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mm/z3fold.c
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// SPDX-License-Identifier: GPL-2.0-only |
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/* * z3fold.c * * Author: Vitaly Wool <vitaly.wool@konsulko.com> * Copyright (C) 2016, Sony Mobile Communications Inc. * * This implementation is based on zbud written by Seth Jennings. * * z3fold is an special purpose allocator for storing compressed pages. It * can store up to three compressed pages per page which improves the * compression ratio of zbud while retaining its main concepts (e. g. always * storing an integral number of objects per page) and simplicity. * It still has simple and deterministic reclaim properties that make it * preferable to a higher density approach (with no requirement on integral * number of object per page) when reclaim is used. * * As in zbud, pages are divided into "chunks". The size of the chunks is * fixed at compile time and is determined by NCHUNKS_ORDER below. * * z3fold doesn't export any API and is meant to be used via zpool API. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/atomic.h> |
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#include <linux/sched.h> |
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#include <linux/cpumask.h> #include <linux/dcache.h> |
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#include <linux/list.h> #include <linux/mm.h> #include <linux/module.h> |
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#include <linux/page-flags.h> #include <linux/migrate.h> #include <linux/node.h> #include <linux/compaction.h> |
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#include <linux/percpu.h> |
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#include <linux/mount.h> #include <linux/fs.h> |
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#include <linux/preempt.h> |
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#include <linux/workqueue.h> |
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#include <linux/slab.h> #include <linux/spinlock.h> #include <linux/zpool.h> |
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/* * NCHUNKS_ORDER determines the internal allocation granularity, effectively * adjusting internal fragmentation. It also determines the number of * freelists maintained in each pool. NCHUNKS_ORDER of 6 means that the * allocation granularity will be in chunks of size PAGE_SIZE/64. Some chunks * in the beginning of an allocated page are occupied by z3fold header, so * NCHUNKS will be calculated to 63 (or 62 in case CONFIG_DEBUG_SPINLOCK=y), * which shows the max number of free chunks in z3fold page, also there will * be 63, or 62, respectively, freelists per pool. */ #define NCHUNKS_ORDER 6 #define CHUNK_SHIFT (PAGE_SHIFT - NCHUNKS_ORDER) #define CHUNK_SIZE (1 << CHUNK_SHIFT) #define ZHDR_SIZE_ALIGNED round_up(sizeof(struct z3fold_header), CHUNK_SIZE) #define ZHDR_CHUNKS (ZHDR_SIZE_ALIGNED >> CHUNK_SHIFT) #define TOTAL_CHUNKS (PAGE_SIZE >> CHUNK_SHIFT) #define NCHUNKS ((PAGE_SIZE - ZHDR_SIZE_ALIGNED) >> CHUNK_SHIFT) #define BUDDY_MASK (0x3) #define BUDDY_SHIFT 2 #define SLOTS_ALIGN (0x40) |
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/***************** * Structures *****************/ |
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struct z3fold_pool; struct z3fold_ops { int (*evict)(struct z3fold_pool *pool, unsigned long handle); }; enum buddy { HEADLESS = 0, FIRST, MIDDLE, LAST, |
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BUDDIES_MAX = LAST }; struct z3fold_buddy_slots { /* * we are using BUDDY_MASK in handle_to_buddy etc. so there should * be enough slots to hold all possible variants */ unsigned long slot[BUDDY_MASK + 1]; unsigned long pool; /* back link + flags */ |
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}; |
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#define HANDLE_FLAG_MASK (0x03) |
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/* |
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* struct z3fold_header - z3fold page metadata occupying first chunks of each |
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* z3fold page, except for HEADLESS pages |
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* @buddy: links the z3fold page into the relevant list in the * pool |
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* @page_lock: per-page lock |
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* @refcount: reference count for the z3fold page * @work: work_struct for page layout optimization |
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* @slots: pointer to the structure holding buddy slots |
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* @cpu: CPU which this page "belongs" to |
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* @first_chunks: the size of the first buddy in chunks, 0 if free * @middle_chunks: the size of the middle buddy in chunks, 0 if free * @last_chunks: the size of the last buddy in chunks, 0 if free * @first_num: the starting number (for the first handle) |
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* @mapped_count: the number of objects currently mapped |
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*/ struct z3fold_header { struct list_head buddy; |
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spinlock_t page_lock; |
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struct kref refcount; |
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struct work_struct work; |
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struct z3fold_buddy_slots *slots; |
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short cpu; |
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unsigned short first_chunks; unsigned short middle_chunks; unsigned short last_chunks; unsigned short start_middle; unsigned short first_num:2; |
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unsigned short mapped_count:2; |
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}; |
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/** * struct z3fold_pool - stores metadata for each z3fold pool |
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* @name: pool name * @lock: protects pool unbuddied/lru lists * @stale_lock: protects pool stale page list * @unbuddied: per-cpu array of lists tracking z3fold pages that contain 2- * buddies; the list each z3fold page is added to depends on * the size of its free region. |
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* @lru: list tracking the z3fold pages in LRU order by most recently * added buddy. |
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* @stale: list of pages marked for freeing |
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* @pages_nr: number of z3fold pages in the pool. |
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* @c_handle: cache for z3fold_buddy_slots allocation |
