Edit File: mmzone.h
#ifndef _LINUX_MMZONE_H #define _LINUX_MMZONE_H #ifndef __ASSEMBLY__ #ifndef __GENERATING_BOUNDS_H #include <linux/spinlock.h> #include <linux/list.h> #include <linux/wait.h> #include <linux/bitops.h> #include <linux/cache.h> #include <linux/threads.h> #include <linux/numa.h> #include <linux/init.h> #include <linux/seqlock.h> #include <linux/nodemask.h> #include <linux/pageblock-flags.h> #include <linux/page-flags-layout.h> #include <linux/atomic.h> #include <asm/page.h> #include <linux/rh_kabi.h> /* Free memory management - zoned buddy allocator. */ #ifndef CONFIG_FORCE_MAX_ZONEORDER #define MAX_ORDER 11 #else #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER #endif #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1)) /* * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed * costly to service. That is between allocation orders which should * coalesce naturally under reasonable reclaim pressure and those which * will not. */ #define PAGE_ALLOC_COSTLY_ORDER 3 enum { MIGRATE_UNMOVABLE, MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ MIGRATE_RESERVE = MIGRATE_PCPTYPES, #ifdef CONFIG_CMA /* * MIGRATE_CMA migration type is designed to mimic the way * ZONE_MOVABLE works. Only movable pages can be allocated * from MIGRATE_CMA pageblocks and page allocator never * implicitly change migration type of MIGRATE_CMA pageblock. * * The way to use it is to change migratetype of a range of * pageblocks to MIGRATE_CMA which can be done by * __free_pageblock_cma() function. What is important though * is that a range of pageblocks must be aligned to * MAX_ORDER_NR_PAGES should biggest page be bigger then * a single pageblock. */ MIGRATE_CMA, #endif #ifdef CONFIG_MEMORY_ISOLATION MIGRATE_ISOLATE, /* can't allocate from here */ #endif MIGRATE_TYPES }; #ifdef CONFIG_CMA # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA) #else # define is_migrate_cma(migratetype) false # define is_migrate_cma_page(_page) false #endif #define for_each_migratetype_order(order, type) \ for (order = 0; order < MAX_ORDER; order++) \ for (type = 0; type < MIGRATE_TYPES; type++) extern int page_group_by_mobility_disabled; static inline int get_pageblock_migratetype(struct page *page) { return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end); } struct free_area { struct list_head free_list[MIGRATE_TYPES]; 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_internodealigned_in_smp; #define ZONE_PADDING(name) struct zone_padding name; #else #define ZONE_PADDING(name) #endif enum zone_stat_item { /* First 128 byte cacheline (assuming 64 bit words) */ NR_FREE_PAGES, NR_ALLOC_BATCH, NR_LRU_BASE, NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ NR_ACTIVE_ANON, /* " " " " " */ NR_INACTIVE_FILE, /* " " " " " */ NR_ACTIVE_FILE, /* " " " " " */ NR_UNEVICTABLE, /* " " " " " */ NR_MLOCK, /* mlock()ed pages found and moved off LRU */ NR_ANON_PAGES, /* Mapped anonymous pages */ NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. only modified from process context */ NR_FILE_PAGES, NR_FILE_DIRTY, NR_WRITEBACK, NR_SLAB_RECLAIMABLE, NR_SLAB_UNRECLAIMABLE, NR_PAGETABLE, /* used for pagetables */ NR_KERNEL_STACK, /* Second 128 byte cacheline */ NR_UNSTABLE_NFS, /* NFS unstable pages */ NR_BOUNCE, NR_VMSCAN_WRITE, NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ NR_DIRTIED, /* page dirtyings since bootup */ NR_WRITTEN, /* page writings since bootup */ #ifdef CONFIG_NUMA NUMA_HIT, /* allocated in intended node */ NUMA_MISS, /* allocated in non intended node */ NUMA_FOREIGN, /* was intended here, hit elsewhere */ NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ NUMA_LOCAL, /* allocation from local node */ NUMA_OTHER, /* allocation from other node */ #endif WORKINGSET_REFAULT, WORKINGSET_ACTIVATE, WORKINGSET_NODERECLAIM, NR_ANON_TRANSPARENT_HUGEPAGES, NR_FREE_CMA_PAGES, NR_VM_ZONE_STAT_ITEMS }; /* * We do arithmetic on the LRU lists in various places in the code, * so it is important to keep the active lists LRU_ACTIVE higher in * the array than the corresponding inactive lists, and to keep * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. * * This has to be kept