
-	pcpu_attach_task(pcpu, pcpu->idle);
+	pcpu_attach_task(pcpu, tidle);
 	pcpu_start_fn(pcpu, smp_start_secondary, NULL);
 	while (!cpu_online(cpu))
 		cpu_relax();
@@ -856,7 +828,6 @@ void __init smp_prepare_boot_cpu(void)
 	struct pcpu *pcpu = pcpu_devices;
 
 	boot_cpu_address = stap();
-	pcpu->idle = current;
 	pcpu->state = CPU_STATE_CONFIGURED;
 	pcpu->address = boot_cpu_address;
 	pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();

arch/score/include/asm/thread_info.h

@@ -11,10 +11,9 @@
 #include <linux/const.h>
 
 /* thread information allocation */
-#define THREAD_SIZE_ORDER 	(1)
-#define THREAD_SIZE 		(PAGE_SIZE << THREAD_SIZE_ORDER)
-#define THREAD_MASK 		(THREAD_SIZE - _AC(1,UL))
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
+#define THREAD_SIZE_ORDER	(1)
+#define THREAD_SIZE		(PAGE_SIZE << THREAD_SIZE_ORDER)
+#define THREAD_MASK		(THREAD_SIZE - _AC(1,UL))
 
 #ifndef __ASSEMBLY__
 
@@ -71,9 +70,6 @@ struct thread_info {
 register struct thread_info *__current_thread_info __asm__("r28");
 #define current_thread_info()	__current_thread_info
 
-#define alloc_thread_info_node(tsk, node) kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
-#define free_thread_info(info) kfree(info)
-
 #endif /* !__ASSEMBLY__ */
 
 #define PREEMPT_ACTIVE		0x10000000

arch/score/kernel/Makefile

@@ -4,7 +4,7 @@
 
 extra-y	:= head.o vmlinux.lds
 
-obj-y += entry.o init_task.o irq.o process.o ptrace.o \
+obj-y += entry.o irq.o process.o ptrace.o \
 	setup.o signal.o sys_score.o time.o traps.o \
 	sys_call_table.o
 

arch/score/kernel/init_task.c

-/*
- * arch/score/kernel/init_task.c
- *
- * Score Processor version.
- *
- * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, see the file COPYING, or write
- * to the Free Software Foundation, Inc.,
- * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
- */
-
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is THREAD_SIZE aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-EXPORT_SYMBOL(init_task);

arch/sh/Kconfig

@@ -28,6 +28,7 @@ config SUPERH
 	select RTC_LIB
 	select GENERIC_ATOMIC64
 	select GENERIC_IRQ_SHOW
+	select GENERIC_SMP_IDLE_THREAD
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
@@ -152,9 +153,6 @@ config ARCH_NO_VIRT_TO_BUS
 config ARCH_HAS_DEFAULT_IDLE
 	def_bool y
 
-config ARCH_HAS_CPU_IDLE_WAIT
-	def_bool y
-
 config NO_IOPORT
 	def_bool !PCI
 	depends on !SH_CAYMAN && !SH_SH4202_MICRODEV && !SH_SHMIN

arch/sh/Makefile

@@ -124,7 +124,7 @@ endif
 
 export ld-bfd BITS
 
-head-y	:= arch/sh/kernel/init_task.o arch/sh/kernel/head_$(BITS).o
+head-y	:= arch/sh/kernel/head_$(BITS).o
 
 core-y				+= arch/sh/kernel/ arch/sh/mm/ arch/sh/boards/
 core-$(CONFIG_SH_FPU_EMU)	+= arch/sh/math-emu/

arch/sh/include/asm/processor.h

@@ -85,10 +85,6 @@ struct sh_cpuinfo {
 	struct tlb_info itlb;
 	struct tlb_info dtlb;
 
-#ifdef CONFIG_SMP
-	struct task_struct *idle;
-#endif
-
 	unsigned int phys_bits;
 	unsigned long flags;
 } __attribute__ ((aligned(L1_CACHE_BYTES)));
@@ -102,7 +98,6 @@ extern struct sh_cpuinfo cpu_data[];
 #define cpu_relax()	barrier()
 
 void default_idle(void);
-void cpu_idle_wait(void);
 void stop_this_cpu(void *);
 
