generic debug pagealloc: build fix

This fixes a build failure with generic debug pagealloc:

  mm/debug-pagealloc.c: In function 'set_page_poison':
  mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
  mm/debug-pagealloc.c: In function 'clear_page_poison':
  mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
  mm/debug-pagealloc.c: In function 'page_poison':
  mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
  mm/debug-pagealloc.c: At top level:
  mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
  include/linux/mm.h:1278: error: previous definition of 'kernel_map_pages' was here
  mm/debug-pagealloc.c: In function 'kernel_map_pages':
  mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared (first use in this function)

by fixing

 - debug_flags should be in struct page
 - define DEBUG_PAGEALLOC config option for all architectures
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Reported-by: NAlexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/powerpc/Kconfig.debug

@@ -27,16 +27,6 @@ config DEBUG_STACK_USAGE
 
 	  This option will slow down process creation somewhat.
 
-config DEBUG_PAGEALLOC
-        bool "Debug page memory allocations"
-        depends on DEBUG_KERNEL && !HIBERNATION
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-        help
-          Unmap pages from the kernel linear mapping after free_pages().
-          This results in a large slowdown, but helps to find certain types
-          of memory corruptions.
-
-
 config HCALL_STATS
 	bool "Hypervisor call instrumentation"
 	depends on PPC_PSERIES && DEBUG_FS

arch/s390/Kconfig.debug

@@ -6,13 +6,4 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
-config DEBUG_PAGEALLOC
-	bool "Debug page memory allocations"
-	depends on DEBUG_KERNEL
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	help
-	  Unmap pages from the kernel linear mapping after free_pages().
-	  This results in a slowdown, but helps to find certain types of
-	  memory corruptions.
-
 endmenu

arch/sparc/Kconfig.debug

@@ -22,15 +22,6 @@ config DEBUG_DCFLUSH
 config STACK_DEBUG
 	bool "Stack Overflow Detection Support"
 
-config DEBUG_PAGEALLOC
-	bool "Debug page memory allocations"
-	depends on DEBUG_KERNEL && !HIBERNATION
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	help
-	  Unmap pages from the kernel linear mapping after free_pages().
-	  This results in a large slowdown, but helps to find certain types
-	  of memory corruptions.
-
 config MCOUNT
 	bool
 	depends on SPARC64

arch/x86/Kconfig.debug

@@ -72,15 +72,6 @@ config DEBUG_STACK_USAGE
 
 	  This option will slow down process creation somewhat.
 
-config DEBUG_PAGEALLOC
-	bool "Debug page memory allocations"
-	depends on DEBUG_KERNEL
-	depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
-	---help---
-	  Unmap pages from the kernel linear mapping after free_pages().
-	  This results in a large slowdown, but helps to find certain types
-	  of memory corruptions.
-
 config DEBUG_PER_CPU_MAPS
 	bool "Debug access to per_cpu maps"
 	depends on DEBUG_KERNEL

include/linux/mm_types.h

@@ -95,6 +95,9 @@ struct page {
 	void *virtual;			/* Kernel virtual address (NULL if
 					   not kmapped, ie. highmem) */
 #endif /* WANT_PAGE_VIRTUAL */
+#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
+	unsigned long debug_flags;	/* Use atomic bitops on this */
+#endif
 };
 
 /*
@@ -175,9 +178,6 @@ struct vm_area_struct {
 #ifdef CONFIG_NUMA
 	struct mempolicy *vm_policy;	/* NUMA policy for the VMA */
 #endif
-#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
-	unsigned long debug_flags;	/* Use atomic bitops on this */
-#endif
 };
 
 struct core_thread {

mm/Kconfig.debug

+config DEBUG_PAGEALLOC
+	bool "Debug page memory allocations"
+	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
+	depends on !HIBERNATION || !PPC && !SPARC
+	---help---
+	  Unmap pages from the kernel linear mapping after free_pages().
+	  This results in a large slowdown, but helps to find certain types
+	  of memory corruptions.
+
 config WANT_PAGE_DEBUG_FLAGS
 	bool