in sync with the statistics in zone_stat_item * above and the descriptions in vmstat_text in mm/vmstat.c */ #define LRU_BASE 0 #define LRU_ACTIVE 1 #define LRU_FILE 2 enum lru_list { LRU_INACTIVE_ANON = LRU_BASE, LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, LRU_UNEVICTABLE, NR_LRU_LISTS }; #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) static inline int is_file_lru(enum lru_list lru) { return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); } static inline int is_active_lru(enum lru_list lru) { return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); } static inline int is_unevictable_lru(enum lru_list lru) { return (lru == LRU_UNEVICTABLE); } struct zone_reclaim_stat { /* * The pageout code in vmscan.c keeps track of how many of the * mem/swap backed and file backed pages are referenced. * The higher the rotated/scanned ratio, the more valuable * that cache is. * * The anon LRU stats live in [0], file LRU stats in [1] */ unsigned long recent_rotated[2]; unsigned long recent_scanned[2]; }; struct lruvec { struct list_head lists[NR_LRU_LISTS]; struct zone_reclaim_stat reclaim_stat; #ifdef CONFIG_MEMCG struct zone *zone; #endif }; /* Mask used at gathering information at once (see memcontrol.c) */ #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE)) #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON)) #define LRU_ALL ((1 << NR_LRU_LISTS) - 1) /* Isolate unmapped file */ #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) /* Isolate for asynchronous migration */ #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) /* Isolate unevictable pages */ #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) /* LRU Isolation modes. */ typedef unsigned __bitwise__ isolate_mode_t; enum zone_watermarks { WMARK_MIN, WMARK_LOW, WMARK_HIGH, NR_WMARK }; #define min_wmark_pages(z) (z->watermark[WMARK_MIN]) #define low_wmark_pages(z) (z->watermark[WMARK_LOW]) #define high_wmark_pages(z) (z->watermark[WMARK_HIGH]) struct per_cpu_pages { int count; /* number of pages in the list */ int high; /* high watermark, emptying needed */ int batch; /* chunk size for buddy add/remove */ /* Lists of pages, one per migrate type stored on the pcp-lists */ struct list_head lists[MIGRATE_PCPTYPES]; }; struct per_cpu_pageset { struct per_cpu_pages pcp; #ifdef CONFIG_NUMA s8 expire; #endif #ifdef CONFIG_SMP s8 stat_threshold; s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; #endif }; #endif /* !__GENERATING_BOUNDS.H */ enum zone_type { #ifdef CONFIG_ZONE_DMA /* * ZONE_DMA is used when there are devices that are not able * to do DMA to all of addressable memory (ZONE_NORMAL). Then we * carve out the portion of memory that is needed for these devices. * The range is arch specific. * * Some examples * * Architecture Limit * --------------------------- * parisc, ia64, sparc <4G * s390 <2G * arm Various * alpha Unlimited or 0-16MB. * * i386, x86_64 and multiple other arches * <16M. */ ZONE_DMA, #endif #ifdef CONFIG_ZONE_DMA32 /* * x86_64 needs two ZONE_DMAs because it supports devices that are * only able to do DMA to the lower 16M but also 32 bit devices that * can only do DMA areas below 4G. */ ZONE_DMA32, #endif /* * Normal addressable memory is in ZONE_NORMAL. DMA operations can be * performed on pages in ZONE_NORMAL if the DMA devices support * transfers to all addressable memory. */ ZONE_NORMAL, #ifdef CONFIG_HIGHMEM /* * A memory area that is only addressable by the kernel through * mapping portions into its own address space. This is for example * used by i386 to allow the kernel to address the memory beyond * 900MB. The kernel will set up special mappings (page * table entries on i386) for each page that the kernel needs to * access. */ ZONE_HIGHMEM, #endif ZONE_MOVABLE, /* * RHEL: we cannot grow MAX_NR_ZONES (see below) and need to * encode ZONE_DEVICE another way. */ __MAX_NR_ZONES #ifndef __GENKSYMS__ , #ifdef CONFIG_ZONE_DEVICE ZONE_DEVICE = __MAX_NR_ZONES, REAL_MAX_ZONES, #else REAL_MAX_ZONES = __MAX_NR_ZONES, #endif #endif }; #ifndef __GENERATING_BOUNDS_H struct zone { /* Fields commonly accessed by the page allocator */ /* zone watermarks, access