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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315/* SPDX-License-Identifier: GPL-2.0-or-later *//* * mm-internal API for the page (buddy) allocator. Public API lives in * include/linux/gfp.h. */#ifndef __MM_PAGE_ALLOC_H#define __MM_PAGE_ALLOC_H
#include <linux/mm.h>#include <linux/mmzone.h>#include <linux/nodemask.h>#include <linux/types.h>
#define ALLOC_DEFAULT 0/* The ALLOC_WMARK bits are used as an index to zone->watermark */#define ALLOC_WMARK_MIN WMARK_MIN#define ALLOC_WMARK_LOW WMARK_LOW#define ALLOC_WMARK_HIGH WMARK_HIGH#define ALLOC_NO_WATERMARKS 0x04 /* don't check watermarks at all */
/* Mask to get the watermark bits */#define ALLOC_WMARK_MASK (ALLOC_NO_WATERMARKS-1)
/* * Only MMU archs have async oom victim reclaim - aka oom_reaper so we * cannot assume a reduced access to memory reserves is sufficient for * !MMU */#ifdef CONFIG_MMU#define ALLOC_OOM 0x08#else#define ALLOC_OOM ALLOC_NO_WATERMARKS#endif
#define ALLOC_NON_BLOCK 0x10 /* Caller cannot block. Allow access * to 25% of the min watermark or * 62.5% if __GFP_HIGH is set. */#define ALLOC_MIN_RESERVE 0x20 /* __GFP_HIGH set. Allow access to 50% * of the min watermark. */#define ALLOC_CPUSET 0x40 /* check for correct cpuset */#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */#ifdef CONFIG_ZONE_DMA32#define ALLOC_NOFRAGMENT 0x100 /* avoid mixing pageblock types */#else#define ALLOC_NOFRAGMENT 0x0#endif#define ALLOC_HIGHATOMIC 0x200 /* Allows access to MIGRATE_HIGHATOMIC */#define ALLOC_NOLOCK 0x400 /* Only use spin_trylock in allocation path */#define ALLOC_KSWAPD 0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set *//* * Avoid alloc_tag recursion for internal allocations. * * Callers must clear_page_tag_ref() before freeing to avoid warnings from * alloc_tag_sub_check(). */#define ALLOC_NO_CODETAG 0x1000
/* Flags that allow allocations below the min watermark. */#define ALLOC_RESERVES (ALLOC_NON_BLOCK|ALLOC_MIN_RESERVE|ALLOC_HIGHATOMIC|ALLOC_OOM)
/* * Structure for holding the mostly immutable allocation parameters passed * between functions involved in allocations, including the alloc_pages* * family of functions. * * nodemask, migratetype and highest_zoneidx are initialized only once in * __alloc_pages() and then never change. * * zonelist, preferred_zone and highest_zoneidx are set first in * __alloc_pages() for the fast path, and might be later changed * in __alloc_pages_slowpath(). All other functions pass the whole structure * by a const pointer. */struct alloc_context { struct zonelist *zonelist; const nodemask_t *nodemask; struct zoneref *preferred_zoneref; int migratetype;
/* * highest_zoneidx represents highest usable zone index of * the allocation request. Due to the nature of the zone, * memory on lower zone than the highest_zoneidx will be * protected by lowmem_reserve[highest_zoneidx]. * * highest_zoneidx is also used by reclaim/compaction to limit * the target zone since higher zone than this index cannot be * usable for this allocation request. */ enum zone_type highest_zoneidx; bool spread_dirty_pages; /* Only flags that are global to the whole allocation go here. */ unsigned int alloc_flags; /* Set by __alloc_pages_slowpath() before reclaim and compaction */ unsigned int reclaim_compact_order;};
/* * This function returns the order of a free page in the buddy system. In * general, page_zone(page)->lock must be held by the caller to prevent the * page from being allocated in parallel and returning garbage as the order. * If a caller does not hold page_zone(page)->lock, it must guarantee that the * page cannot be allocated or merged in parallel. Alternatively, it must * handle invalid values gracefully, and use buddy_order_unsafe() below. */static inline unsigned int buddy_order(struct page *page){ /* PageBuddy() must be checked by the caller */ return page_private(page);}
/* * Like buddy_order(), but for callers who cannot afford to hold the zone lock. * PageBuddy() should be checked first by the caller to minimize race window, * and invalid values must be handled gracefully. * * READ_ONCE is used so that if the caller assigns the result into a local * variable and e.g. tests it for valid range before using, the compiler cannot * decide to remove the variable and inline the page_private(page) multiple * times, potentially observing different values in the tests and the actual * use of the result. */#define buddy_order_unsafe(page) READ_ONCE(page_private(page))
/* * This function checks whether a page is free && is the buddy * we can coalesce a page and its buddy if * (a) the buddy is not in a hole (check before calling!) && * (b) the buddy is in the buddy system && * (c) a page and its buddy have the same order && * (d) a page and its buddy are in the same zone. * * For recording whether a page is in the buddy system, we set PageBuddy. * Setting, clearing, and testing PageBuddy is serialized by zone->lock. * * For recording page's order, we use page_private(page). */static inline bool page_is_buddy(struct page *page, struct page *buddy, unsigned int order){ if (!page_is_guard(buddy) && !PageBuddy(buddy)) return false;
if (buddy_order(buddy) != order) return false;