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* @ops: pointer to a structure of user defined operations specified at * pool creation time. |
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* @compact_wq: workqueue for page layout background optimization * @release_wq: workqueue for safe page release * @work: work_struct for safe page release |
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* @inode: inode for z3fold pseudo filesystem |
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* * This structure is allocated at pool creation time and maintains metadata * pertaining to a particular z3fold pool. */ struct z3fold_pool { |
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const char *name; |
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spinlock_t lock; |
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spinlock_t stale_lock; struct list_head *unbuddied; |
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struct list_head lru; |
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struct list_head stale; |
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atomic64_t pages_nr; |
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struct kmem_cache *c_handle; |
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const struct z3fold_ops *ops; struct zpool *zpool; const struct zpool_ops *zpool_ops; |
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struct workqueue_struct *compact_wq; struct workqueue_struct *release_wq; struct work_struct work; |
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struct inode *inode; |
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}; |
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/* * Internal z3fold page flags */ enum z3fold_page_flags { |
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PAGE_HEADLESS = 0, |
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MIDDLE_CHUNK_MAPPED, |
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NEEDS_COMPACTING, |
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PAGE_STALE, |
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PAGE_CLAIMED, /* by either reclaim or free */ |
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}; /***************** * Helpers *****************/ /* Converts an allocation size in bytes to size in z3fold chunks */ static int size_to_chunks(size_t size) { return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; } #define for_each_unbuddied_list(_iter, _begin) \ for ((_iter) = (_begin); (_iter) < NCHUNKS; (_iter)++) |
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static void compact_page_work(struct work_struct *w); |
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static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool) { struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle, GFP_KERNEL); if (slots) { memset(slots->slot, 0, sizeof(slots->slot)); slots->pool = (unsigned long)pool; } return slots; } static inline struct z3fold_pool *slots_to_pool(struct z3fold_buddy_slots *s) { return (struct z3fold_pool *)(s->pool & ~HANDLE_FLAG_MASK); } static inline struct z3fold_buddy_slots *handle_to_slots(unsigned long handle) { return (struct z3fold_buddy_slots *)(handle & ~(SLOTS_ALIGN - 1)); } static inline void free_handle(unsigned long handle) { struct z3fold_buddy_slots *slots; int i; bool is_free; if (handle & (1 << PAGE_HEADLESS)) return; WARN_ON(*(unsigned long *)handle == 0); *(unsigned long *)handle = 0; slots = handle_to_slots(handle); is_free = true; for (i = 0; i <= BUDDY_MASK; i++) { if (slots->slot[i]) { is_free = false; break; } } if (is_free) { struct z3fold_pool *pool = slots_to_pool(slots); kmem_cache_free(pool->c_handle, slots); } } |
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static struct dentry *z3fold_do_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { static const struct dentry_operations ops = { .d_dname = simple_dname, }; return mount_pseudo(fs_type, "z3fold:", NULL, &ops, 0x33); } static struct file_system_type z3fold_fs = { .name = "z3fold", .mount = z3fold_do_mount, .kill_sb = kill_anon_super, }; static struct vfsmount *z3fold_mnt; static int z3fold_mount(void) { int ret = 0; z3fold_mnt = kern_mount(&z3fold_fs); if (IS_ERR(z3fold_mnt)) ret = PTR_ERR(z3fold_mnt); return ret; } static void z3fold_unmount(void) { kern_unmount(z3fold_mnt); } static const struct address_space_operations z3fold_aops; static int z3fold_register_migration(struct z3fold_pool *pool) { pool->inode = alloc_anon_inode(z3fold_mnt->mnt_sb); if (IS_ERR(pool->inode)) { pool->inode = NULL; return 1; } pool->inode->i_mapping->private_data = pool; pool->inode->i_mapping->a_ops = &z3fold_aops; return 0; } static void z3fold_unregister_migration(struct z3fold_pool *pool) { if (pool->inode) iput(pool->inode); } |
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/* Initializes the z3fold header of a newly allocated z3fold page */ |
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static struct z3fold_header *init_z3fold_page(struct page *page, struct z3fold_pool *pool) |
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{ struct z3fold_header *zhdr = page_address(page); |
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struct z3fold_buddy_slots *slots = alloc_slots(pool); if (!slots) return NULL; |
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INIT_LIST_HEAD(&page->lru); |
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clear_bit(PAGE_HEADLESS, &page->private); clear_bit(MIDDLE_CHUNK_MAPPED, &page->private); |
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clear_bit(NEEDS_COMPACTING, &page->private); clear_bit(PAGE_STALE, &page->private); |
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clear_bit(PAGE_CLAIMED, &page->private); |
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|
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spin_lock_init(&zhdr->page_lock); |
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kref_init(&zhdr->refcount); |
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zhdr->first_chunks = 0; zhdr->middle_chunks = 0; zhdr->last_chunks = 0; zhdr->first_num = 0; zhdr->start_middle = 0; |
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zhdr->cpu = -1; |
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zhdr->slots = slots; |
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INIT_LIST_HEAD(&zhdr->buddy); |
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INIT_WORK(&zhdr->work, compact_page_work); |
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return zhdr; } /* Resets the struct page fields and frees the page */ |
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static void free_z3fold_page(struct page *page, bool headless) |
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{ |
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if (!headless) { lock_page(page); __ClearPageMovable(page); unlock_page(page); } ClearPagePrivate(page); |
