fs: Allow fine-grained control of folio sizes (e6ebbdef) · Commits · EulixOS / Software / Kernel

include/linux/pagemap.h

+77 −13

Original line number	Diff line number	Diff line
		@@ -203,12 +203,21 @@ enum mapping_flags {
		AS_EXITING = 4, /* final truncate in progress */
		/* writeback related tags are not used */
		AS_NO_WRITEBACK_TAGS = 5,
		AS_LARGE_FOLIO_SUPPORT = 6,
		AS_RELEASE_ALWAYS, /* Call ->release_folio(), even if no private data */
		AS_STABLE_WRITES, /* must wait for writeback before modifying
		AS_RELEASE_ALWAYS = 6, /* Call ->release_folio(), even if no private data */
		AS_STABLE_WRITES = 7, /* must wait for writeback before modifying
		folio contents */
		AS_INACCESSIBLE = 8, /* Do not attempt direct R/W access to the mapping */
		/* Bits 16-25 are used for FOLIO_ORDER */
		AS_FOLIO_ORDER_BITS = 5,
		AS_FOLIO_ORDER_MIN = 16,
		AS_FOLIO_ORDER_MAX = AS_FOLIO_ORDER_MIN + AS_FOLIO_ORDER_BITS,
		};

		#define AS_FOLIO_ORDER_BITS_MASK ((1u << AS_FOLIO_ORDER_BITS) - 1)
		#define AS_FOLIO_ORDER_MIN_MASK (AS_FOLIO_ORDER_BITS_MASK << AS_FOLIO_ORDER_MIN)
		#define AS_FOLIO_ORDER_MAX_MASK (AS_FOLIO_ORDER_BITS_MASK << AS_FOLIO_ORDER_MAX)
		#define AS_FOLIO_ORDER_MASK (AS_FOLIO_ORDER_MIN_MASK \| AS_FOLIO_ORDER_MAX_MASK)

		/**
		* mapping_set_error - record a writeback error in the address_space
		* @mapping: the mapping in which an error should be set
		@@ -348,9 +357,51 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
		#define MAX_XAS_ORDER (XA_CHUNK_SHIFT * 2 - 1)
		#define MAX_PAGECACHE_ORDER min(MAX_XAS_ORDER, PREFERRED_MAX_PAGECACHE_ORDER)

		/*
		* mapping_set_folio_order_range() - Set the orders supported by a file.
		* @mapping: The address space of the file.
		* @min: Minimum folio order (between 0-MAX_PAGECACHE_ORDER inclusive).
		* @max: Maximum folio order (between @min-MAX_PAGECACHE_ORDER inclusive).
		*
		* The filesystem should call this function in its inode constructor to
		* indicate which base size (min) and maximum size (max) of folio the VFS
		* can use to cache the contents of the file. This should only be used
		* if the filesystem needs special handling of folio sizes (ie there is
		* something the core cannot know).
		* Do not tune it based on, eg, i_size.
		*
		* Context: This should not be called while the inode is active as it
		* is non-atomic.
		*/
		static inline void mapping_set_folio_order_range(struct address_space *mapping,
		unsigned int min,
		unsigned int max)
		{
		if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
		return;

		if (min > MAX_PAGECACHE_ORDER)
		min = MAX_PAGECACHE_ORDER;

		if (max > MAX_PAGECACHE_ORDER)
		max = MAX_PAGECACHE_ORDER;

		if (max < min)
		max = min;

		mapping->flags = (mapping->flags & ~AS_FOLIO_ORDER_MASK) \|
		(min << AS_FOLIO_ORDER_MIN) \| (max << AS_FOLIO_ORDER_MAX);
		}

		static inline void mapping_set_folio_min_order(struct address_space *mapping,
		unsigned int min)
		{
		mapping_set_folio_order_range(mapping, min, MAX_PAGECACHE_ORDER);
		}

		/**
		* mapping_set_large_folios() - Indicate the file supports large folios.
		* @mapping: The file.
		* @mapping: The address space of the file.
		*
		* The filesystem should call this function in its inode constructor to
		* indicate that the VFS can use large folios to cache the contents of
		@@ -361,7 +412,23 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
		*/
		static inline void mapping_set_large_folios(struct address_space *mapping)
		{
		__set_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
		mapping_set_folio_order_range(mapping, 0, MAX_PAGECACHE_ORDER);
		}

		static inline unsigned int
		mapping_max_folio_order(const struct address_space *mapping)
		{
		if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
		return 0;
		return (mapping->flags & AS_FOLIO_ORDER_MAX_MASK) >> AS_FOLIO_ORDER_MAX;
		}

		static inline unsigned int
		mapping_min_folio_order(const struct address_space *mapping)
		{
		if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
		return 0;
		return (mapping->flags & AS_FOLIO_ORDER_MIN_MASK) >> AS_FOLIO_ORDER_MIN;
		}

		/**
		@@ -375,7 +442,7 @@ static inline void mapping_set_large_folios(struct address_space *mapping)
		static inline void mapping_clear_large_folios(struct address_space *mapping)
		{
		WARN_ON_ONCE(!rwsem_is_locked(&mapping->invalidate_lock));
		__clear_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
		mapping_set_folio_order_range(mapping, 0, 0);
		}

		/*
		@@ -384,20 +451,17 @@ static inline void mapping_clear_large_folios(struct address_space *mapping)
		*/
		static inline bool mapping_large_folio_support(struct address_space *mapping)
		{
		/* AS_LARGE_FOLIO_SUPPORT is only reasonable for pagecache folios */
		/* AS_FOLIO_ORDER is only reasonable for pagecache folios */
		VM_WARN_ONCE((unsigned long)mapping & PAGE_MAPPING_ANON,
		"Anonymous mapping always supports large folio");

		return IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
		test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
		return mapping_max_folio_order(mapping) > 0;
		}

		/* Return the maximum folio size for this pagecache mapping, in bytes. */
		static inline size_t mapping_max_folio_size(struct address_space *mapping)
		static inline size_t mapping_max_folio_size(const struct address_space *mapping)
		{
		if (mapping_large_folio_support(mapping))
		return PAGE_SIZE << MAX_PAGECACHE_ORDER;
		return PAGE_SIZE;
		return PAGE_SIZE << mapping_max_folio_order(mapping);
		}

		static inline int filemap_nr_thps(struct address_space *mapping)

mm/readahead.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -513,10 +513,10 @@ void page_cache_ra_order(struct readahead_control *ractl,

		limit = min(limit, index + ra->size - 1);

		if (new_order < MAX_PAGECACHE_ORDER)
		if (new_order < mapping_max_folio_order(mapping))
		new_order += 2;

		new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order);
		new_order = min(mapping_max_folio_order(mapping), new_order);
		new_order = min_t(unsigned int, new_order, ilog2(ra->size));

		/* See comment in page_cache_ra_unbounded() */