diff options
| -rw-r--r-- | include/linux/mmzone.h | 13 | ||||
| -rw-r--r-- | include/linux/pageblock-flags.h | 51 | ||||
| -rw-r--r-- | mm/page_alloc.c | 111 |
3 files changed, 175 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index f6167f2fd7f..322e8048463 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -13,6 +13,7 @@ #include <linux/init.h> #include <linux/seqlock.h> #include <linux/nodemask.h> +#include <linux/pageblock-flags.h> #include <asm/atomic.h> #include <asm/page.h> @@ -222,6 +223,14 @@ struct zone { #endif struct free_area free_area[MAX_ORDER]; +#ifndef CONFIG_SPARSEMEM + /* + * Flags for a MAX_ORDER_NR_PAGES block. See pageblock-flags.h. + * In SPARSEMEM, this map is stored in struct mem_section + */ + unsigned long *pageblock_flags; +#endif /* CONFIG_SPARSEMEM */ + ZONE_PADDING(_pad1_) @@ -720,6 +729,9 @@ extern struct zone *next_zone(struct zone *zone); #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) +#define SECTION_BLOCKFLAGS_BITS \ + ((SECTION_SIZE_BITS - (MAX_ORDER-1)) * NR_PAGEBLOCK_BITS) + #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS #error Allocator MAX_ORDER exceeds SECTION_SIZE #endif @@ -739,6 +751,7 @@ struct mem_section { * before using it wrong. */ unsigned long section_mem_map; + DECLARE_BITMAP(pageblock_flags, SECTION_BLOCKFLAGS_BITS); }; #ifdef CONFIG_SPARSEMEM_EXTREME diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h new file mode 100644 index 00000000000..96b623f9b4d --- /dev/null +++ b/include/linux/pageblock-flags.h @@ -0,0 +1,51 @@ +/* + * Macros for manipulating and testing flags related to a + * MAX_ORDER_NR_PAGES block of pages. + * + * 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 version 2 of the License + * + * 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. + * + * Copyright (C) IBM Corporation, 2006 + * + * Original author, Mel Gorman + * Major cleanups and reduction of bit operations, Andy Whitcroft + */ +#ifndef PAGEBLOCK_FLAGS_H +#define PAGEBLOCK_FLAGS_H + +#include <linux/types.h> + +/* Macro to aid the definition of ranges of bits */ +#define PB_range(name, required_bits) \ + name, name ## _end = (name + required_bits) - 1 + +/* Bit indices that affect a whole block of pages */ +enum pageblock_bits { + NR_PAGEBLOCK_BITS +}; + +/* Forward declaration */ +struct page; + +/* Declarations for getting and setting flags. See mm/page_alloc.c */ +unsigned long get_pageblock_flags_group(struct page *page, + int start_bitidx, int end_bitidx); +void set_pageblock_flags_group(struct page *page, unsigned long flags, + int start_bitidx, int end_bitidx); + +#define get_pageblock_flags(page) \ + get_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1) +#define set_pageblock_flags(page) \ + set_pageblock_flags_group(page, 0, NR_PAGEBLOCK_BITS-1) + +#endif /* PAGEBLOCK_FLAGS_H */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e69f19e841e..332f46d70d2 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2931,6 +2931,41 @@ static void __meminit calculate_node_totalpages(struct pglist_data *pgdat, realtotalpages); } +#ifndef CONFIG_SPARSEMEM +/* + * Calculate the size of the zone->blockflags rounded to an unsigned long + * Start by making sure zonesize is a multiple of MAX_ORDER-1 by rounding up + * Then figure 1 NR_PAGEBLOCK_BITS worth of bits per MAX_ORDER-1, finally + * round what is now in bits to nearest long in bits, then return it in + * bytes. + */ +static unsigned long __init usemap_size(unsigned long zonesize) +{ + unsigned long usemapsize; + + usemapsize = roundup(zonesize, MAX_ORDER_NR_PAGES); + usemapsize = usemapsize >> (MAX_ORDER-1); + usemapsize *= NR_PAGEBLOCK_BITS; + usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long)); + + return usemapsize / 8; +} + +static void __init setup_usemap(struct pglist_data *pgdat, + struct zone *zone, unsigned long zonesize) +{ + unsigned long usemapsize = usemap_size(zonesize); + zone->pageblock_flags = NULL; + if (usemapsize) { + zone->pageblock_flags = alloc_bootmem_node(pgdat, usemapsize); + memset(zone->pageblock_flags, 0, usemapsize); + } +} +#else +static void inline setup_usemap(struct pglist_data *pgdat, + struct zone *zone, unsigned long zonesize) {} +#endif /* CONFIG_SPARSEMEM */ + /* * Set up the zone data structures: * - mark all pages reserved @@ -3011,6 +3046,7 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat, if (!size) continue; + setup_usemap(pgdat, zone, size); ret = init_currently_empty_zone(zone, zone_start_pfn, size, MEMMAP_EARLY); BUG_ON(ret); @@ -3991,4 +4027,79 @@ EXPORT_SYMBOL(pfn_to_page); EXPORT_SYMBOL(page_to_pfn); #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */ +/* Return a pointer to the bitmap storing bits affecting a block of pages */ +static inline unsigned long *get_pageblock_bitmap(struct zone *zone, + unsigned long pfn) +{ +#ifdef CONFIG_SPARSEMEM + return __pfn_to_section(pfn)->pageblock_flags; +#else + return zone->pageblock_flags; +#endif /* CONFIG_SPARSEMEM */ +} + +static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn) +{ +#ifdef CONFIG_SPARSEMEM + pfn &= (PAGES_PER_SECTION-1); + return (pfn >> (MAX_ORDER-1)) * NR_PAGEBLOCK_BITS; +#else + pfn = pfn - zone->zone_start_pfn; + return (pfn >> (MAX_ORDER-1)) * NR_PAGEBLOCK_BITS; +#endif /* CONFIG_SPARSEMEM */ +} + +/** + * get_pageblock_flags_group - Return the requested group of flags for the MAX_ORDER_NR_PAGES block of pages + * @page: The page within the block of interest + * @start_bitidx: The first bit of interest to retrieve + * @end_bitidx: The last bit of interest + * returns pageblock_bits flags + */ +unsigned long get_pageblock_flags_group(struct page *page, + int start_bitidx, int end_bitidx) +{ + struct zone *zone; + unsigned long *bitmap; + unsigned long pfn, bitidx; + unsigned long flags = 0; + unsigned long value = 1; + + zone = page_zone(page); + pfn = page_to_pfn(page); + bitmap = get_pageblock_bitmap(zone, pfn); + bitidx = pfn_to_bitidx(zone, pfn); + + for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) + if (test_bit(bitidx + start_bitidx, bitmap)) + flags |= value; + return flags; +} + +/** + * set_pageblock_flags_group - Set the requested group of flags for a MAX_ORDER_NR_PAGES block of pages + * @page: The page within the block of interest + * @start_bitidx: The first bit of interest + * @end_bitidx: The last bit of interest + * @flags: The flags to set + */ +void set_pageblock_flags_group(struct page *page, unsigned long flags, + int start_bitidx, int end_bitidx) +{ + struct zone *zone; + unsigned long *bitmap; + unsigned long pfn, bitidx; + unsigned long value = 1; + + zone = page_zone(page); + pfn = page_to_pfn(page); + bitmap = get_pageblock_bitmap(zone, pfn); + bitidx = pfn_to_bitidx(zone, pfn); + + for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) + if (flags & value) + __set_bit(bitidx + start_bitidx, bitmap); + else + __clear_bit(bitidx + start_bitidx, bitmap); +} |