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__free_page(page); } |
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/* Lock a z3fold page */ static inline void z3fold_page_lock(struct z3fold_header *zhdr) { spin_lock(&zhdr->page_lock); } |
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/* Try to lock a z3fold page */ static inline int z3fold_page_trylock(struct z3fold_header *zhdr) { return spin_trylock(&zhdr->page_lock); } |
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/* Unlock a z3fold page */ static inline void z3fold_page_unlock(struct z3fold_header *zhdr) { spin_unlock(&zhdr->page_lock); } |
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/* Helper function to build the index */ static inline int __idx(struct z3fold_header *zhdr, enum buddy bud) { return (bud + zhdr->first_num) & BUDDY_MASK; } |
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/* * Encodes the handle of a particular buddy within a z3fold page * Pool lock should be held as this function accesses first_num */ static unsigned long encode_handle(struct z3fold_header *zhdr, enum buddy bud) { |
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struct z3fold_buddy_slots *slots; unsigned long h = (unsigned long)zhdr; int idx = 0; |
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|
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/* * For a headless page, its handle is its pointer with the extra * PAGE_HEADLESS bit set */ if (bud == HEADLESS) return h | (1 << PAGE_HEADLESS); /* otherwise, return pointer to encoded handle */ idx = __idx(zhdr, bud); h += idx; if (bud == LAST) h |= (zhdr->last_chunks << BUDDY_SHIFT); slots = zhdr->slots; slots->slot[idx] = h; return (unsigned long)&slots->slot[idx]; |
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} /* Returns the z3fold page where a given handle is stored */ |
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static inline struct z3fold_header *handle_to_z3fold_header(unsigned long h) |
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{ |
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unsigned long addr = h; |
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if (!(addr & (1 << PAGE_HEADLESS))) |
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addr = *(unsigned long *)h; |
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return (struct z3fold_header *)(addr & PAGE_MASK); |
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} |
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/* only for LAST bud, returns zero otherwise */ static unsigned short handle_to_chunks(unsigned long handle) { |
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unsigned long addr = *(unsigned long *)handle; return (addr & ~PAGE_MASK) >> BUDDY_SHIFT; |
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} |
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/* * (handle & BUDDY_MASK) < zhdr->first_num is possible in encode_handle * but that doesn't matter. because the masking will result in the * correct buddy number. */ |
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static enum buddy handle_to_buddy(unsigned long handle) { |
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struct z3fold_header *zhdr; unsigned long addr; WARN_ON(handle & (1 << PAGE_HEADLESS)); addr = *(unsigned long *)handle; zhdr = (struct z3fold_header *)(addr & PAGE_MASK); return (addr - zhdr->first_num) & BUDDY_MASK; |
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} |
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static inline struct z3fold_pool *zhdr_to_pool(struct z3fold_header *zhdr) { |
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return slots_to_pool(zhdr->slots); |
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} |
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static void __release_z3fold_page(struct z3fold_header *zhdr, bool locked) { struct page *page = virt_to_page(zhdr); |
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struct z3fold_pool *pool = zhdr_to_pool(zhdr); |
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WARN_ON(!list_empty(&zhdr->buddy)); set_bit(PAGE_STALE, &page->private); |
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clear_bit(NEEDS_COMPACTING, &page->private); |
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spin_lock(&pool->lock); if (!list_empty(&page->lru)) |
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list_del_init(&page->lru); |
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spin_unlock(&pool->lock); if (locked) z3fold_page_unlock(zhdr); spin_lock(&pool->stale_lock); list_add(&zhdr->buddy, &pool->stale); queue_work(pool->release_wq, &pool->work); spin_unlock(&pool->stale_lock); } static void __attribute__((__unused__)) release_z3fold_page(struct kref *ref) { struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, refcount); __release_z3fold_page(zhdr, false); } static void release_z3fold_page_locked(struct kref *ref) { struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, refcount); WARN_ON(z3fold_page_trylock(zhdr)); __release_z3fold_page(zhdr, true); } static void release_z3fold_page_locked_list(struct kref *ref) { struct z3fold_header *zhdr = container_of(ref, struct z3fold_header, refcount); |
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struct z3fold_pool *pool = zhdr_to_pool(zhdr); spin_lock(&pool->lock); |
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list_del_init(&zhdr->buddy); |
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spin_unlock(&pool->lock); |
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WARN_ON(z3fold_page_trylock(zhdr)); __release_z3fold_page(zhdr, true); } static void free_pages_work(struct work_struct *w) { struct z3fold_pool *pool = container_of(w, struct z3fold_pool, work); spin_lock(&pool->stale_lock); while (!list_empty(&pool->stale)) { struct z3fold_header *zhdr = list_first_entry(&pool->stale, struct z3fold_header, buddy); struct page *page = virt_to_page(zhdr); list_del(&zhdr->buddy); if (WARN_ON(!test_bit(PAGE_STALE, &page->private))) continue; |
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spin_unlock(&pool->stale_lock); cancel_work_sync(&zhdr->work); |
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free_z3fold_page(page, false); |
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cond_resched(); spin_lock(&pool->stale_lock); } spin_unlock(&pool->stale_lock); } |
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/* * Returns the number of free chunks in a z3fold page. * NB: can't be used with HEADLESS pages. */ static int num_free_chunks(struct z3fold_header *zhdr) { int nfree; /* * If there is a middle object, pick up the bigger free space * either before or after it. Otherwise just subtract the number * of chunks occupied by the first and the last objects. */ if (zhdr->middle_chunks != 0) { int nfree_before = zhdr->first_chunks ? |
