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Diffstat (limited to 'kernel/include/linux/mmzone.h')
| -rw-r--r-- | kernel/include/linux/mmzone.h | 1272 |
1 files changed, 1272 insertions, 0 deletions
diff --git a/kernel/include/linux/mmzone.h b/kernel/include/linux/mmzone.h new file mode 100644 index 000000000..54d74f6eb --- /dev/null +++ b/kernel/include/linux/mmzone.h @@ -0,0 +1,1272 @@ +#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> + +/* 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) +#else +# define is_migrate_cma(migratetype) 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; + +#define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1) +#define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1) + +#define get_pageblock_migratetype(page) \ + get_pfnblock_flags_mask(page, page_to_pfn(page), \ + PB_migrate_end, MIGRATETYPE_MASK) + +static inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn) +{ + BUILD_BUG_ON(PB_migrate_end - PB_migrate != 2); + return get_pfnblock_flags_mask(page, pfn, PB_migrate_end, + MIGRATETYPE_MASK); +} + +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 */ + NR_PAGES_SCANNED, /* pages scanned since last reclaim */ +#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 clean file */ +#define ISOLATE_CLEAN ((__force isolate_mode_t)0x1) +/* 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, + __MAX_NR_ZONES +}; + +#ifndef __GENERATING_BOUNDS_H + +struct zone { + /* Read-mostly fields */ + + /* zone watermarks, access with *_wmark_pages(zone) macros */ + unsigned long watermark[NR_WMARK]; + + /* + * 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. + */ + long lowmem_reserve[MAX_NR_ZONES]; + +#ifdef CONFIG_NUMA + int node; +#endif + + /* + * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on + * this zone's LRU. Maintained by the pageout code. + */ + unsigned int inactive_ratio; + + struct pglist_data *zone_pgdat; + struct per_cpu_pageset __percpu *pageset; + + /* + * This is a per-zone reserve of pages that should not be + * considered dirtyable memory. + */ + unsigned long dirty_balance_reserve; + +#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_NUMA + /* + * zone reclaim becomes active if more unmapped pages exist. + */ + unsigned long min_unmapped_pages; + unsigned long min_slab_pages; +#endif /* CONFIG_NUMA */ + + /* 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 managed_pages; + unsigned long spanned_pages; + unsigned long present_pages; + + const char *name; + + /* + * Number of MIGRATE_RESERVE page block. To maintain for just + * optimization. Protected by zone->lock. + */ + int nr_migrate_reserve_block; + +#ifdef CONFIG_MEMORY_ISOLATION + /* + * Number of isolated pageblock. It is used to solve incorrect + * freepage counting problem due to racy retrieving migratetype + * of pageblock. Protected by zone->lock. + */ + unsigned long nr_isolate_pageblock; +#endif + +#ifdef CONFIG_MEMORY_HOTPLUG + /* see spanned/present_pages for more description */ + seqlock_t span_seqlock; +#endif + + /* + * 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; + + ZONE_PADDING(_pad1_) + /* free areas of different sizes */ + struct free_area free_area[MAX_ORDER]; + + /* zone flags, see below */ + unsigned long flags; + + /* Write-intensive fields used from the page allocator */ + spinlock_t lock; + + ZONE_PADDING(_pad2_) + + /* Write-intensive fields used by page reclaim */ + + /* 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; + + /* + * 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; + +#if defined CONFIG_COMPACTION || defined CONFIG_CMA + /* pfn where compaction free scanner should start */ + unsigned long compact_cached_free_pfn; + /* pfn where async and sync compaction migration scanner should start */ + unsigned long compact_cached_migrate_pfn[2]; +#endif + +#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 + +#if defined CONFIG_COMPACTION || defined CONFIG_CMA + /* Set to true when the PG_migrate_skip bits should be cleared */ + bool compact_blockskip_flush; +#endif + + ZONE_PADDING(_pad3_) + /* Zone statistics */ + atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; +} ____cacheline_internodealigned_in_smp; + +enum zone_flags { + 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_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_FAIR_DEPLETED, /* fair zone policy batch depleted */ +}; + +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_PAGE_EXTENSION + struct page_ext *node_page_ext; +#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. + * + * pgdat_resize_lock() and pgdat_resize_unlock() are provided to + * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG. + * + * Nests above zone->lock and zone->span_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; + 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 +} 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; +} + +#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, unsigned int order, + unsigned long mark, int classzone_idx, int alloc_flags); +bool zone_watermark_ok_safe(struct zone *z, unsigned 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. + */ +#define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) + +static inline int populated_zone(struct zone *zone) +{ + return (!!zone->present_pages); +} + +extern int movable_zone; + +#ifdef CONFIG_HIGHMEM +static inline int zone_movable_is_highmem(void) +{ +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP + return movable_zone == ZONE_HIGHMEM; +#else + return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; +#endif +} +#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 +} + +/** + * 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 +} + +/* 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 + * + * 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); + +/** + * 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) +{ + struct zoneref *z = next_zones_zonelist(zonelist->_zonerefs, + highest_zoneidx, nodes); + *zone = zonelist_zone(z); + return z; +} + +/** + * 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 = zonelist_zone(z)) \ + +/** + * 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 + +#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT) +#define section_nr_to_pfn(sec) ((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_ext; +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_PAGE_EXTENSION + /* + * If !SPARSEMEM, pgdat doesn't have page_ext pointer. We use + * section. (see page_ext.h about this.) + */ + struct page_ext *page_ext; + unsigned long pad; +#endif + /* + * WARNING: mem_section must be a power-of-2 in size for the + * calculation and use of SECTION_ROOT_MASK to make sense. + */ +}; + +#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 */ + +#ifdef CONFIG_NODES_SPAN_OTHER_NODES +bool early_pfn_in_nid(unsigned long pfn, int nid); +#else +#define early_pfn_in_nid(pfn, nid) (1) +#endif + +#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 */ |