diff --git a/init/Makefile b/init/Makefile
index 4a243df426f7..dc5eeca6eb6d 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-obj-y                          := main.o version.o mounts.o
+obj-y                          := main.o dyn_array.o version.o mounts.o
 ifneq ($(CONFIG_BLK_DEV_INITRD),y)
 obj-y                          += noinitramfs.o
 else
diff --git a/init/dyn_array.c b/init/dyn_array.c
new file mode 100644
index 000000000000..c4cd902a1180
--- /dev/null
+++ b/init/dyn_array.c
@@ -0,0 +1,124 @@
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/kallsyms.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/irq.h>
+
+void __init pre_alloc_dyn_array(void)
+{
+#ifdef CONFIG_HAVE_DYN_ARRAY
+	unsigned long total_size = 0, size, phys;
+	unsigned long max_align = 1;
+	struct dyn_array **daa;
+	char *ptr;
+
+	/* get the total size at first */
+	for (daa = __dyn_array_start ; daa < __dyn_array_end; daa++) {
+		struct dyn_array *da = *daa;
+
+		size = da->size * (*da->nr);
+		print_fn_descriptor_symbol("dyn_array %s ", da->name);
+		printk(KERN_CONT "size:%#lx nr:%d align:%#lx\n",
+			da->size, *da->nr, da->align);
+		total_size += roundup(size, da->align);
+		if (da->align > max_align)
+			max_align = da->align;
+	}
+	if (total_size)
+		printk(KERN_DEBUG "dyn_array total_size: %#lx\n",
+			 total_size);
+	else
+		return;
+
+	/* allocate them all together */
+	max_align = max_t(unsigned long, max_align, PAGE_SIZE);
+	ptr = __alloc_bootmem_nopanic(total_size, max_align, 0);
+	if (!ptr)
+		panic("Can not alloc dyn_alloc\n");
+
+	phys = virt_to_phys(ptr);
+	for (daa = __dyn_array_start ; daa < __dyn_array_end; daa++) {
+		struct dyn_array *da = *daa;
+
+		size = da->size * (*da->nr);
+		print_fn_descriptor_symbol("dyn_array %s ", da->name);
+
+		phys = roundup(phys, da->align);
+		*da->name = phys_to_virt(phys);
+		printk(KERN_CONT " ==> [%#lx - %#lx]\n", phys, phys + size);
+
+		phys += size;
+
+		if (da->init_work)
+			da->init_work(da);
+	}
+#else
+#ifdef CONFIF_GENERIC_HARDIRQS
+	unsigned int i;
+
+	for (i = 0; i < NR_IRQS; i++)
+		irq_desc[i].irq = i;
+#endif
+#endif
+}
+
+unsigned long __init per_cpu_dyn_array_size(unsigned long *align)
+{
+	unsigned long total_size = 0;
+#ifdef CONFIG_HAVE_DYN_ARRAY
+	unsigned long size;
+	struct dyn_array **daa;
+	unsigned max_align = 1;
+
+	for (daa = __per_cpu_dyn_array_start ; daa < __per_cpu_dyn_array_end; daa++) {
+		struct dyn_array *da = *daa;
+
+		size = da->size * (*da->nr);
+		print_fn_descriptor_symbol("per_cpu_dyn_array %s ", da->name);
+		printk(KERN_CONT "size:%#lx nr:%d align:%#lx\n",
+			da->size, *da->nr, da->align);
+		total_size += roundup(size, da->align);
+		if (da->align > max_align)
+			max_align = da->align;
+	}
+	if (total_size) {
+		printk(KERN_DEBUG "per_cpu_dyn_array total_size: %#lx\n",
+			 total_size);
+		*align = max_align;
+	}
+#endif
+	return total_size;
+}
+
+void __init per_cpu_alloc_dyn_array(int cpu, char *ptr)
+{
+#ifdef CONFIG_HAVE_DYN_ARRAY
+	unsigned long size, phys;
+	struct dyn_array **daa;
+	unsigned long addr;
+	void **array;
+
+	phys = virt_to_phys(ptr);
+	for (daa = __per_cpu_dyn_array_start ; daa < __per_cpu_dyn_array_end; daa++) {
+		struct dyn_array *da = *daa;
+
+		size = da->size * (*da->nr);
+		print_fn_descriptor_symbol("per_cpu_dyn_array %s ", da->name);
+
+		phys = roundup(phys, da->align);
+		addr = (unsigned long)da->name;
+		addr += per_cpu_offset(cpu);
+		array = (void **)addr;
+		*array = phys_to_virt(phys);