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0 : zhdr->start_middle - ZHDR_CHUNKS; |
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int nfree_after = zhdr->last_chunks ? |
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0 : TOTAL_CHUNKS - (zhdr->start_middle + zhdr->middle_chunks); |
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502 503 504 505 506 |
nfree = max(nfree_before, nfree_after); } else nfree = NCHUNKS - zhdr->first_chunks - zhdr->last_chunks; return nfree; } |
9050cce10 mm/z3fold.c: intr... |
507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 |
/* Add to the appropriate unbuddied list */ static inline void add_to_unbuddied(struct z3fold_pool *pool, struct z3fold_header *zhdr) { if (zhdr->first_chunks == 0 || zhdr->last_chunks == 0 || zhdr->middle_chunks == 0) { struct list_head *unbuddied = get_cpu_ptr(pool->unbuddied); int freechunks = num_free_chunks(zhdr); spin_lock(&pool->lock); list_add(&zhdr->buddy, &unbuddied[freechunks]); spin_unlock(&pool->lock); zhdr->cpu = smp_processor_id(); put_cpu_ptr(pool->unbuddied); } } |
ede93213a z3fold: fix heade... |
523 524 525 526 527 528 529 530 |
static inline void *mchunk_memmove(struct z3fold_header *zhdr, unsigned short dst_chunk) { void *beg = zhdr; return memmove(beg + (dst_chunk << CHUNK_SHIFT), beg + (zhdr->start_middle << CHUNK_SHIFT), zhdr->middle_chunks << CHUNK_SHIFT); } |
1b096e5ae z3fold: extend co... |
531 |
#define BIG_CHUNK_GAP 3 |
9a001fc19 z3fold: the 3-fol... |
532 533 534 535 |
/* Has to be called with lock held */ static int z3fold_compact_page(struct z3fold_header *zhdr) { struct page *page = virt_to_page(zhdr); |
9a001fc19 z3fold: the 3-fol... |
536 |
|
ede93213a z3fold: fix heade... |
537 538 |
if (test_bit(MIDDLE_CHUNK_MAPPED, &page->private)) return 0; /* can't move middle chunk, it's used */ |
9a001fc19 z3fold: the 3-fol... |
539 |
|
1f862989b mm/z3fold.c: supp... |
540 541 |
if (unlikely(PageIsolated(page))) return 0; |
ede93213a z3fold: fix heade... |
542 543 544 545 546 547 |
if (zhdr->middle_chunks == 0) return 0; /* nothing to compact */ if (zhdr->first_chunks == 0 && zhdr->last_chunks == 0) { /* move to the beginning */ mchunk_memmove(zhdr, ZHDR_CHUNKS); |
9a001fc19 z3fold: the 3-fol... |
548 549 550 551 |
zhdr->first_chunks = zhdr->middle_chunks; zhdr->middle_chunks = 0; zhdr->start_middle = 0; zhdr->first_num++; |
1b096e5ae z3fold: extend co... |
552 |
return 1; |
9a001fc19 z3fold: the 3-fol... |
553 |
} |
1b096e5ae z3fold: extend co... |
554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 |
/* * moving data is expensive, so let's only do that if * there's substantial gain (at least BIG_CHUNK_GAP chunks) */ if (zhdr->first_chunks != 0 && zhdr->last_chunks == 0 && zhdr->start_middle - (zhdr->first_chunks + ZHDR_CHUNKS) >= BIG_CHUNK_GAP) { mchunk_memmove(zhdr, zhdr->first_chunks + ZHDR_CHUNKS); zhdr->start_middle = zhdr->first_chunks + ZHDR_CHUNKS; return 1; } else if (zhdr->last_chunks != 0 && zhdr->first_chunks == 0 && TOTAL_CHUNKS - (zhdr->last_chunks + zhdr->start_middle + zhdr->middle_chunks) >= BIG_CHUNK_GAP) { unsigned short new_start = TOTAL_CHUNKS - zhdr->last_chunks - zhdr->middle_chunks; mchunk_memmove(zhdr, new_start); zhdr->start_middle = new_start; return 1; } return 0; |
9a001fc19 z3fold: the 3-fol... |
577 |
} |
d30561c56 z3fold: use per-c... |
578 579 |
static void do_compact_page(struct z3fold_header *zhdr, bool locked) { |
9050cce10 mm/z3fold.c: intr... |
580 |
struct z3fold_pool *pool = zhdr_to_pool(zhdr); |
d30561c56 z3fold: use per-c... |
581 |
struct page *page; |
d30561c56 z3fold: use per-c... |
582 583 584 585 586 587 |
page = virt_to_page(zhdr); if (locked) WARN_ON(z3fold_page_trylock(zhdr)); else z3fold_page_lock(zhdr); |
5d03a6613 mm/z3fold.c: use ... |
588 |
if (WARN_ON(!test_and_clear_bit(NEEDS_COMPACTING, &page->private))) { |
d30561c56 z3fold: use per-c... |
589 590 591 592 593 594 |
z3fold_page_unlock(zhdr); return; } spin_lock(&pool->lock); list_del_init(&zhdr->buddy); spin_unlock(&pool->lock); |
5d03a6613 mm/z3fold.c: use ... |
595 596 597 598 |
if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) { atomic64_dec(&pool->pages_nr); return; } |
1f862989b mm/z3fold.c: supp... |
599 600 601 602 603 |
if (unlikely(PageIsolated(page) || test_bit(PAGE_STALE, &page->private))) { z3fold_page_unlock(zhdr); return; } |
d30561c56 z3fold: use per-c... |
604 |
z3fold_compact_page(zhdr); |
9050cce10 mm/z3fold.c: intr... |
605 |
add_to_unbuddied(pool, zhdr); |
d30561c56 z3fold: use per-c... |
606 607 608 609 610 611 612 613 614 615 |
z3fold_page_unlock(zhdr); } static void compact_page_work(struct work_struct *w) { struct z3fold_header *zhdr = container_of(w, struct z3fold_header, work); do_compact_page(zhdr, false); } |
9050cce10 mm/z3fold.c: intr... |
616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 |
/* returns _locked_ z3fold page header or NULL */ static inline struct z3fold_header *__z3fold_alloc(struct z3fold_pool *pool, size_t size, bool can_sleep) { struct z3fold_header *zhdr = NULL; struct page *page; struct list_head *unbuddied; int chunks = size_to_chunks(size), i; lookup: /* First, try to find an unbuddied z3fold page. */ unbuddied = get_cpu_ptr(pool->unbuddied); for_each_unbuddied_list(i, chunks) { struct list_head *l = &unbuddied[i]; zhdr = list_first_entry_or_null(READ_ONCE(l), struct z3fold_header, buddy); if (!zhdr) continue; /* Re-check under lock. */ spin_lock(&pool->lock); l = &unbuddied[i]; if (unlikely(zhdr != list_first_entry(READ_ONCE(l), struct z3fold_header, buddy)) || !z3fold_page_trylock(zhdr)) { spin_unlock(&pool->lock); zhdr = NULL; put_cpu_ptr(pool->unbuddied); if (can_sleep) cond_resched(); goto lookup; } list_del_init(&zhdr->buddy); zhdr->cpu = -1; spin_unlock(&pool->lock); page = virt_to_page(zhdr); if (test_bit(NEEDS_COMPACTING, &page->private)) { z3fold_page_unlock(zhdr); zhdr = NULL; put_cpu_ptr(pool->unbuddied); if (can_sleep) cond_resched(); goto lookup; } /* * this page could not be removed from its unbuddied * list while pool lock was held, and then we've taken * page lock so kref_put could not be called before * we got here, so it's safe to just call kref_get() */ kref_get(&zhdr->refcount); break; } put_cpu_ptr(pool->unbuddied); |
351618b20 mm/z3fold.c: impr... |
674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 |
if (!zhdr) { int cpu; /* look for _exact_ match on other cpus' lists */ for_each_online_cpu(cpu) { struct list_head *l; unbuddied = per_cpu_ptr(pool->unbuddied, cpu); spin_lock(&pool->lock); l = &unbuddied[chunks]; zhdr = list_first_entry_or_null(READ_ONCE(l), struct z3fold_header, buddy); if (!zhdr || !z3fold_page_trylock(zhdr)) { spin_unlock(&pool->lock); zhdr = NULL; continue; } list_del_init(&zhdr->buddy); zhdr->cpu = -1; spin_unlock(&pool->lock); page = virt_to_page(zhdr); if (test_bit(NEEDS_COMPACTING, &page->private)) { z3fold_page_unlock(zhdr); zhdr = NULL; if (can_sleep) cond_resched(); continue; } kref_get(&zhdr->refcount); break; } } |
