diff options
| -rw-r--r-- | include/linux/mm.h | 53 | ||||
| -rw-r--r-- | include/linux/mmzone.h | 19 | ||||
| -rw-r--r-- | mm/page_alloc.c | 2 |
3 files changed, 52 insertions, 22 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 1813b162b0a..57b2ead51db 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -395,19 +395,41 @@ static inline void put_page(struct page *page) /* * The zone field is never updated after free_area_init_core() * sets it, so none of the operations on it need to be atomic. - * We'll have up to (MAX_NUMNODES * MAX_NR_ZONES) zones total, - * so we use (MAX_NODES_SHIFT + MAX_ZONES_SHIFT) here to get enough bits. */ -#define NODEZONE_SHIFT (sizeof(page_flags_t)*8 - MAX_NODES_SHIFT - MAX_ZONES_SHIFT) + +/* Page flags: | NODE | ZONE | ... | FLAGS | */ +#define NODES_PGOFF ((sizeof(page_flags_t)*8) - NODES_SHIFT) +#define ZONES_PGOFF (NODES_PGOFF - ZONES_SHIFT) + +/* + * Define the bit shifts to access each section. For non-existant + * sections we define the shift as 0; that plus a 0 mask ensures + * the compiler will optimise away reference to them. + */ +#define NODES_PGSHIFT (NODES_PGOFF * (NODES_SHIFT != 0)) +#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_SHIFT != 0)) + +/* NODE:ZONE is used to lookup the zone from a page. */ +#define ZONETABLE_SHIFT (NODES_SHIFT + ZONES_SHIFT) +#define ZONETABLE_PGSHIFT ZONES_PGSHIFT + +#if NODES_SHIFT+ZONES_SHIFT > FLAGS_RESERVED +#error NODES_SHIFT+ZONES_SHIFT > FLAGS_RESERVED +#endif + #define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone) +#define ZONES_MASK ((1UL << ZONES_SHIFT) - 1) +#define NODES_MASK ((1UL << NODES_SHIFT) - 1) +#define ZONETABLE_MASK ((1UL << ZONETABLE_SHIFT) - 1) + static inline unsigned long page_zonenum(struct page *page) { - return (page->flags >> NODEZONE_SHIFT) & (~(~0UL << ZONES_SHIFT)); + return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK; } static inline unsigned long page_to_nid(struct page *page) { - return (page->flags >> (NODEZONE_SHIFT + ZONES_SHIFT)); + return (page->flags >> NODES_PGSHIFT) & NODES_MASK; } struct zone; @@ -415,13 +437,26 @@ extern struct zone *zone_table[]; static inline struct zone *page_zone(struct page *page) { - return zone_table[page->flags >> NODEZONE_SHIFT]; + return zone_table[(page->flags >> ZONETABLE_PGSHIFT) & + ZONETABLE_MASK]; +} + +static inline void set_page_zone(struct page *page, unsigned long zone) +{ + page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT); + page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT; +} +static inline void set_page_node(struct page *page, unsigned long node) +{ + page->flags &= ~(NODES_MASK << NODES_PGSHIFT); + page->flags |= (node & NODES_MASK) << NODES_PGSHIFT; } -static inline void set_page_zone(struct page *page, unsigned long nodezone_num) +static inline void set_page_links(struct page *page, unsigned long zone, + unsigned long node) { - page->flags &= ~(~0UL << NODEZONE_SHIFT); - page->flags |= nodezone_num << NODEZONE_SHIFT; + set_page_zone(page, zone); + set_page_node(page, node); } #ifndef CONFIG_DISCONTIGMEM diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index b79633d3a97..39e912708e2 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -414,30 +414,25 @@ extern struct pglist_data contig_page_data; #include <asm/mmzone.h> +#endif /* !CONFIG_DISCONTIGMEM */ + #if BITS_PER_LONG == 32 || defined(ARCH_HAS_ATOMIC_UNSIGNED) /* * with 32 bit page->flags field, we reserve 8 bits for node/zone info. * there are 3 zones (2 bits) and this leaves 8-2=6 bits for nodes. */ -#define MAX_NODES_SHIFT 6 +#define FLAGS_RESERVED 8 + #elif BITS_PER_LONG == 64 /* * with 64 bit flags field, there's plenty of room. */ -#define MAX_NODES_SHIFT 10 -#endif +#define FLAGS_RESERVED 32 -#endif /* !CONFIG_DISCONTIGMEM */ - -#if NODES_SHIFT > MAX_NODES_SHIFT -#error NODES_SHIFT > MAX_NODES_SHIFT -#endif +#else -/* There are currently 3 zones: DMA, Normal & Highmem, thus we need 2 bits */ -#define MAX_ZONES_SHIFT 2 +#error BITS_PER_LONG not defined -#if ZONES_SHIFT > MAX_ZONES_SHIFT -#error ZONES_SHIFT > MAX_ZONES_SHIFT #endif #endif /* !__ASSEMBLY__ */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index bf1dd881909..1958358e29b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1653,7 +1653,7 @@ void __init memmap_init_zone(unsigned long size, int nid, unsigned long zone, struct page *page; for (page = start; page < (start + size); page++) { - set_page_zone(page, NODEZONE(nid, zone)); + set_page_links(page, zone, nid); set_page_count(page, 0); reset_page_mapcount(page); SetPageReserved(page); |