#ifndef _LINUX_MMZONE_H #define _LINUX_MMZONE_H #ifdef __KERNEL__ #ifndef __ASSEMBLY__ #include #include #include #include #include #include #include #include #include #include /* Free memory management - zoned buddy allocator. */ #ifndef CONFIG_FORCE_MAX_ZONEORDER #define MAX_ORDER 11 #else #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER #endif struct free_area { struct list_head free_list; unsigned long nr_free; }; struct pglist_data; /* * zone->lock and zone->lru_lock are two of the hottest locks in the kernel. * So add a wild amount of padding here to ensure that they fall into separate * cachelines. There are very few zone structures in the machine, so space * consumption is not a concern here. */ #if defined(CONFIG_SMP) struct zone_padding { char x[0]; } ____cacheline_maxaligned_in_smp; #define ZONE_PADDING(name) struct zone_padding name; #else #define ZONE_PADDING(name) #endif struct per_cpu_pages { int count; /* number of pages in the list */ int low; /* low watermark, refill needed */ int high; /* high watermark, emptying needed */ int batch; /* chunk size for buddy add/remove */ struct list_head list; /* the list of pages */ }; struct per_cpu_pageset { struct per_cpu_pages pcp[2]; /* 0: hot. 1: cold */ #ifdef CONFIG_NUMA unsigned long numa_hit; /* allocated in intended node */ unsigned long numa_miss; /* allocated in non intended node */ unsigned long numa_foreign; /* was intended here, hit elsewhere */ unsigned long interleave_hit; /* interleaver prefered this zone */ unsigned long local_node; /* allocation from local node */ unsigned long other_node; /* allocation from other node */ #endif } ____cacheline_aligned_in_smp; #ifdef CONFIG_NUMA #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)]) #else #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)]) #endif #define ZONE_DMA 0 #define ZONE_DMA32 1 #define ZONE_NORMAL 2 #define ZONE_HIGHMEM 3 #define MAX_NR_ZONES 4 /* Sync this with ZONES_SHIFT */ #define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */ /* * 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. GFP_ZONEMASK defines which bits within * the gfp_mask should be considered as zone modifiers. Each valid * combination of the zone modifier bits has a corresponding list * of zones (in node_zonelists). Thus for two zone modifiers there * will be a maximum of 4 (2 ** 2) zonelists, for 3 modifiers there will * be 8 (2 ** 3) zonelists. GFP_ZONETYPES defines the number of possible * combinations of zone modifiers in "zone modifier space". * * NOTE! Make sure this matches the zones in */ #define GFP_ZONEMASK 0x07 #define GFP_ZONETYPES 5 /* * On machines where it is needed (eg PCs) we divide physical memory * into multiple physical zones. On a PC we have 4 zones: * * ZONE_DMA < 16 MB ISA DMA capable memory * ZONE_DMA32 0 MB Empty * ZONE_NORMAL 16-896 MB direct mapped by the kernel * ZONE_HIGHMEM > 896 MB only page cache and user processes */ struct zone { /* Fields commonly accessed by the page allocator */ unsigned long free_pages; unsigned long pages_min, pages_low, pages_high; /* * We don't know if the memory that we're going to allocate will be freeable * or/and it will be released eventually, so to avoid totally wasting several * GB of ram we must reserve some of the lower zone memory (otherwise we risk * to run OOM on the lower zones despite there's tons of freeable ram * on the higher zones). This array is recalculated at runtime if the * sysctl_lowmem_reserve_ratio sysctl changes. */ unsigned long lowmem_reserve[MAX_NR_ZONES]; #ifdef CONFIG_NUMA struct per_cpu_pageset *pageset[NR_CPUS]; #else struct per_cpu_pageset pageset[NR_CPUS]; #endif /* * free areas of different sizes */ spinlock_t lock; #ifdef CONFIG_MEMORY_HOTPLUG /* see spanned/present_pages for more description */ seqlock_t span_seqlock; #endif struct free_area free_area[MAX_ORDER]; ZONE_PADDING(_pad1_) /* Fields commonly accessed by the page reclaim scanner */ spinlock_t lru_lock; struct list_head active_list; struct list_head inactive_list; unsigned long nr_scan_active; unsigned long nr_scan_inactive; unsigned long nr_active; unsigned long nr_inactive; unsigned long pages_scanned; /* since last reclaim */ int all_unreclaimable; /* All pages pinned */ /* * Does the allocator try to reclaim pages from the zone as soon * as it fails a watermark_ok() in __alloc_pages? */ int reclaim_pages; /* A count of how many reclaimers are scanning this zone */ atomic_t reclaim_in_progress; /* * prev_priority holds the scanning priority for this zone. It is * defined as the scanning priority at which we achieved our reclaim * target at the previous try_to_free_pages() or balance_pgdat() * invokation. * * We use prev_priority as a measure of how much stress page reclaim is * under - it drives the swappiness decision: whether to unmap mapped * pages. * * temp_priority is used to remember the scanning priority at which * this zone was successfully refilled to free_pages == pages_high. * * Access to both these fields is quite racy even on uniprocessor. But * it is expected to average out OK. */ int temp_priority; int prev_priority; ZONE_PADDING(_pad2_) /* Rarely used or read-mostly fields */ /* * wait_table -- the array holding the hash table * wait_table_size -- the size of the hash table array * wait_table_bits -- wait_table_size == (1 << wait_table_bits) * * The purpose of all these is to keep track of the people * waiting for a page to become available and make them * runnable again when possible. The trouble is that this * consumes a lot of space, especially when so few things * wait on pages at a given time. So instead of using * per-page waitqueues, we use a waitqueue hash table. * * The bucket discipline is to sleep on the same queue when * colliding and wake all in that wait queue when removing. * When something wakes, it must check to be sure its page is * truly available, a la thundering herd. The cost of a * collision is great, but given the expected load of the * table, they should be so rare as to be outweighed by the * benefits from the saved space. * * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the * primary users of these fields, and in mm/page_alloc.c * free_area_init_core() performs the initialization of them. */ wait_queue_head_t * wait_table; unsigned long wait_table_size; unsigned long wait_table_bits; /* * Discontig memory support fields. */ struct pglist_data *zone_pgdat; struct page *zone_mem_map; /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ unsigned long zone_start_pfn; /* * zone_start_pfn, spanned_pages and present_pages are all * protected by span_seqlock. It is a seqlock because it has * to be read outside of zone->lock, and it is done in the main * allocator path. But, it is written quite infrequently. * * The lock is declared along with zone->lock because it is * frequently read in proximity to zone->lock. It's good to * give them a chance of being in the same cacheline. */ unsigned long spanned_pages; /* total size, including holes */ unsigned long present_pages; /* amount of memory (excluding holes) */ /* * rarely used fields: */ char *name; } ____cacheline_maxaligned_in_smp; /* * The "priority" of VM scanning is how much of the queues we will scan in one * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the * queues ("queue_length >> 12") during an aging round. */ #define DEF_PRIORITY 12 /* * One allocation request operates on a zonelist. A zonelist * is a list of zones, the first one is the 'goal' of the * allocation, the other zones are fallback zones, in decreasing * priority. * * Right now a zonelist takes up less than a cacheline. We never * modify it apart from boot-up, and only a few indices are used, * so despite the zonelist table being relatively big, the cache * footprint of this construct is very small. */ struct zonelist { struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited }; /* * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM * (mostly NUMA machines?) to denote a higher-level memory zone than the * zone denotes. * * On NUMA machines, each NUMA node would have a pg_data_t to describe * it's memory layout. * * Memory statistics and page replacement data structures are maintained on a * per-zone basis. */ struct bootmem_data; typedef struct pglist_data { struct zone node_zones[MAX_NR_ZONES]; struct zonelist node_zonelists[GFP_ZONETYPES]; int