9050cce10 mm/z3fold.c: intr... |
709 710 |
return zhdr; } |
d30561c56 z3fold: use per-c... |
711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 |
/* * API Functions */ /** * z3fold_create_pool() - create a new z3fold pool * @name: pool name * @gfp: gfp flags when allocating the z3fold pool structure * @ops: user-defined operations for the z3fold pool * * Return: pointer to the new z3fold pool or NULL if the metadata allocation * failed. */ static struct z3fold_pool *z3fold_create_pool(const char *name, gfp_t gfp, const struct z3fold_ops *ops) { struct z3fold_pool *pool = NULL; int i, cpu; pool = kzalloc(sizeof(struct z3fold_pool), gfp); if (!pool) goto out; |
7c2b8baa6 mm/z3fold.c: add ... |
734 735 736 737 738 |
pool->c_handle = kmem_cache_create("z3fold_handle", sizeof(struct z3fold_buddy_slots), SLOTS_ALIGN, 0, NULL); if (!pool->c_handle) goto out_c; |
d30561c56 z3fold: use per-c... |
739 740 741 |
spin_lock_init(&pool->lock); spin_lock_init(&pool->stale_lock); pool->unbuddied = __alloc_percpu(sizeof(struct list_head)*NCHUNKS, 2); |
1ec6995d1 z3fold: fix memor... |
742 743 |
if (!pool->unbuddied) goto out_pool; |
d30561c56 z3fold: use per-c... |
744 745 746 747 748 749 750 751 752 753 754 755 |
for_each_possible_cpu(cpu) { struct list_head *unbuddied = per_cpu_ptr(pool->unbuddied, cpu); for_each_unbuddied_list(i, 0) INIT_LIST_HEAD(&unbuddied[i]); } INIT_LIST_HEAD(&pool->lru); INIT_LIST_HEAD(&pool->stale); atomic64_set(&pool->pages_nr, 0); pool->name = name; pool->compact_wq = create_singlethread_workqueue(pool->name); if (!pool->compact_wq) |
1ec6995d1 z3fold: fix memor... |
756 |
goto out_unbuddied; |
d30561c56 z3fold: use per-c... |
757 758 759 |
pool->release_wq = create_singlethread_workqueue(pool->name); if (!pool->release_wq) goto out_wq; |
1f862989b mm/z3fold.c: supp... |
760 761 |
if (z3fold_register_migration(pool)) goto out_rwq; |
d30561c56 z3fold: use per-c... |
762 763 764 |
INIT_WORK(&pool->work, free_pages_work); pool->ops = ops; return pool; |
1f862989b mm/z3fold.c: supp... |
765 766 |
out_rwq: destroy_workqueue(pool->release_wq); |
d30561c56 z3fold: use per-c... |
767 768 |
out_wq: destroy_workqueue(pool->compact_wq); |
1ec6995d1 z3fold: fix memor... |
769 770 771 |
out_unbuddied: free_percpu(pool->unbuddied); out_pool: |
7c2b8baa6 mm/z3fold.c: add ... |
772 773 |
kmem_cache_destroy(pool->c_handle); out_c: |
d30561c56 z3fold: use per-c... |
774 |
kfree(pool); |
1ec6995d1 z3fold: fix memor... |
775 |
out: |
d30561c56 z3fold: use per-c... |
776 777 778 779 780 781 782 783 784 785 786 |
return NULL; } /** * z3fold_destroy_pool() - destroys an existing z3fold pool * @pool: the z3fold pool to be destroyed * * The pool should be emptied before this function is called. */ static void z3fold_destroy_pool(struct z3fold_pool *pool) { |
7c2b8baa6 mm/z3fold.c: add ... |
787 |
kmem_cache_destroy(pool->c_handle); |
1f862989b mm/z3fold.c: supp... |
788 |
z3fold_unregister_migration(pool); |
d30561c56 z3fold: use per-c... |
789 790 791 792 |
destroy_workqueue(pool->release_wq); destroy_workqueue(pool->compact_wq); kfree(pool); } |
9a001fc19 z3fold: the 3-fol... |
793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 |
/** * z3fold_alloc() - allocates a region of a given size * @pool: z3fold pool from which to allocate * @size: size in bytes of the desired allocation * @gfp: gfp flags used if the pool needs to grow * @handle: handle of the new allocation * * This function will attempt to find a free region in the pool large enough to * satisfy the allocation request. A search of the unbuddied lists is * performed first. If no suitable free region is found, then a new page is * allocated and added to the pool to satisfy the request. * * gfp should not set __GFP_HIGHMEM as highmem pages cannot be used * as z3fold pool pages. * * Return: 0 if success and handle is set, otherwise -EINVAL if the size or * gfp arguments are invalid or -ENOMEM if the pool was unable to allocate * a new page. */ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp, unsigned long *handle) { |
9050cce10 mm/z3fold.c: intr... |
815 |
int chunks = size_to_chunks(size); |
9a001fc19 z3fold: the 3-fol... |
816 |
struct z3fold_header *zhdr = NULL; |
d30561c56 z3fold: use per-c... |
817 |
struct page *page = NULL; |
9a001fc19 z3fold: the 3-fol... |
818 |
enum buddy bud; |
8a97ea546 mm/z3fold.c: use ... |
819 |
bool can_sleep = gfpflags_allow_blocking(gfp); |
9a001fc19 z3fold: the 3-fol... |
820 821 822 823 824 825 826 827 828 829 |
if (!size || (gfp & __GFP_HIGHMEM)) return -EINVAL; if (size > PAGE_SIZE) return -ENOSPC; if (size > PAGE_SIZE - ZHDR_SIZE_ALIGNED - CHUNK_SIZE) bud = HEADLESS; else { |
9050cce10 mm/z3fold.c: intr... |
830 831 |
retry: zhdr = __z3fold_alloc(pool, size, can_sleep); |
d30561c56 z3fold: use per-c... |
832 |
if (zhdr) { |
2f1e5e4d8 z3fold: use per-p... |
833 834 835 |
if (zhdr->first_chunks == 0) { if (zhdr->middle_chunks != 0 && chunks >= zhdr->start_middle) |
9a001fc19 z3fold: the 3-fol... |
836 |
bud = LAST; |
2f1e5e4d8 z3fold: use per-p... |
837 838 839 840 841 842 843 |
else bud = FIRST; } else if (zhdr->last_chunks == 0) bud = LAST; else if (zhdr->middle_chunks == 0) bud = MIDDLE; else { |
5a27aa822 z3fold: add kref ... |
844 |
if (kref_put(&zhdr->refcount, |
d30561c56 z3fold: use per-c... |
845 |
release_z3fold_page_locked)) |
5a27aa822 z3fold: add kref ... |
846 |
atomic64_dec(&pool->pages_nr); |
d30561c56 z3fold: use per-c... |
847 848 |
else z3fold_page_unlock(zhdr); |
2f1e5e4d8 z3fold: use per-p... |
849 850 851 |
pr_err("No free chunks in unbuddied "); WARN_ON(1); |
9050cce10 mm/z3fold.c: intr... |
852 |
goto retry; |
9a001fc19 z3fold: the 3-fol... |
853 |
} |
9050cce10 mm/z3fold.c: intr... |
854 |
page = virt_to_page(zhdr); |
2f1e5e4d8 z3fold: use per-p... |
855 |
goto found; |
9a001fc19 z3fold: the 3-fol... |
856 857 |
} bud = FIRST; |
9a001fc19 z3fold: the 3-fol... |
858 |
} |
5c9bab592 z3fold: limit use... |
859 860 861 862 863 864 865 866 867 868 869 870 871 |
page = NULL; if (can_sleep) { spin_lock(&pool->stale_lock); zhdr = list_first_entry_or_null(&pool->stale, struct z3fold_header, buddy); /* * Before allocating a page, let's see if we can take one from * the stale pages list. cancel_work_sync() can sleep so we * limit this case to the contexts where we can sleep */ if (zhdr) { list_del(&zhdr->buddy); spin_unlock(&pool->stale_lock); |
d30561c56 z3fold: use per-c... |
872 |
cancel_work_sync(&zhdr->work); |
5c9bab592 z3fold: limit use... |
873 874 875 876 |
page = virt_to_page(zhdr); } else { spin_unlock(&pool->stale_lock); } |
d30561c56 z3fold: use per-c... |
877 |
} |
5c9bab592 z3fold: limit use... |
878 879 |
if (!page) page = alloc_page(gfp); |
d30561c56 z3fold: use per-c... |
880 |
|
9a001fc19 z3fold: the 3-fol... |
881 882 |
if (!page) return -ENOMEM; |
2f1e5e4d8 z3fold: use per-p... |
883 |
|
d30561c56 z3fold: use per-c... |
884 |