/* * zone check is done late to avoid uselessly calculating * zone/node ids for pages that could never merge. */ if (page_zone_id(page) != page_zone_id(buddy)) return false;
VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
return true;}
/* * Locate the struct page for both the matching buddy in our * pair (buddy1) and the combined O(n+1) page they form (page). * * 1) Any buddy B1 will have an order O twin B2 which satisfies * the following equation: * B2 = B1 ^ (1 << O) * For example, if the starting buddy (buddy2) is #8 its order * 1 buddy is #10: * B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10 * * 2) Any buddy B will have an order O+1 parent P which * satisfies the following equation: * P = B & ~(1 << O) * * Assumption: *_mem_map is contiguous at least up to MAX_PAGE_ORDER */static inline unsigned long__find_buddy_pfn(unsigned long page_pfn, unsigned int order){ return page_pfn ^ (1 << order);}
/* * Find the buddy of @page and validate it. * @page: The input page * @pfn: The pfn of the page, it saves a call to page_to_pfn() when the * function is used in the performance-critical __free_one_page(). * @order: The order of the page * @buddy_pfn: The output pointer to the buddy pfn, it also saves a call to * page_to_pfn(). * * The found buddy can be a non PageBuddy, out of @page's zone, or its order is * not the same as @page. The validation is necessary before use it. * * Return: the found buddy page or NULL if not found. */static inline struct page *find_buddy_page_pfn(struct page *page, unsigned long pfn, unsigned int order, unsigned long *buddy_pfn){ unsigned long __buddy_pfn = __find_buddy_pfn(pfn, order); struct page *buddy;
buddy = page + (__buddy_pfn - pfn); if (buddy_pfn) *buddy_pfn = __buddy_pfn;
if (page_is_buddy(page, buddy, order)) return buddy; return NULL;}
extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn, unsigned long end_pfn, struct zone *zone);
static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn, unsigned long end_pfn, struct zone *zone){ if (zone_is_contiguous(zone)) return pfn_to_page(start_pfn);
return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);}
extern void __free_pages_core(struct page *page, unsigned int order, enum meminit_context context);
void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags, unsigned int alloc_flags);extern bool free_pages_prepare(struct page *page, unsigned int order);
extern int user_min_free_kbytes;
struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order, int nid, nodemask_t *nodemask, unsigned int alloc_flags);#define __alloc_frozen_pages(...) \ alloc_hooks(__alloc_frozen_pages_noprof(__VA_ARGS__))void free_frozen_pages(struct page *page, unsigned int order);void free_unref_folios(struct folio_batch *fbatch);
#ifdef CONFIG_NUMAstruct page *alloc_frozen_pages_noprof(gfp_t, unsigned int order);#elsestatic inline struct page *alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order){ return __alloc_frozen_pages_noprof(gfp, order, numa_node_id(), NULL, ALLOC_DEFAULT);}#endif
#define alloc_frozen_pages(...) \ alloc_hooks(alloc_frozen_pages_noprof(__VA_ARGS__))
struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned int order);#define alloc_frozen_pages_nolock(...) \ alloc_hooks(alloc_frozen_pages_nolock_noprof(__VA_ARGS__))void free_frozen_pages_nolock(struct page *page, unsigned int order);
struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order, int preferred_nid, nodemask_t *nodemask, unsigned int alloc_flags);#define __alloc_pages(...) alloc_hooks(__alloc_pages_noprof(__VA_ARGS__))
extern void zone_pcp_reset(struct zone *zone);extern void zone_pcp_disable(struct zone *zone);extern void zone_pcp_enable(struct zone *zone);extern void zone_pcp_init(struct zone *zone);
enum fallback_result { /* Found suitable migratetype, *mt_out is valid. */ FALLBACK_FOUND, /* No fallback found in requested order. */ FALLBACK_EMPTY, /* Passed @claimable, but claiming whole block is a bad idea. */ FALLBACK_NOCLAIM,};enum fallback_resultfind_suitable_fallback(struct free_area *area, unsigned int order, int migratetype, bool claimable, int *mt_out);
static inline bool free_area_empty(struct free_area *area, int migratetype){ return list_empty(&area->free_list[migratetype]);}
/* Convert GFP flags to their corresponding migrate type */#define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE)#define GFP_MOVABLE_SHIFT 3
static inline int gfp_migratetype(const gfp_t gfp_flags){ VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK); BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE); BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE); BUILD_BUG_ON((___GFP_RECLAIMABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_RECLAIMABLE); BUILD_BUG_ON(((___GFP_MOVABLE | ___GFP_RECLAIMABLE) >> GFP_MOVABLE_SHIFT) != MIGRATE_HIGHATOMIC);
if (unlikely(page_group_by_mobility_disabled)) return MIGRATE_UNMOVABLE;
/* Group based on mobility */ return (__force unsigned long)(gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT;}#undef GFP_MOVABLE_MASK#undef GFP_MOVABLE_SHIFT
bool decay_pcp_high(struct zone *zone, struct per_cpu_pages *pcp);void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);void drain_all_pages(struct zone *zone);
void page_alloc_init_cpuhp(void);void page_alloc_sysctl_init(void);
#endif /* __MM_PAGE_ALLOC_H */