nr_zones; #ifdef CONFIG_FLAT_NODE_MEM_MAP struct page *node_mem_map; #endif struct bootmem_data *bdata; #ifdef CONFIG_MEMORY_HOTPLUG /* * Must be held any time you expect node_start_pfn, node_present_pages * or node_spanned_pages stay constant. Holding this will also * guarantee that any pfn_valid() stays that way. * * Nests above zone->lock and zone->size_seqlock. */ spinlock_t node_size_lock; #endif unsigned long node_start_pfn; unsigned long node_present_pages; /* total number of physical pages */ unsigned long node_spanned_pages; /* total size of physical page range, including holes */ int node_id; struct pglist_data *pgdat_next; wait_queue_head_t kswapd_wait; struct task_struct *kswapd; int kswapd_max_order; } pg_data_t; #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) #ifdef CONFIG_FLAT_NODE_MEM_MAP #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) #else #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) #endif #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) #include extern struct pglist_data *pgdat_list; void __get_zone_counts(unsigned long *active, unsigned long *inactive, unsigned long *free, struct pglist_data *pgdat); void get_zone_counts(unsigned long *active, unsigned long *inactive, unsigned long *free); void build_all_zonelists(void); void wakeup_kswapd(struct zone *zone, int order); int zone_watermark_ok(struct zone *z, int order, unsigned long mark, int classzone_idx, int alloc_flags); #ifdef CONFIG_HAVE_MEMORY_PRESENT void memory_present(int nid, unsigned long start, unsigned long end); #else static inline void memory_present(int nid, unsigned long start, unsigned long end) {} #endif #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); #endif /* * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. */ #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) /** * for_each_pgdat - helper macro to iterate over all nodes * @pgdat - pointer to a pg_data_t variable * * Meant to help with common loops of the form * pgdat = pgdat_list; * while(pgdat) { * ... * pgdat = pgdat->pgdat_next; * } */ #define for_each_pgdat(pgdat) \ for (pgdat = pgdat_list; pgdat; pgdat = pgdat->pgdat_next) /* * next_zone - helper magic for for_each_zone() * Thanks to William Lee Irwin III for this piece of ingenuity. */ static inline struct zone *next_zone(struct zone *zone) { pg_data_t *pgdat = zone->zone_pgdat; if (zone < pgdat->node_zones + MAX_NR_ZONES - 1) zone++; else if (pgdat->pgdat_next) { pgdat = pgdat->pgdat_next; zone = pgdat->node_zones; } else zone = NULL; return zone; } /** * for_each_zone - helper macro to iterate over all memory zones * @zone - pointer to struct zone variable * * The user only needs to declare the zone variable, for_each_zone * fills it in. This basically means for_each_zone() is an * easier to read version of this piece of code: * * for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next) * for (i = 0; i < MAX_NR_ZONES; ++i) { * struct zone * z = pgdat->node_zones + i; * ... * } * } */ #define for_each_zone(zone) \ for (zone = pgdat_list->node_zones; zone; zone = next_zone(zone)) static inline int is_highmem_idx(int idx) { return (idx == ZONE_HIGHMEM); } static inline int is_normal_idx(int idx) { return (idx == ZONE_NORMAL); } /** * is_highmem - helper function to quickly check if a struct zone is a * highmem zone or not. This is an attempt to keep references * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. * @zone - pointer to struct zone variable */ static inline int is_highmem(struct zone *zone) { return zone == zone->zone_pgdat->node_zones + ZONE_HIGHMEM; } static inline int is_normal(struct zone *zone) { return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL; } /* These two functions are used to setup the per zone pages min values */ struct ctl_table; struct file; int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1]; int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); #include /* Returns the number of the current Node. */ #ifndef numa_node_id #define numa_node_id() (cpu_to_node(raw_smp_processor_id())) #endif #ifndef CONFIG_NEED_MULTIPLE_NODES extern struct pglist_data contig_page_data; #define