with *_wmark_pages(zone) macros */ unsigned long watermark[NR_WMARK]; /* * When free pages are below this point, additional steps are taken * when reading the number of free pages to avoid per-cpu counter * drift allowing watermarks to be breached */ unsigned long percpu_drift_mark; /* * 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]; /* * This is a per-zone reserve of pages that should not be * considered dirtyable memory. */ unsigned long dirty_balance_reserve; #ifdef CONFIG_NUMA int node; /* * zone reclaim becomes active if more unmapped pages exist. */ unsigned long min_unmapped_pages; unsigned long min_slab_pages; #endif struct per_cpu_pageset __percpu *pageset; /* * free areas of different sizes */ spinlock_t lock; /* * RHEL7 note: all_unreclaimable is not used anymore * but we're keeping the member in place to not mess up * with struct zone layout and KABI expectations. */ int all_unreclaimable; /* All pages pinned */ #if defined CONFIG_COMPACTION || defined CONFIG_CMA /* Set to true when the PG_migrate_skip bits should be cleared */ bool compact_blockskip_flush; /* pfns where compaction scanners should start */ unsigned long compact_cached_free_pfn; unsigned long compact_cached_migrate_pfn; #endif #ifdef CONFIG_MEMORY_HOTPLUG /* see spanned/present_pages for more description */ seqlock_t span_seqlock; #endif struct free_area free_area[MAX_ORDER]; #ifndef CONFIG_SPARSEMEM /* * Flags for a pageblock_nr_pages block. See pageblock-flags.h. * In SPARSEMEM, this map is stored in struct mem_section */ unsigned long *pageblock_flags; #endif /* CONFIG_SPARSEMEM */ #ifdef CONFIG_COMPACTION /* * On compaction failure, 1<<compact_defer_shift compactions * are skipped before trying again. The number attempted since * last failure is tracked with compact_considered. */ unsigned int compact_considered; unsigned int compact_defer_shift; int compact_order_failed; #endif ZONE_PADDING(_pad1_) /* Fields commonly accessed by the page reclaim scanner */ spinlock_t lru_lock; struct lruvec lruvec; /* Evictions & activations on the inactive file list */ atomic_long_t inactive_age; unsigned long pages_scanned; /* since last reclaim */ unsigned long flags; /* zone flags, see below */ /* Zone statistics */ atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; /* * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on * this zone's LRU. Maintained by the pageout code. */ unsigned int inactive_ratio; ZONE_PADDING(_pad2_) /* Rarely used or read-mostly fields */ /* * wait_table -- the array holding the hash table * wait_table_hash_nr_entries -- 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_hash_nr_entries; unsigned long wait_table_bits; /* * Discontig memory support fields. */ struct pglist_data *zone_pgdat; /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ unsigned long zone_start_pfn; /* * spanned_pages is the total pages spanned by the zone, including * holes, which is calculated as: * spanned_pages = zone_end_pfn - zone_start_pfn; * * present_pages is physical pages existing within the zone, which * is calculated as: * present_pages = spanned_pages - absent_pages(pages in holes); * * managed_pages is present pages managed by the buddy system, which * is calculated as (reserved_pages includes pages allocated by the * bootmem allocator): * managed_pages = present_pages - reserved_pages; * * So present_pages may be used by memory hotplug or memory power * management logic to figure out unmanaged pages by checking * (present_pages - managed_pages). And managed_pages should be used * by page allocator and vm scanner to calculate all kinds of watermarks * and thresholds. * * Locking rules: * * zone_start_pfn and spanned_pages are 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 span_seq 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. * * Write access to present_pages at runtime should be protected by * mem_hotplug_begin/end(). Any reader who can't tolerant drift of * present_pages should get_online_mems() to get a stable value. * * Read access to managed_pages should be safe because it's unsigned * long. Write access to zone->managed_pages and totalram_pages are * protected