zhdr = init_z3fold_page(page, pool); |
9050cce10 mm/z3fold.c: intr... |
885 886 887 888 889 |
if (!zhdr) { __free_page(page); return -ENOMEM; } atomic64_inc(&pool->pages_nr); |
9a001fc19 z3fold: the 3-fol... |
890 891 892 893 894 |
if (bud == HEADLESS) { set_bit(PAGE_HEADLESS, &page->private); goto headless; } |
1f862989b mm/z3fold.c: supp... |
895 |
__SetPageMovable(page, pool->inode->i_mapping); |
2f1e5e4d8 z3fold: use per-p... |
896 |
z3fold_page_lock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
897 898 899 900 901 902 903 904 |
found: if (bud == FIRST) zhdr->first_chunks = chunks; else if (bud == LAST) zhdr->last_chunks = chunks; else { zhdr->middle_chunks = chunks; |
ede93213a z3fold: fix heade... |
905 |
zhdr->start_middle = zhdr->first_chunks + ZHDR_CHUNKS; |
9a001fc19 z3fold: the 3-fol... |
906 |
} |
9050cce10 mm/z3fold.c: intr... |
907 |
add_to_unbuddied(pool, zhdr); |
9a001fc19 z3fold: the 3-fol... |
908 909 |
headless: |
d30561c56 z3fold: use per-c... |
910 |
spin_lock(&pool->lock); |
9a001fc19 z3fold: the 3-fol... |
911 912 913 914 915 916 917 918 |
/* Add/move z3fold page to beginning of LRU */ if (!list_empty(&page->lru)) list_del(&page->lru); list_add(&page->lru, &pool->lru); *handle = encode_handle(zhdr, bud); spin_unlock(&pool->lock); |
2f1e5e4d8 z3fold: use per-p... |
919 920 |
if (bud != HEADLESS) z3fold_page_unlock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 |
return 0; } /** * z3fold_free() - frees the allocation associated with the given handle * @pool: pool in which the allocation resided * @handle: handle associated with the allocation returned by z3fold_alloc() * * In the case that the z3fold page in which the allocation resides is under * reclaim, as indicated by the PG_reclaim flag being set, this function * only sets the first|last_chunks to 0. The page is actually freed * once both buddies are evicted (see z3fold_reclaim_page() below). */ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) { struct z3fold_header *zhdr; |
9a001fc19 z3fold: the 3-fol... |
938 939 |
struct page *page; enum buddy bud; |
9a001fc19 z3fold: the 3-fol... |
940 941 942 943 |
zhdr = handle_to_z3fold_header(handle); page = virt_to_page(zhdr); if (test_bit(PAGE_HEADLESS, &page->private)) { |
ca0246bb9 z3fold: fix possi... |
944 945 946 947 948 949 950 951 952 |
/* if a headless page is under reclaim, just leave. * NB: we use test_and_set_bit for a reason: if the bit * has not been set before, we release this page * immediately so we don't care about its value any more. */ if (!test_and_set_bit(PAGE_CLAIMED, &page->private)) { spin_lock(&pool->lock); list_del(&page->lru); spin_unlock(&pool->lock); |
1f862989b mm/z3fold.c: supp... |
953 |
free_z3fold_page(page, true); |
ca0246bb9 z3fold: fix possi... |
954 |
atomic64_dec(&pool->pages_nr); |
9a001fc19 z3fold: the 3-fol... |
955 |
} |
ca0246bb9 z3fold: fix possi... |
956 |
return; |
9a001fc19 z3fold: the 3-fol... |
957 |
} |
ca0246bb9 z3fold: fix possi... |
958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 |
/* Non-headless case */ z3fold_page_lock(zhdr); bud = handle_to_buddy(handle); switch (bud) { case FIRST: zhdr->first_chunks = 0; break; case MIDDLE: zhdr->middle_chunks = 0; break; case LAST: zhdr->last_chunks = 0; break; default: pr_err("%s: unknown bud %d ", __func__, bud); WARN_ON(1); z3fold_page_unlock(zhdr); |
d30561c56 z3fold: use per-c... |
977 978 |
return; } |
7c2b8baa6 mm/z3fold.c: add ... |
979 |
free_handle(handle); |
d30561c56 z3fold: use per-c... |
980 981 982 983 |
if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) { atomic64_dec(&pool->pages_nr); return; } |
ca0246bb9 z3fold: fix possi... |
984 |
if (test_bit(PAGE_CLAIMED, &page->private)) { |
6098d7e13 z3fold: fix recla... |
985 986 987 |
z3fold_page_unlock(zhdr); return; } |
1f862989b mm/z3fold.c: supp... |
988 989 |
if (unlikely(PageIsolated(page)) || test_and_set_bit(NEEDS_COMPACTING, &page->private)) { |
5a27aa822 z3fold: add kref ... |
990 |
z3fold_page_unlock(zhdr); |
d30561c56 z3fold: use per-c... |
991 992 993 |
return; } if (zhdr->cpu < 0 || !cpu_online(zhdr->cpu)) { |
2f1e5e4d8 z3fold: use per-p... |
994 |
spin_lock(&pool->lock); |
d30561c56 z3fold: use per-c... |
995 |
list_del_init(&zhdr->buddy); |
2f1e5e4d8 z3fold: use per-p... |
996 |
spin_unlock(&pool->lock); |
d30561c56 z3fold: use per-c... |
997 |
zhdr->cpu = -1; |
5d03a6613 mm/z3fold.c: use ... |
998 |
kref_get(&zhdr->refcount); |
d30561c56 z3fold: use per-c... |
999 1000 |
do_compact_page(zhdr, true); return; |
9a001fc19 z3fold: the 3-fol... |
1001 |
} |
5d03a6613 mm/z3fold.c: use ... |
1002 |
kref_get(&zhdr->refcount); |
d30561c56 z3fold: use per-c... |
1003 1004 |
queue_work_on(zhdr->cpu, pool->compact_wq, &zhdr->work); z3fold_page_unlock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
1005 1006 1007 1008 1009 |
} /** * z3fold_reclaim_page() - evicts allocations from a pool page and frees it * @pool: pool from which a page will attempt to be evicted |
f144c390f mm: docs: fix par... |
1010 |
* @retries: number of pages on the LRU list for which eviction will |
9a001fc19 z3fold: the 3-fol... |
1011 1012 1013 1014 1015 1016 1017 1018 1019 |
* be attempted before failing * * z3fold reclaim is different from normal system reclaim in that it is done * from the bottom, up. This is because only the bottom layer, z3fold, has * information on how the allocations are organized within each z3fold page. * This has the potential to create interesting locking situations between * z3fold and the user, however. * * To avoid these, this is how z3fold_reclaim_page() should be called: |
f144c390f mm: docs: fix par... |
1020 |
* |
9a001fc19 z3fold: the 3-fol... |
1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 |
* The user detects a page should be reclaimed and calls z3fold_reclaim_page(). * z3fold_reclaim_page() will remove a z3fold page from the pool LRU list and * call the user-defined eviction handler with the pool and handle as * arguments. * * If the handle can not be evicted, the eviction handler should return * non-zero. z3fold_reclaim_page() will add the z3fold page back to the * appropriate list and try the next z3fold page on the LRU up to * a user defined number of retries. * * If the handle is successfully evicted, the eviction handler should * return 0 _and_ should have called z3fold_free() on the handle. z3fold_free() * contains logic to delay freeing the page if the page is under reclaim, * as indicated by the setting of the PG_reclaim flag on the underlying page. * * If all buddies in the z3fold page are successfully evicted, then the * z3fold page can be freed. * * Returns: 0 if page is successfully freed, otherwise -EINVAL if there are * no pages to evict or an eviction handler is not registered, -EAGAIN if * the retry limit was hit. */ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) { |
d30561c56 z3fold: use per-c... |
1045 1046 1047 1048 |
