From b38f9039efb0745705e7df96868e94b2b66b5759 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 20 Feb 2013 13:14:37 +1100 Subject: [PATCH] mm: move page flags layout to separate header This is a preparation patch for moving page->_last_nid into page->flags that moves page flag layout information to a separate header. This patch is necessary because otherwise there would be a circular dependency between mm_types.h and mm.h. Signed-off-by: Mel Gorman Cc: Peter Zijlstra Cc: Andrea Arcangeli Cc: Ingo Molnar Cc: Simon Jeons Cc: Wanpeng Li Cc: Hugh Dickins Signed-off-by: Andrew Morton --- include/linux/mm.h | 40 ----------------- include/linux/mm_types.h | 1 + include/linux/mmzone.h | 22 +--------- include/linux/page-flags-layout.h | 71 +++++++++++++++++++++++++++++++ 4 files changed, 73 insertions(+), 61 deletions(-) create mode 100644 include/linux/page-flags-layout.h diff --git a/include/linux/mm.h b/include/linux/mm.h index cbfa9661bca4..9f11171971d8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -583,51 +583,11 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) * sets it, so none of the operations on it need to be atomic. */ - -/* - * page->flags layout: - * - * There are three possibilities for how page->flags get - * laid out. The first is for the normal case, without - * sparsemem. The second is for sparsemem when there is - * plenty of space for node and section. The last is when - * we have run out of space and have to fall back to an - * alternate (slower) way of determining the node. - * - * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS | - * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS | - * classic sparse no space for node: | SECTION | ZONE | ... | FLAGS | - */ -#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) -#define SECTIONS_WIDTH SECTIONS_SHIFT -#else -#define SECTIONS_WIDTH 0 -#endif - -#define ZONES_WIDTH ZONES_SHIFT - -#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS -#define NODES_WIDTH NODES_SHIFT -#else -#ifdef CONFIG_SPARSEMEM_VMEMMAP -#error "Vmemmap: No space for nodes field in page flags" -#endif -#define NODES_WIDTH 0 -#endif - /* Page flags: | [SECTION] | [NODE] | ZONE | ... | FLAGS | */ #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH) #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) -/* - * We are going to use the flags for the page to node mapping if its in - * there. This includes the case where there is no node, so it is implicit. - */ -#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0) -#define NODE_NOT_IN_PAGE_FLAGS -#endif - /* * Define the bit shifts to access each section. For non-existent * sections we define the shift as 0; that plus a 0 mask ensures diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 47047cb4d8e5..d05d632c716e 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -12,6 +12,7 @@ #include #include #include +#include #include #include diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4f4c8c26fa9d..6c80d0ac14dd 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -15,7 +15,7 @@ #include #include #include -#include +#include #include #include @@ -310,24 +310,6 @@ enum zone_type { #ifndef __GENERATING_BOUNDS_H -/* - * When a memory allocation must conform to specific limitations (such - * as being suitable for DMA) the caller will pass in hints to the - * allocator in the gfp_mask, in the zone modifier bits. These bits - * are used to select a priority ordered list of memory zones which - * match the requested limits. See gfp_zone() in include/linux/gfp.h - */ - -#if MAX_NR_ZONES < 2 -#define ZONES_SHIFT 0 -#elif MAX_NR_ZONES <= 2 -#define ZONES_SHIFT 1 -#elif MAX_NR_ZONES <= 4 -#define ZONES_SHIFT 2 -#else -#error ZONES_SHIFT -- too many zones configured adjust calculation -#endif - struct zone { /* Fields commonly accessed by the page allocator */ @@ -1055,8 +1037,6 @@ static inline unsigned long early_pfn_to_nid(unsigned long pfn) * PA_SECTION_SHIFT physical address to/from section number * PFN_SECTION_SHIFT pfn to/from section number */ -#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) - #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h new file mode 100644 index 000000000000..316805d6ba1b --- /dev/null +++ b/include/linux/page-flags-layout.h @@ -0,0 +1,71 @@ +#ifndef PAGE_FLAGS_LAYOUT_H +#define PAGE_FLAGS_LAYOUT_H + +#include +#include + +/* + * When a memory allocation must conform to specific limitations (such + * as being suitable for DMA) the caller will pass in hints to the + * allocator in the gfp_mask, in the zone modifier bits. These bits + * are used to select a priority ordered list of memory zones which + * match the requested limits. See gfp_zone() in include/linux/gfp.h + */ +#if MAX_NR_ZONES < 2 +#define ZONES_SHIFT 0 +#elif MAX_NR_ZONES <= 2 +#define ZONES_SHIFT 1 +#elif MAX_NR_ZONES <= 4 +#define ZONES_SHIFT 2 +#else +#error ZONES_SHIFT -- too many zones configured adjust calculation +#endif + +#ifdef CONFIG_SPARSEMEM +#include + +/* SECTION_SHIFT #bits space required to store a section # */ +#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) + +#endif /* CONFIG_SPARSEMEM */ + +/* + * page->flags layout: + * + * There are three possibilities for how page->flags get + * laid out. The first is for the normal case, without + * sparsemem. The second is for sparsemem when there is + * plenty of space for node and section. The last is when + * we have run out of space and have to fall back to an + * alternate (slower) way of determining the node. + * + * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS | + * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS | + * classic sparse no space for node: | SECTION | ZONE | ... | FLAGS | + */ +#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) +#define SECTIONS_WIDTH SECTIONS_SHIFT +#else +#define SECTIONS_WIDTH 0 +#endif + +#define ZONES_WIDTH ZONES_SHIFT + +#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS +#define NODES_WIDTH NODES_SHIFT +#else +#ifdef CONFIG_SPARSEMEM_VMEMMAP +#error "Vmemmap: No space for nodes field in page flags" +#endif +#define NODES_WIDTH 0 +#endif + +/* + * We are going to use the flags for the page to node mapping if its in + * there. This includes the case where there is no node, so it is implicit. + */ +#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0) +#define NODE_NOT_IN_PAGE_FLAGS +#endif + +#endif /* _LINUX_PAGE_FLAGS_LAYOUT */ -- 2.39.5