#ifndef _LINUX_MMZONE_H
#define _LINUX_MMZONE_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <linux/config.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/cache.h>
#include <linux/threads.h>
#include <linux/numa.h>
#include <linux/init.h>
#include <asm/atomic.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
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;
#define ZONE_DMA 0
#define ZONE_NORMAL 1
#define ZONE_HIGHMEM 2
#define MAX_NR_ZONES 3 /* 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".
*/
#define GFP_ZONEMASK 0x03
/*
* As an optimisation any zone modifier bits which are only valid when
* no other zone modifier bits are set (loners) should be placed in
* the highest order bits of this field. This allows us to reduce the
* extent of the zonelists thus saving space. For example in the case
* of three zone modifier bits, we could require up to eight zonelists.
* If the left most zone modifier is a "loner" then the highest valid
* zonelist would be four allowing us to allocate only five zonelists.
* Use the first form when the left most bit is not a "loner", otherwise
* use the second.
*/
/* #define GFP_ZONETYPES (GFP_ZONEMASK + 1) */ /* Non-loner */
#define GFP_ZONETYPES ((GFP_ZONEMASK + 1) / 2 + 1) /* Loner */
/*
* On machines where it is needed (eg PCs) we divide physical memory
* into multiple physical zones. On a PC we have 3 zones:
*
* ZONE_DMA < 16 MB ISA DMA capable memory
* 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];
struct per_cpu_pageset pageset[NR_CPUS];
/*
* free areas of different sizes
*/
spinlock_t lock;
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 */
/*
* 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;
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;
struct page *node_mem_map;
struct bootmem_data *bdata;
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)
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 alloc_type, int can_try_harder, int gfp_high);
#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 <linux/topology.h>
/* Returns the number of the current Node. */
#define numa_node_id() (cpu_to_node(_smp_processor_id()))
#ifndef CONFIG_DISCONTIGMEM
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
#define pfn_to_nid(pfn) (0)
#else /* CONFIG_DISCONTIGMEM */
#include <asm/mmzone.h>
#if BITS_PER_LONG == 32 || defined(ARCH_HAS_ATOMIC_UNSIGNED)
/*
* with 32 bit page->flags field, we reserve 8 bits for node/zone info.
* there are 3 zones (2 bits) and this leaves 8-2=6 bits for nodes.
*/
#define MAX_NODES_SHIFT 6
#elif BITS_PER_LONG == 64
/*
* with 64 bit flags field, there's plenty of room.
*/
#define MAX_NODES_SHIFT 10
#endif
#endif /* !CONFIG_DISCONTIGMEM */
#if NODES_SHIFT > MAX_NODES_SHIFT
#error NODES_SHIFT > MAX_NODES_SHIFT
#endif
/* There are currently 3 zones: DMA, Normal & Highmem, thus we need 2 bits */
#define MAX_ZONES_SHIFT 2
#if ZONES_SHIFT > MAX_ZONES_SHIFT
#error ZONES_SHIFT > MAX_ZONES_SHIFT
#endif
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _LINUX_MMZONE_H */