int i, ret = 0; struct z3fold_header *zhdr = NULL; struct page *page = NULL; struct list_head *pos; |
9a001fc19 z3fold: the 3-fol... |
1049 1050 1051 |
unsigned long first_handle = 0, middle_handle = 0, last_handle = 0; spin_lock(&pool->lock); |
2f1e5e4d8 z3fold: use per-p... |
1052 |
if (!pool->ops || !pool->ops->evict || retries == 0) { |
9a001fc19 z3fold: the 3-fol... |
1053 1054 1055 1056 |
spin_unlock(&pool->lock); return -EINVAL; } for (i = 0; i < retries; i++) { |
2f1e5e4d8 z3fold: use per-p... |
1057 1058 1059 1060 |
if (list_empty(&pool->lru)) { spin_unlock(&pool->lock); return -EINVAL; } |
d30561c56 z3fold: use per-c... |
1061 1062 |
list_for_each_prev(pos, &pool->lru) { page = list_entry(pos, struct page, lru); |
ca0246bb9 z3fold: fix possi... |
1063 1064 1065 1066 1067 1068 |
/* this bit could have been set by free, in which case * we pass over to the next page in the pool. */ if (test_and_set_bit(PAGE_CLAIMED, &page->private)) continue; |
1f862989b mm/z3fold.c: supp... |
1069 1070 |
if (unlikely(PageIsolated(page))) continue; |
d30561c56 z3fold: use per-c... |
1071 |
if (test_bit(PAGE_HEADLESS, &page->private)) |
d30561c56 z3fold: use per-c... |
1072 |
break; |
1f862989b mm/z3fold.c: supp... |
1073 |
zhdr = page_address(page); |
ca0246bb9 z3fold: fix possi... |
1074 1075 |
if (!z3fold_page_trylock(zhdr)) { zhdr = NULL; |
d30561c56 z3fold: use per-c... |
1076 |
continue; /* can't evict at this point */ |
ca0246bb9 z3fold: fix possi... |
1077 |
} |
d30561c56 z3fold: use per-c... |
1078 1079 1080 |
kref_get(&zhdr->refcount); list_del_init(&zhdr->buddy); zhdr->cpu = -1; |
6098d7e13 z3fold: fix recla... |
1081 |
break; |
d30561c56 z3fold: use per-c... |
1082 |
} |
ca0246bb9 z3fold: fix possi... |
1083 1084 |
if (!zhdr) break; |
5a27aa822 z3fold: add kref ... |
1085 |
list_del_init(&page->lru); |
d30561c56 z3fold: use per-c... |
1086 |
spin_unlock(&pool->lock); |
9a001fc19 z3fold: the 3-fol... |
1087 |
|
9a001fc19 z3fold: the 3-fol... |
1088 |
if (!test_bit(PAGE_HEADLESS, &page->private)) { |
9a001fc19 z3fold: the 3-fol... |
1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 |
/* * We need encode the handles before unlocking, since * we can race with free that will set * (first|last)_chunks to 0 */ first_handle = 0; last_handle = 0; middle_handle = 0; if (zhdr->first_chunks) first_handle = encode_handle(zhdr, FIRST); if (zhdr->middle_chunks) middle_handle = encode_handle(zhdr, MIDDLE); if (zhdr->last_chunks) last_handle = encode_handle(zhdr, LAST); |
d30561c56 z3fold: use per-c... |
1103 1104 1105 1106 |
/* * it's safe to unlock here because we hold a * reference to this page */ |
2f1e5e4d8 z3fold: use per-p... |
1107 |
z3fold_page_unlock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
1108 1109 1110 1111 |
} else { first_handle = encode_handle(zhdr, HEADLESS); last_handle = middle_handle = 0; } |
9a001fc19 z3fold: the 3-fol... |
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 |
/* Issue the eviction callback(s) */ if (middle_handle) { ret = pool->ops->evict(pool, middle_handle); if (ret) goto next; } if (first_handle) { ret = pool->ops->evict(pool, first_handle); if (ret) goto next; } if (last_handle) { ret = pool->ops->evict(pool, last_handle); if (ret) goto next; } next: |
5a27aa822 z3fold: add kref ... |
1129 1130 |
if (test_bit(PAGE_HEADLESS, &page->private)) { if (ret == 0) { |
1f862989b mm/z3fold.c: supp... |
1131 |
free_z3fold_page(page, true); |
ca0246bb9 z3fold: fix possi... |
1132 |
atomic64_dec(&pool->pages_nr); |
5a27aa822 z3fold: add kref ... |
1133 |
return 0; |
5a27aa822 z3fold: add kref ... |
1134 |
} |
6098d7e13 z3fold: fix recla... |
1135 1136 1137 1138 1139 |
spin_lock(&pool->lock); list_add(&page->lru, &pool->lru); spin_unlock(&pool->lock); } else { z3fold_page_lock(zhdr); |
ca0246bb9 z3fold: fix possi... |
1140 |
clear_bit(PAGE_CLAIMED, &page->private); |
6098d7e13 z3fold: fix recla... |
1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 |
if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) { atomic64_dec(&pool->pages_nr); return 0; } /* * if we are here, the page is still not completely * free. Take the global pool lock then to be able * to add it back to the lru list */ spin_lock(&pool->lock); list_add(&page->lru, &pool->lru); |
d5567c9df z3fold: fix poten... |
1153 |
spin_unlock(&pool->lock); |
6098d7e13 z3fold: fix recla... |
1154 |
z3fold_page_unlock(zhdr); |
5a27aa822 z3fold: add kref ... |
1155 |
} |
2f1e5e4d8 z3fold: use per-p... |
1156 |
|
6098d7e13 z3fold: fix recla... |
1157 1158 |
/* We started off locked to we need to lock the pool back */ spin_lock(&pool->lock); |
9a001fc19 z3fold: the 3-fol... |
1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 |
} spin_unlock(&pool->lock); return -EAGAIN; } /** * z3fold_map() - maps the allocation associated with the given handle * @pool: pool in which the allocation resides * @handle: handle associated with the allocation to be mapped * * Extracts the buddy number from handle and constructs the pointer to the * correct starting chunk within the page. * * Returns: a pointer to the mapped allocation */ static void *z3fold_map(struct z3fold_pool *pool, unsigned long handle) { struct z3fold_header *zhdr; struct page *page; void *addr; enum buddy buddy; |
9a001fc19 z3fold: the 3-fol... |
1180 1181 1182 1183 1184 1185 |
zhdr = handle_to_z3fold_header(handle); addr = zhdr; page = virt_to_page(zhdr); if (test_bit(PAGE_HEADLESS, &page->private)) goto out; |
2f1e5e4d8 z3fold: use per-p... |
1186 |
z3fold_page_lock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 |
buddy = handle_to_buddy(handle); switch (buddy) { case FIRST: addr += ZHDR_SIZE_ALIGNED; break; case MIDDLE: addr += zhdr->start_middle << CHUNK_SHIFT; set_bit(MIDDLE_CHUNK_MAPPED, &page->private); break; case LAST: |
ca0246bb9 z3fold: fix possi... |
1197 |
addr += PAGE_SIZE - (handle_to_chunks(handle) << CHUNK_SHIFT); |
9a001fc19 z3fold: the 3-fol... |
1198 1199 1200 1201 1202 1203 1204 1205 |
break; default: pr_err("unknown buddy id %d ", buddy); WARN_ON(1); addr = NULL; break; } |
2f1e5e4d8 z3fold: use per-p... |
1206 |
|
1f862989b mm/z3fold.c: supp... |
1207 1208 |
if (addr) zhdr->mapped_count++; |
2f1e5e4d8 z3fold: use per-p... |
1209 |
z3fold_page_unlock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
1210 |
out: |
9a001fc19 z3fold: the 3-fol... |
1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 |
return addr; } /** * z3fold_unmap() - unmaps the allocation associated with the given handle * @pool: pool in which the allocation resides * @handle: handle associated with the allocation to be unmapped */ static void z3fold_unmap(struct z3fold_pool *pool, unsigned long handle) { struct z3fold_header *zhdr; struct page *page; enum buddy buddy; |
9a001fc19 z3fold: the 3-fol... |
1224 1225 |
zhdr = handle_to_z3fold_header(handle); page = virt_to_page(zhdr); |
2f1e5e4d8 z3fold: use per-p... |
1226 |
if (test_bit(PAGE_HEADLESS, &page->private)) |
9a001fc19 z3fold: the 3-fol... |