by managed_page_count_lock at runtime. Idealy only * adjust_managed_page_count() should be used instead of directly * touching zone->managed_pages and totalram_pages. */ unsigned long spanned_pages; unsigned long present_pages; unsigned long managed_pages; /* * Number of MIGRATE_RESEVE page block. To maintain for just * optimization. Protected by zone->lock. */ int nr_migrate_reserve_block; /* * rarely used fields: */ const char *name; /* reserved for Red Hat */ RH_KABI_RESERVE(1) RH_KABI_RESERVE(2) RH_KABI_RESERVE(3) RH_KABI_RESERVE(4) RH_KABI_RESERVE(5) RH_KABI_RESERVE(6) RH_KABI_RESERVE(7) RH_KABI_RESERVE(8) } ____cacheline_internodealigned_in_smp; typedef enum { ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */ ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */ ZONE_CONGESTED, /* zone has many dirty pages backed by * a congested BDI */ ZONE_TAIL_LRU_DIRTY, /* reclaim scanning has recently found * many dirty file pages at the tail * of the LRU. */ ZONE_WRITEBACK, /* reclaim scanning has recently found * many pages under writeback */ } zone_flags_t; static inline void zone_set_flag(struct zone *zone, zone_flags_t flag) { set_bit(flag, &zone->flags); } static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag) { return test_and_set_bit(flag, &zone->flags); } static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag) { clear_bit(flag, &zone->flags); } static inline int zone_is_reclaim_congested(const struct zone *zone) { return test_bit(ZONE_CONGESTED, &zone->flags); } static inline int zone_is_reclaim_dirty(const struct zone *zone) { return test_bit(ZONE_TAIL_LRU_DIRTY, &zone->flags); } static inline int zone_is_reclaim_writeback(const struct zone *zone) { return test_bit(ZONE_WRITEBACK, &zone->flags); } static inline int zone_is_reclaim_locked(const struct zone *zone) { return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags); } static inline int zone_is_oom_locked(const struct zone *zone) { return test_bit(ZONE_OOM_LOCKED, &zone->flags); } static inline unsigned long zone_end_pfn(const struct zone *zone) { return zone->zone_start_pfn + zone->spanned_pages; } static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) { return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); } static inline bool zone_is_initialized(struct zone *zone) { return !!zone->wait_table; } static inline bool zone_is_empty(struct zone *zone) { return zone->spanned_pages == 0; } /* * 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 /* Maximum number of zones on a zonelist */ #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) #ifdef CONFIG_NUMA /* * The NUMA zonelists are doubled because we need zonelists that restrict the * allocations to a single node for __GFP_THISNODE. * * [0] : Zonelist with fallback * [1] : No fallback (__GFP_THISNODE) */ #define MAX_ZONELISTS 2 /* * We cache key information from each zonelist for smaller cache * footprint when scanning for free pages in get_page_from_freelist(). * * 1) The BITMAP fullzones tracks which zones in a zonelist have come * up short of free memory since the last time (last_fullzone_zap) * we zero'd fullzones. * 2) The array z_to_n[] maps each zone in the zonelist to its node * id, so that we can efficiently evaluate whether that node is * set in the current tasks mems_allowed. * * Both fullzones and z_to_n[] are one-to-one with the zonelist, * indexed by a zones offset in the zonelist zones[] array. * * The get_page_from_freelist() routine does two scans. During the * first scan, we skip zones whose corresponding bit in 'fullzones' * is set or whose corresponding node in current->mems_allowed (which * comes from cpusets) is not set. During the second scan, we bypass * this zonelist_cache, to ensure we look methodically at each zone. * * Once per second, we zero out (zap) fullzones, forcing us to * reconsider nodes that might have regained more free memory. * The field last_full_zap is the time we last zapped fullzones. * * This mechanism reduces the amount of time we waste repeatedly * reexaming zones for free memory when they just came up low on * memory momentarilly ago. * * The zonelist_cache struct members