 /* Forward decl */

arch/sh/include/asm/thread_info.h

@@ -88,22 +88,13 @@ static inline struct thread_info *current_thread_info(void)
 	return ti;
 }
 
-/* thread information allocation */
-#if THREAD_SHIFT >= PAGE_SHIFT
-
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
-#endif
-
-extern struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node);
-extern void free_thread_info(struct thread_info *ti);
 extern void arch_task_cache_init(void);
-#define arch_task_cache_init arch_task_cache_init
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
+extern void arch_release_task_struct(struct task_struct *tsk);
 extern void init_thread_xstate(void);
 
-#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
 #endif /* __ASSEMBLY__ */
 
 /*

arch/sh/kernel/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the Linux/SuperH kernel.
 #
 
-extra-y	:= head_$(BITS).o init_task.o vmlinux.lds
+extra-y	:= head_$(BITS).o vmlinux.lds
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not profile debug and lowlevel utilities

arch/sh/kernel/idle.c

@@ -132,10 +132,6 @@ void __init select_idle_routine(void)
 		pm_idle = poll_idle;
 }
 
-static void do_nothing(void *unused)
-{
-}
-
 void stop_this_cpu(void *unused)
 {
 	local_irq_disable();
@@ -144,19 +140,3 @@ void stop_this_cpu(void *unused)
 	for (;;)
 		cpu_sleep();
 }
-
-/*
- * 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);

arch/sh/kernel/init_task.c

-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/init_task.h>
-#include <linux/mqueue.h>
-#include <linux/fs.h>
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-
-static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
-static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-struct pt_regs fake_swapper_regs;
-/*
- * Initial thread structure.
- *
- * We need to make sure that this is 8192-byte aligned due to the
- * way process stacks are handled. This is done by having a special
- * "init_task" linker map entry..
- */
-union thread_union init_thread_union __init_task_data =
-	{ INIT_THREAD_INFO(init_task) };
-
-/*
- * Initial task structure.
- *
- * All other task structs will be allocated on slabs in fork.c
- */
-struct task_struct init_task = INIT_TASK(init_task);
-
-EXPORT_SYMBOL(init_task);

arch/sh/kernel/process.c

@@ -29,52 +29,10 @@ void free_thread_xstate(struct task_struct *tsk)
 	}
 }
 
-#if THREAD_SHIFT < PAGE_SHIFT
-static struct kmem_cache *thread_info_cache;
-
-struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node)
-{
-	struct thread_info *ti;
-#ifdef CONFIG_DEBUG_STACK_USAGE
-	gfp_t mask = GFP_KERNEL | __GFP_ZERO;
-#else
-	gfp_t mask = GFP_KERNEL;
-#endif
-
-	ti = kmem_cache_alloc_node(thread_info_cache, mask, node);
-	return ti;
-}
-
-void free_thread_info(struct thread_info *ti)
-{
-	free_thread_xstate(ti->task);
-	kmem_cache_free(thread_info_cache, ti);
-}
-
-void thread_info_cache_init(void)
-{
-	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
-					      THREAD_SIZE, SLAB_PANIC, NULL);
-}
-#else
-struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node)
-{
-#ifdef CONFIG_DEBUG_STACK_USAGE
-	gfp_t mask = GFP_KERNEL | __GFP_ZERO;
-#else
-	gfp_t mask = GFP_KERNEL;
-#endif
-	struct page *page = alloc_pages_node(node, mask, THREAD_SIZE_ORDER);
-
-	return page ? page_address(page) : NULL;
-}
-
-void free_thread_info(struct thread_info *ti)
+void arch_release_task_struct(struct task_struct *tsk)
 {
-	free_thread_xstate(ti->task);
-	free_pages((unsigned long)ti, THREAD_SIZE_ORDER);
+	free_thread_xstate(tsk);
 }
-#endif /* THREAD_SHIFT < PAGE_SHIFT */
 
 void arch_task_cache_init(void)
 {