+		*da->name = *array; /* so init_work could use it directly */
+		printk(KERN_CONT " ==> [%#lx - %#lx]\n", phys, phys + size);
+
+		phys += size;
+
+		if (da->init_work) {
+			da->init_work(da);
+		}
+	}
+#endif
+}
diff --git a/init/main.c b/init/main.c
index 0d2e60144f83..e81cf427d9c7 100644
--- a/init/main.c
+++ b/init/main.c
@@ -542,124 +542,6 @@ void __init __weak thread_info_cache_init(void)
 {
 }
 
-void pre_alloc_dyn_array(void)
-{
-#ifdef CONFIG_HAVE_DYN_ARRAY
-	unsigned long total_size = 0, size, phys;
-	unsigned long max_align = 1;
-	struct dyn_array **daa;
-	char *ptr;
-
-	/* get the total size at first */
-	for (daa = __dyn_array_start ; daa < __dyn_array_end; daa++) {
-		struct dyn_array *da = *daa;
-
-		size = da->size * (*da->nr);
-		print_fn_descriptor_symbol("dyn_array %s ", da->name);
-		printk(KERN_CONT "size:%#lx nr:%d align:%#lx\n",
-			da->size, *da->nr, da->align);
-		total_size += roundup(size, da->align);
-		if (da->align > max_align)
-			max_align = da->align;
-	}
-	if (total_size)
-		printk(KERN_DEBUG "dyn_array total_size: %#lx\n",
-			 total_size);
-	else
-		return;
-
-	/* allocate them all together */
-	max_align = max_t(unsigned long, max_align, PAGE_SIZE);
-	ptr = __alloc_bootmem_nopanic(total_size, max_align, 0);
-	if (!ptr)
-		panic("Can not alloc dyn_alloc\n");
-
-	phys = virt_to_phys(ptr);
-	for (daa = __dyn_array_start ; daa < __dyn_array_end; daa++) {
-		struct dyn_array *da = *daa;
-
-		size = da->size * (*da->nr);
-		print_fn_descriptor_symbol("dyn_array %s ", da->name);
-
-		phys = roundup(phys, da->align);
-		*da->name = phys_to_virt(phys);
-		printk(KERN_CONT " ==> [%#lx - %#lx]\n", phys, phys + size);
-
-		phys += size;
-
-		if (da->init_work)
-			da->init_work(da);
-	}
-#else
-#ifdef CONFIF_GENERIC_HARDIRQS
-	unsigned int i;
-
-	for (i = 0; i < NR_IRQS; i++)
-		irq_desc[i].irq = i;
-#endif
-#endif
-}
-
-unsigned long per_cpu_dyn_array_size(unsigned long *align)
-{
-	unsigned long total_size = 0;
-#ifdef CONFIG_HAVE_DYN_ARRAY
-	unsigned long size;
-	struct dyn_array **daa;
-	unsigned max_align = 1;
-
-	for (daa = __per_cpu_dyn_array_start ; daa < __per_cpu_dyn_array_end; daa++) {
-		struct dyn_array *da = *daa;
-
-		size = da->size * (*da->nr);
-		print_fn_descriptor_symbol("per_cpu_dyn_array %s ", da->name);
-		printk(KERN_CONT "size:%#lx nr:%d align:%#lx\n",
-			da->size, *da->nr, da->align);
-		total_size += roundup(size, da->align);
-		if (da->align > max_align)
-			max_align = da->align;
-	}
-	if (total_size) {
-		printk(KERN_DEBUG "per_cpu_dyn_array total_size: %#lx\n",
-			 total_size);
-		*align = max_align;
-	}
-#endif
-	return total_size;
-}
-
-void per_cpu_alloc_dyn_array(int cpu, char *ptr)
-{
-#ifdef CONFIG_HAVE_DYN_ARRAY
-	unsigned long size, phys;
-	struct dyn_array **daa;
-	unsigned long addr;
-	void **array;
-
-	phys = virt_to_phys(ptr);
-	for (daa = __per_cpu_dyn_array_start ; daa < __per_cpu_dyn_array_end; daa++) {
-		struct dyn_array *da = *daa;
-
-		size = da->size * (*da->nr);
-		print_fn_descriptor_symbol("per_cpu_dyn_array %s ", da->name);
-
-		phys = roundup(phys, da->align);
-		addr = (unsigned long)da->name;
-		addr += per_cpu_offset(cpu);
-		array = (void **)addr;
-		*array = phys_to_virt(phys);
-		*da->name = *array; /* so init_work could use it directly */
-		printk(KERN_CONT " ==> [%#lx - %#lx]\n", phys, phys + size);
-
-		phys += size;
-
-		if (da->init_work) {
-			da->init_work(da);
-		}
-	}
-#endif
-}
-
 asmlinkage void __init start_kernel(void)
 {
 	char * command_line;