NODE_DATA(nid) (&contig_page_data) #define NODE_MEM_MAP(nid) mem_map #define MAX_NODES_SHIFT 1 #else /* CONFIG_NEED_MULTIPLE_NODES */ #include #endif /* !CONFIG_NEED_MULTIPLE_NODES */ #ifdef CONFIG_SPARSEMEM #include #endif #if BITS_PER_LONG == 32 /* * with 32 bit page->flags field, we reserve 9 bits for node/zone info. * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes. */ #define FLAGS_RESERVED 9 #elif BITS_PER_LONG == 64 /* * with 64 bit flags field, there's plenty of room. */ #define FLAGS_RESERVED 32 #else #error BITS_PER_LONG not defined #endif #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID #define early_pfn_to_nid(nid) (0UL) #endif #ifdef CONFIG_FLATMEM #define pfn_to_nid(pfn) (0) #endif #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT) #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT) #ifdef CONFIG_SPARSEMEM /* * SECTION_SHIFT #bits space required to store a section # * * 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) #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS #error Allocator MAX_ORDER exceeds SECTION_SIZE #endif struct page; struct mem_section { /* * This is, logically, a pointer to an array of struct * pages. However, it is stored with some other magic. * (see sparse.c::sparse_init_one_section()) * * Making it a UL at least makes someone do a cast * before using it wrong. */ unsigned long section_mem_map; }; #ifdef CONFIG_SPARSEMEM_EXTREME #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) #else #define SECTIONS_PER_ROOT 1 #endif #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) #define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT) #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) #ifdef CONFIG_SPARSEMEM_EXTREME extern struct mem_section *mem_section[NR_SECTION_ROOTS]; #else extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; #endif static inline struct mem_section *__nr_to_section(unsigned long nr) { if (!mem_section[SECTION_NR_TO_ROOT(nr)]) return NULL; return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } extern int __section_nr(struct mem_section* ms); /* * We use the lower bits of the mem_map pointer to store * a little bit of information. There should be at least * 3 bits here due to 32-bit alignment. */ #define SECTION_MARKED_PRESENT (1UL<<0) #define SECTION_HAS_MEM_MAP (1UL<<1) #define SECTION_MAP_LAST_BIT (1UL<<2) #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) static inline struct page *__section_mem_map_addr(struct mem_section *section) { unsigned long map = section->section_mem_map; map &= SECTION_MAP_MASK; return (struct page *)map; } static inline int valid_section(struct mem_section *section) { return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); } static inline int section_has_mem_map(struct mem_section *section) { return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); } static inline int valid_section_nr(unsigned long nr) { return valid_section(__nr_to_section(nr)); } static inline struct mem_section *__pfn_to_section(unsigned long pfn) { return __nr_to_section(pfn_to_section_nr(pfn)); } #define pfn_to_page(pfn) \ ({ \ unsigned long __pfn = (pfn); \ __section_mem_map_addr(__pfn_to_section(__pfn)) + __pfn; \ }) #define page_to_pfn(page) \ ({ \ page - __section_mem_map_addr(__nr_to_section( \ page_to_section(page))); \ }) static inline int pfn_valid(unsigned long pfn) { if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; return valid_section(__nr_to_section(pfn_to_section_nr(pfn))); } /* * These are _only_ used during initialisation, therefore they * can use __initdata ... They could have names to indicate * this restriction. */ #ifdef CONFIG_NUMA #define pfn_to_nid early_pfn_to_nid #else #define pfn_to_nid(pfn) (0) #endif #define early_pfn_valid(pfn) pfn_valid(pfn) void sparse_init(void); #else #define sparse_init() do {} while (0) #define sparse_index_init(_sec, _nid) do {} while (0) #endif /* CONFIG_SPARSEMEM */ #ifndef early_pfn_valid #define early_pfn_valid(pfn) (1) #endif void memory_present(int nid, unsigned long start, unsigned long end); unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long); #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _LINUX_MMZONE_H */