logically belong in struct * zonelist. However, the mempolicy zonelists constructed for * MPOL_BIND are intentionally variable length (and usually much * shorter). A general purpose mechanism for handling structs with * multiple variable length members is more mechanism than we want * here. We resort to some special case hackery instead. * * The MPOL_BIND zonelists don't need this zonelist_cache (in good * part because they are shorter), so we put the fixed length stuff * at the front of the zonelist struct, ending in a variable length * zones[], as is needed by MPOL_BIND. * * Then we put the optional zonelist cache on the end of the zonelist * struct. This optional stuff is found by a 'zlcache_ptr' pointer in * the fixed length portion at the front of the struct. This pointer * both enables us to find the zonelist cache, and in the case of * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL) * to know that the zonelist cache is not there. * * The end result is that struct zonelists come in two flavors: * 1) The full, fixed length version, shown below, and * 2) The custom zonelists for MPOL_BIND. * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache. * * Even though there may be multiple CPU cores on a node modifying * fullzones or last_full_zap in the same zonelist_cache at the same * time, we don't lock it. This is just hint data - if it is wrong now * and then, the allocator will still function, perhaps a bit slower. */ struct zonelist_cache { unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */ DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */ unsigned long last_full_zap; /* when last zap'd (jiffies) */ }; #else #define MAX_ZONELISTS 1 struct zonelist_cache; #endif /* * This struct contains information about a zone in a zonelist. It is stored * here to avoid dereferences into large structures and lookups of tables */ struct zoneref { struct zone *zone; /* Pointer to actual zone */ int zone_idx; /* zone_idx(zoneref->zone) */ }; /* * 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. * * If zlcache_ptr is not NULL, then it is just the address of zlcache, * as explained above. If zlcache_ptr is NULL, there is no zlcache. * * * To speed the reading of the zonelist, the zonerefs contain the zone index * of the entry being read. Helper functions to access information given * a struct zoneref are * * zonelist_zone() - Return the struct zone * for an entry in _zonerefs * zonelist_zone_idx() - Return the index of the zone for an entry * zonelist_node_idx() - Return the index of the node for an entry */ struct zonelist { struct zonelist_cache *zlcache_ptr; // NULL or &zlcache struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; #ifdef CONFIG_NUMA struct zonelist_cache zlcache; // optional ... #endif }; #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP struct node_active_region { unsigned long start_pfn; unsigned long end_pfn; int nid; }; #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */ #ifndef CONFIG_DISCONTIGMEM /* The array of struct pages - for discontigmem use pgdat->lmem_map */ extern struct page *mem_map; #endif /* * 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[MAX_ZONELISTS]; int nr_zones; #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ struct page *node_mem_map; #ifdef CONFIG_MEMCG struct page_cgroup *node_page_cgroup; #endif #endif #ifndef CONFIG_NO_BOOTMEM struct bootmem_data *bdata; #endif #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; nodemask_t reclaim_nodes; /* Nodes allowed to reclaim from */ wait_queue_head_t kswapd_wait; wait_queue_head_t pfmemalloc_wait; struct task_struct *kswapd; /* Protected by mem_hotplug_begin/end() */ int kswapd_max_order; enum zone_type classzone_idx; #ifdef CONFIG_NUMA_BALANCING /* Lock serializing the migrate rate limiting window */ spinlock_t numabalancing_migrate_lock; /* Rate limiting time interval */ unsigned long numabalancing_migrate_next_window; /* Number of pages migrated during the rate limiting time interval */ unsigned long numabalancing_migrate_nr_pages; #endif #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT /* * If memory initialisation on large