include/linux/mmzone.h

20 #include <linux/page-flags-layout.h>
23 #include <linux/page-flags.h>
26 #include <asm/page.h>
58 	 * from MIGRATE_CMA pageblocks and page allocator never
80 	get_pfnblock_flags_mask(&folio->page, pfn, MIGRATETYPE_MASK))
111 #define get_pageblock_migratetype(page)					\
112 	get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK)
115 	get_pfnblock_flags_mask(&folio->page, folio_pfn(folio),		\
197 	NR_DIRTIED,		/* page dirtyings since bootup */
198 	NR_WRITTEN,		/* page writings since bootup */
337  * a page is on one of lrugen->folios[]. Otherwise it stores 0.
339  * A page is added to the youngest generation on faulting. The aging needs to
340  * check the accessed bit at least twice before handing this page over to the
342  * fault; the second check makes sure this page hasn't been used since then.
349  * PG_active is always cleared while a page is on one of lrugen->folios[] so
350  * that the aging needs not to worry about it. And it's set again when a page
356  * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits
363  * Each generation is divided into multiple tiers. A page accessed N times
364  * through file descriptors is in tier order_base_2(N). A page in the first tier
365  * (N=0,1) is marked by PG_referenced unless it was faulted in through page
366  * tables or read ahead. A page in any other tier (N>1) is marked by
678  * PCPF_PREV_FREE_HIGH_ORDER: a high-order page is freed in the
679  * previous page freeing.  To avoid to drain PCP for an accident
680  * high-order page freeing.
758 	 * 900MB. The kernel will set up special mappings (page
759 	 * table entries on i386) for each page that the kernel needs to
894 	 * by page allocator and vm scanner to calculate all kinds of watermarks
940 	/* Write-intensive fields used from the page allocator */
1100 static inline enum zone_type page_zonenum(const struct page *page)
1102 	ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
1103 	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
1108 	return page_zonenum(&folio->page);
1112 static inline bool is_zone_device_page(const struct page *page)
1114 	return page_zonenum(page) == ZONE_DEVICE;
1125 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1126 						     const struct page *b)
1138 static inline bool is_zone_device_page(const struct page *page)
1142 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
1143 						     const struct page *b)
1151 	return is_zone_device_page(&folio->page);
1154 static inline bool is_zone_movable_page(const struct page *page)
1156 	return page_zonenum(page) == ZONE_MOVABLE;
1235 extern struct page *mem_map;
1252 	 * Cases not accounted: memory outside kernel control, offline page,
1275  * Memory statistics and page replacement data structures are maintained on a
1295 	struct page *node_mem_map;
1304 	 * Also synchronizes pgdat->first_deferred_pfn during deferred page
1317 	unsigned long node_spanned_pages; /* total size of physical page
1359 	/* Write-intensive fields used by page reclaim */
1389 	/* Fields commonly accessed by the page reclaim scanner */
1800 struct page;
1873  *   1. All mem_map arrays are page-aligned.
1906 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1910 	return (struct page *)map;
1996  * @pfn: the page frame number to check
1998  * Check if there is a valid memory map entry aka struct page for the @pfn.
2000  * there is actual usable memory at that @pfn. The struct page may
2001  * represent a hole or an unusable page frame.