1227 |
return; |
9a001fc19 z3fold: the 3-fol... |
1228 |
|
2f1e5e4d8 z3fold: use per-p... |
1229 |
z3fold_page_lock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
1230 1231 1232 |
buddy = handle_to_buddy(handle); if (buddy == MIDDLE) clear_bit(MIDDLE_CHUNK_MAPPED, &page->private); |
1f862989b mm/z3fold.c: supp... |
1233 |
zhdr->mapped_count--; |
2f1e5e4d8 z3fold: use per-p... |
1234 |
z3fold_page_unlock(zhdr); |
9a001fc19 z3fold: the 3-fol... |
1235 1236 1237 1238 1239 1240 |
} /** * z3fold_get_pool_size() - gets the z3fold pool size in pages * @pool: pool whose size is being queried * |
12d59ae67 z3fold: make page... |
1241 |
* Returns: size in pages of the given pool. |
9a001fc19 z3fold: the 3-fol... |
1242 1243 1244 |
*/ static u64 z3fold_get_pool_size(struct z3fold_pool *pool) { |
12d59ae67 z3fold: make page... |
1245 |
return atomic64_read(&pool->pages_nr); |
9a001fc19 z3fold: the 3-fol... |
1246 |
} |
1f862989b mm/z3fold.c: supp... |
1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 |
static bool z3fold_page_isolate(struct page *page, isolate_mode_t mode) { struct z3fold_header *zhdr; struct z3fold_pool *pool; VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(PageIsolated(page), page); if (test_bit(PAGE_HEADLESS, &page->private)) return false; zhdr = page_address(page); z3fold_page_lock(zhdr); if (test_bit(NEEDS_COMPACTING, &page->private) || test_bit(PAGE_STALE, &page->private)) goto out; pool = zhdr_to_pool(zhdr); if (zhdr->mapped_count == 0) { kref_get(&zhdr->refcount); if (!list_empty(&zhdr->buddy)) list_del_init(&zhdr->buddy); spin_lock(&pool->lock); if (!list_empty(&page->lru)) list_del(&page->lru); spin_unlock(&pool->lock); z3fold_page_unlock(zhdr); return true; } out: z3fold_page_unlock(zhdr); return false; } static int z3fold_page_migrate(struct address_space *mapping, struct page *newpage, struct page *page, enum migrate_mode mode) { struct z3fold_header *zhdr, *new_zhdr; struct z3fold_pool *pool; struct address_space *new_mapping; VM_BUG_ON_PAGE(!PageMovable(page), page); VM_BUG_ON_PAGE(!PageIsolated(page), page); zhdr = page_address(page); pool = zhdr_to_pool(zhdr); if (!trylock_page(page)) return -EAGAIN; if (!z3fold_page_trylock(zhdr)) { unlock_page(page); return -EAGAIN; } if (zhdr->mapped_count != 0) { z3fold_page_unlock(zhdr); unlock_page(page); return -EBUSY; } new_zhdr = page_address(newpage); memcpy(new_zhdr, zhdr, PAGE_SIZE); newpage->private = page->private; page->private = 0; z3fold_page_unlock(zhdr); spin_lock_init(&new_zhdr->page_lock); new_mapping = page_mapping(page); __ClearPageMovable(page); ClearPagePrivate(page); get_page(newpage); z3fold_page_lock(new_zhdr); if (new_zhdr->first_chunks) encode_handle(new_zhdr, FIRST); if (new_zhdr->last_chunks) encode_handle(new_zhdr, LAST); if (new_zhdr->middle_chunks) encode_handle(new_zhdr, MIDDLE); set_bit(NEEDS_COMPACTING, &newpage->private); new_zhdr->cpu = smp_processor_id(); spin_lock(&pool->lock); list_add(&newpage->lru, &pool->lru); spin_unlock(&pool->lock); __SetPageMovable(newpage, new_mapping); z3fold_page_unlock(new_zhdr); queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work); page_mapcount_reset(page); unlock_page(page); put_page(page); return 0; } static void z3fold_page_putback(struct page *page) { struct z3fold_header *zhdr; struct z3fold_pool *pool; zhdr = page_address(page); pool = zhdr_to_pool(zhdr); z3fold_page_lock(zhdr); if (!list_empty(&zhdr->buddy)) list_del_init(&zhdr->buddy); INIT_LIST_HEAD(&page->lru); if (kref_put(&zhdr->refcount, release_z3fold_page_locked)) { atomic64_dec(&pool->pages_nr); return; } spin_lock(&pool->lock); list_add(&page->lru, &pool->lru); spin_unlock(&pool->lock); z3fold_page_unlock(zhdr); } static const struct address_space_operations z3fold_aops = { .isolate_page = z3fold_page_isolate, .migratepage = z3fold_page_migrate, .putback_page = z3fold_page_putback, }; |
9a001fc19 z3fold: the 3-fol... |
1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 |
/***************** * zpool ****************/ static int z3fold_zpool_evict(struct z3fold_pool *pool, unsigned long handle) { if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict) return pool->zpool_ops->evict(pool->zpool, handle); else return -ENOENT; } static const struct z3fold_ops z3fold_zpool_ops = { .evict = z3fold_zpool_evict }; static void *z3fold_zpool_create(const char *name, gfp_t gfp, const struct zpool_ops *zpool_ops, struct zpool *zpool) { struct z3fold_pool *pool; |
d30561c56 z3fold: use per-c... |
1389 1390 |
pool = z3fold_create_pool(name, gfp, zpool_ops ? &z3fold_zpool_ops : NULL); |
9a001fc19 z3fold: the 3-fol... |
1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 |
if (pool) { pool->zpool = zpool; pool->zpool_ops = zpool_ops; } return pool; } static void z3fold_zpool_destroy(void *pool) { z3fold_destroy_pool(pool); } static int z3fold_zpool_malloc(void *pool, size_t size, gfp_t gfp, unsigned long *handle) { return z3fold_alloc(pool, size, gfp, handle); } static void z3fold_zpool_free(void *pool, unsigned long handle) { z3fold_free(pool, handle); } static int z3fold_zpool_shrink(void *pool, unsigned int pages, unsigned int *reclaimed) { unsigned int total = 0; int ret = -EINVAL; while (total < pages) { ret = z3fold_reclaim_page(pool, 8); if (ret < 0) break; total++; } if (reclaimed) *reclaimed = total; return ret; } static void *z3fold_zpool_map(void *pool, unsigned long handle, enum zpool_mapmode mm) { return z3fold_map(pool, handle); } static void z3fold_zpool_unmap(void *pool, unsigned long handle) { z3fold_unmap(pool, handle); } static u64 z3fold_zpool_total_size(void *pool) { return z3fold_get_pool_size(pool) * PAGE_SIZE; } static struct zpool_driver z3fold_zpool_driver = { .type = "z3fold", .owner = THIS_MODULE, .create = z3fold_zpool_create, .destroy = z3fold_zpool_destroy, .malloc = z3fold_zpool_malloc, .free = z3fold_zpool_free, .shrink = z3fold_zpool_shrink, .map = z3fold_zpool_map, .unmap = z3fold_zpool_unmap, .total_size = z3fold_zpool_total_size, }; MODULE_ALIAS("zpool-z3fold"); static int __init init_z3fold(void) { |
1f862989b mm/z3fold.c: supp... |
1464 |
int ret; |
ede93213a z3fold: fix heade... |
1465 1466 |
/* Make sure the z3fold header is not larger than the page size */ BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE); |
1f862989b mm/z3fold.c: supp... |
1467 1468 1469 |
ret = z3fold_mount(); if (ret) return ret; |
9a001fc19 z3fold: the 3-fol... |
1470 1471 1472 1473 1474 1475 1476 |
zpool_register_driver(&z3fold_zpool_driver); return 0; } static void __exit exit_z3fold(void) { |
1f862989b mm/z3fold.c: supp... |
1477 |
z3fold_unmount(); |
9a001fc19 z3fold: the 3-fol... |
1478 1479 1480 1481 1482 1483 1484 1485 1486 |
zpool_unregister_driver(&z3fold_zpool_driver); } module_init(init_z3fold); module_exit(exit_z3fold); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Vitaly Wool <vitalywool@gmail.com>"); MODULE_DESCRIPTION("3-Fold Allocator for Compressed Pages"); |