machines is deferred then this * is the first PFN that needs to be initialised. */ RH_KABI_USE(1, unsigned long first_deferred_pfn) #else RH_KABI_RESERVE(1) #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ #ifdef CONFIG_ZONE_DEVICE RH_KABI_USE(2, struct zone *zone_device) #else RH_KABI_RESERVE(2) #endif /* reserved for Red Hat */ RH_KABI_RESERVE(3) RH_KABI_RESERVE(4) } 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)) #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) { return pgdat->node_start_pfn + pgdat->node_spanned_pages; } static inline bool pgdat_is_empty(pg_data_t *pgdat) { return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; } static inline int zone_id(const struct zone *zone) { struct pglist_data *pgdat = zone->zone_pgdat; #ifdef CONFIG_ZONE_DEVICE if (zone == pgdat->zone_device) return ZONE_DEVICE; #endif return zone - pgdat->node_zones; } #ifdef CONFIG_ZONE_DEVICE static inline bool is_dev_zone(const struct zone *zone) { return zone_id(zone) == ZONE_DEVICE; } #else static inline bool is_dev_zone(const struct zone *zone) { return false; } #endif #include <linux/memory_hotplug.h> extern struct mutex zonelists_mutex; void build_all_zonelists(pg_data_t *pgdat, struct zone *zone); void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx); bool zone_watermark_ok(struct zone *z, int order, unsigned long mark, int classzone_idx, int alloc_flags); bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark, int classzone_idx, int alloc_flags); enum memmap_context { MEMMAP_EARLY, MEMMAP_HOTPLUG, }; extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, unsigned long size, enum memmap_context context); extern void lruvec_init(struct lruvec *lruvec); static inline struct zone *lruvec_zone(struct lruvec *lruvec) { #ifdef CONFIG_MEMCG return lruvec->zone; #else return container_of(lruvec, struct zone, lruvec); #endif } #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_HAVE_MEMORYLESS_NODES int local_memory_node(int node_id); #else static inline int local_memory_node(int node_id) { return node_id; }; #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. */ #ifdef CONFIG_ZONE_DEVICE #define zone_idx(zone) (is_dev_zone(zone) ? ZONE_DEVICE : \ (zone) - (zone)->zone_pgdat->node_zones) #else #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) #endif static inline int populated_zone(struct zone *zone) { return (!!zone->present_pages); } extern int movable_zone; static inline int zone_movable_is_highmem(void) { #if defined(CONFIG_HIGHMEM) && defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) return movable_zone == ZONE_HIGHMEM; #else return 0; #endif } static inline int is_highmem_idx(enum zone_type idx) { #ifdef CONFIG_HIGHMEM return (idx == ZONE_HIGHMEM || (idx == ZONE_MOVABLE && zone_movable_is_highmem())); #else return 0; #endif } static inline int is_normal_idx(enum zone_type 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) { #ifdef CONFIG_HIGHMEM int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones; return zone_off == ZONE_HIGHMEM * sizeof(*zone) || (zone_off == ZONE_MOVABLE * sizeof(*zone) && zone_movable_is_highmem()); #else return 0; #endif } static inline int is_normal(struct zone *zone) { return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL; } static inline int is_dma32(struct zone *zone) { #ifdef CONFIG_ZONE_DMA32 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32; #else return 0; #endif } static inline int is_dma(struct zone *zone) { #ifdef CONFIG_ZONE_DMA return zone == zone->zone_pgdat->node_zones + ZONE_DMA; #else return 0; #endif } /* These two functions are used to setup the per zone pages min values */ struct ctl_table; int min_free_kbytes_sysctl_handler(struct ctl_table *, int, 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, void __user *, size_t *, loff_t *); int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); extern int numa_zonelist_order_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); extern char numa_zonelist_order[]; #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */ #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 #else /* CONFIG_NEED_MULTIPLE_NODES */ #include <asm/mmzone.h> #endif /* !CONFIG_NEED_MULTIPLE_NODES */ extern struct pglist_data *first_online_pgdat(void); extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); extern struct zone *next_zone(struct zone *zone); /** * for_each_online_pgdat - helper macro to iterate over all online nodes * @pgdat - pointer to a pg_data_t variable */ #define for_each_online_pgdat(pgdat) \ for (pgdat = first_online_pgdat(); \ pgdat; \ pgdat = next_online_pgdat(pgdat)) /** * 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. */ #define for_each_zone(zone) \ for (zone = (first_online_pgdat())->node_zones; \ zone; \ zone = next_zone(zone)) #define for_each_populated_zone(zone) \ for (zone = (first_online_pgdat())->node_zones; \ zone; \ zone = next_zone(zone)) \ if (!populated_zone(zone)) \ ; /* do nothing */ \ else static inline struct zone *zonelist_zone(struct zoneref *zoneref) { return zoneref->zone; } static inline int zonelist_zone_idx(struct zoneref *zoneref) { return zoneref->zone_idx; } static inline int zonelist_node_idx(struct zoneref *zoneref) { #ifdef CONFIG_NUMA /* zone_to_nid not available in this context */ return zoneref->zone->node; #else return 0; #endif /* CONFIG_NUMA */ } /** * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point * @z - The cursor used as a starting point for the search * @highest_zoneidx - The zone index of the highest zone to return * @nodes - An optional nodemask to filter the zonelist with * @zone - The first suitable zone found is returned via this parameter * * This function returns the next zone at or below a given zone index that is * within the allowed nodemask using a cursor as the starting point for the * search. The zoneref returned is a cursor that represents the current zone * being examined. It should be advanced by one before calling * next_zones_zonelist again. */ struct zoneref *next_zones_zonelist(struct zoneref *z, enum zone_type highest_zoneidx, nodemask_t *nodes, struct zone **zone); /** * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist * @zonelist - The zonelist to search for a suitable zone * @highest_zoneidx - The zone index of the highest zone to return * @nodes - An optional nodemask to filter the zonelist with * @zone - The first suitable zone found is returned via this parameter * * This function returns the first zone at or below a given zone index that is * within the allowed nodemask. The zoneref returned is a cursor that can be * used to iterate the zonelist with next_zones_zonelist by advancing it by * one before calling. */ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, enum zone_type highest_zoneidx, nodemask_t *nodes, struct zone **zone) { return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes, zone); } /** * for_each_zone_zonelist_nodemask - helper macro to iterate over valid zones in a zonelist at or below a given zone index and within a nodemask * @zone - The current zone in the iterator * @z - The current pointer within zonelist->zones being iterated * @zlist - The zonelist being iterated * @highidx - The zone index of the highest zone to return * @nodemask - Nodemask allowed by the allocator * * This iterator iterates though all zones at or below a given zone index and * within a given nodemask */ #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \ zone; \ z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \ /** * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index * @zone - The current zone in the iterator * @z - The current pointer within zonelist->zones being iterated * @zlist - The zonelist being iterated * @highidx - The zone index of the highest zone to return * * This iterator iterates though all zones at or below a given zone index. */ #define for_each_zone_zonelist(zone, z, zlist, highidx) \ for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) #ifdef CONFIG_SPARSEMEM #include <asm/sparsemem.h> #endif #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \ !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) static inline unsigned long early_pfn_to_nid(unsigned long pfn) { return 0; } #endif #ifdef CONFIG_FLATMEM #define pfn_to_nid(pfn) (0) #endif #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 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)) #define SECTION_BLOCKFLAGS_BITS \ ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS #error Allocator MAX_ORDER exceeds SECTION_SIZE #endif static inline unsigned long pfn_to_section_nr(unsigned long pfn) { return pfn >> PFN_SECTION_SHIFT; } static inline unsigned long section_nr_to_pfn(unsigned long sec) { return sec << PFN_SECTION_SHIFT; } #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) struct page; struct page_cgroup; 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()) * * Additionally during early boot we encode node id of * the location of the section here to guide allocation. * (see sparse.c::memory_present()) * * Making it a UL at least makes someone do a cast * before using it wrong. */ unsigned long section_mem_map; /* See declaration of similar field in struct zone */ unsigned long *pageblock_flags; #ifdef CONFIG_MEMCG /* * If !SPARSEMEM, pgdat doesn't have page_cgroup pointer. We use * section. (see memcontrol.h/page_cgroup.h about this.) */ struct page_cgroup *page_cgroup; unsigned long pad; #endif }; #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 DIV_ROUND_UP(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); extern unsigned long usemap_size(void); /* * 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)) #define SECTION_NID_SHIFT 2 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 present_section(struct mem_section *section) { return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); } static inline int present_section_nr(unsigned long nr) { return present_section(__nr_to_section(nr)); } static inline int valid_section(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)); } #ifndef CONFIG_HAVE_ARCH_PFN_VALID 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))); } #endif static inline int pfn_present(unsigned long pfn) { if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; return present_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(pfn) \ ({ \ unsigned long __pfn_to_nid_pfn = (pfn); \ page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ }) #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 */ /* * During memory init memblocks map pfns to nids. The search is expensive and * this caches recent lookups. The implementation of __early_pfn_to_nid * may treat start/end as pfns or sections. */ struct mminit_pfnnid_cache { unsigned long last_start; unsigned long last_end; int last_nid; }; #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); /* * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we * need to check pfn validility within that MAX_ORDER_NR_PAGES block. * pfn_valid_within() should be used in this case; we optimise this away * when we have no holes within a MAX_ORDER_NR_PAGES block. */ #ifdef CONFIG_HOLES_IN_ZONE #define pfn_valid_within(pfn) pfn_valid(pfn) #else #define pfn_valid_within(pfn) (1) #endif #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL /* * pfn_valid() is meant to be able to tell if a given PFN has valid memmap * associated with it or not. In FLATMEM, it is expected that holes always * have valid memmap as long as there is valid PFNs either side of the hole. * In SPARSEMEM, it is assumed that a valid section has a memmap for the * entire section. * * However, an ARM, and maybe other embedded architectures in the future * free memmap backing holes to save memory on the assumption the memmap is * never used. The page_zone linkages are then broken even though pfn_valid() * returns true. A walker of the full memmap must then do this additional * check to ensure the memmap they are looking at is sane by making sure * the zone and PFN linkages are still valid. This is expensive, but walkers * of the full memmap are extremely rare. */ int memmap_valid_within(unsigned long pfn, struct page *page, struct zone *zone); #else static inline int memmap_valid_within(unsigned long pfn, struct page *page, struct zone *zone) { return 1; } #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ #endif /* !__GENERATING_BOUNDS.H */ #endif /* !__ASSEMBLY__ */ #endif /* _LINUX_MMZONE_H */