diff options
Diffstat (limited to 'mm/zsmalloc.c')
| -rw-r--r-- | mm/zsmalloc.c | 2158 |
1 files changed, 909 insertions, 1249 deletions
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 0787d33b80d8..5bf832f9c05c 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -1,3 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + /* * zsmalloc memory allocator * @@ -11,73 +13,48 @@ * Released under the terms of GNU General Public License Version 2.0 */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + /* - * Following is how we use various fields and flags of underlying - * struct page(s) to form a zspage. - * - * Usage of struct page fields: - * page->private: points to zspage - * page->freelist(index): links together all component pages of a zspage - * For the huge page, this is always 0, so we use this field - * to store handle. - * page->units: first object offset in a subpage of zspage - * - * Usage of struct page flags: - * PG_private: identifies the first component page - * PG_owner_priv_1: identifies the huge component page - * + * lock ordering: + * page_lock + * pool->lock + * class->lock + * zspage->lock */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - #include <linux/module.h> #include <linux/kernel.h> #include <linux/sched.h> -#include <linux/magic.h> -#include <linux/bitops.h> #include <linux/errno.h> #include <linux/highmem.h> #include <linux/string.h> #include <linux/slab.h> -#include <asm/tlbflush.h> -#include <asm/pgtable.h> -#include <linux/cpumask.h> -#include <linux/cpu.h> -#include <linux/vmalloc.h> -#include <linux/preempt.h> #include <linux/spinlock.h> +#include <linux/sprintf.h> #include <linux/shrinker.h> #include <linux/types.h> #include <linux/debugfs.h> #include <linux/zsmalloc.h> -#include <linux/zpool.h> -#include <linux/mount.h> -#include <linux/migrate.h> -#include <linux/pagemap.h> #include <linux/fs.h> +#include <linux/workqueue.h> +#include "zpdesc.h" #define ZSPAGE_MAGIC 0x58 /* - * This must be power of 2 and greater than of equal to sizeof(link_free). + * This must be power of 2 and greater than or equal to sizeof(link_free). * These two conditions ensure that any 'struct link_free' itself doesn't * span more than 1 page which avoids complex case of mapping 2 pages simply * to restore link_free pointer values. */ #define ZS_ALIGN 8 -/* - * A single 'zspage' is composed of up to 2^N discontiguous 0-order (single) - * pages. ZS_MAX_ZSPAGE_ORDER defines upper limit on N. - */ -#define ZS_MAX_ZSPAGE_ORDER 2 -#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(1, UL) << ZS_MAX_ZSPAGE_ORDER) - #define ZS_HANDLE_SIZE (sizeof(unsigned long)) /* * Object location (<PFN>, <obj_idx>) is encoded as - * as single (unsigned long) handle value. + * a single (unsigned long) handle value. * * Note that object index <obj_idx> starts from 0. * @@ -99,15 +76,6 @@ #define _PFN_BITS (MAX_POSSIBLE_PHYSMEM_BITS - PAGE_SHIFT) /* - * Memory for allocating for handle keeps object position by - * encoding <page, obj_idx> and the encoded value has a room - * in least bit(ie, look at obj_to_location). - * We use the bit to synchronize between object access by - * user and migration. - */ -#define HANDLE_PIN_BIT 0 - -/* * Head in allocated object should have OBJ_ALLOCATED_TAG * to identify the object was allocated or not. * It's okay to add the status bit in the least bit because @@ -115,16 +83,20 @@ * have room for two bit at least. */ #define OBJ_ALLOCATED_TAG 1 -#define OBJ_TAG_BITS 1 -#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS - OBJ_TAG_BITS) + +#define OBJ_TAG_BITS 1 +#define OBJ_TAG_MASK OBJ_ALLOCATED_TAG + +#define OBJ_INDEX_BITS (BITS_PER_LONG - _PFN_BITS) #define OBJ_INDEX_MASK ((_AC(1, UL) << OBJ_INDEX_BITS) - 1) -#define FULLNESS_BITS 2 +#define HUGE_BITS 1 +#define FULLNESS_BITS 4 #define CLASS_BITS 8 -#define ISOLATED_BITS 3 #define MAGIC_VAL_BITS 8 -#define MAX(a, b) ((a) >= (b) ? (a) : (b)) +#define ZS_MAX_PAGES_PER_ZSPAGE (_AC(CONFIG_ZSMALLOC_CHAIN_SIZE, UL)) + /* ZS_MIN_ALLOC_SIZE must be multiple of ZS_ALIGN */ #define ZS_MIN_ALLOC_SIZE \ MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS)) @@ -148,56 +120,45 @@ #define ZS_SIZE_CLASSES (DIV_ROUND_UP(ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE, \ ZS_SIZE_CLASS_DELTA) + 1) +/* + * Pages are distinguished by the ratio of used memory (that is the ratio + * of ->inuse objects to all objects that page can store). For example, + * INUSE_RATIO_10 means that the ratio of used objects is > 0% and <= 10%. + * + * The number of fullness groups is not random. It allows us to keep + * difference between the least busy page in the group (minimum permitted + * number of ->inuse objects) and the most busy page (maximum permitted + * number of ->inuse objects) at a reasonable value. + */ enum fullness_group { - ZS_EMPTY, - ZS_ALMOST_EMPTY, - ZS_ALMOST_FULL, - ZS_FULL, - NR_ZS_FULLNESS, + ZS_INUSE_RATIO_0, + ZS_INUSE_RATIO_10, + /* NOTE: 8 more fullness groups here */ + ZS_INUSE_RATIO_99 = 10, + ZS_INUSE_RATIO_100, + NR_FULLNESS_GROUPS, }; -enum zs_stat_type { - CLASS_EMPTY, - CLASS_ALMOST_EMPTY, - CLASS_ALMOST_FULL, - CLASS_FULL, - OBJ_ALLOCATED, - OBJ_USED, - NR_ZS_STAT_TYPE, +enum class_stat_type { + /* NOTE: stats for 12 fullness groups here: from inuse 0 to 100 */ + ZS_OBJS_ALLOCATED = NR_FULLNESS_GROUPS, + ZS_OBJS_INUSE, + NR_CLASS_STAT_TYPES, }; struct zs_size_stat { - unsigned long objs[NR_ZS_STAT_TYPE]; + unsigned long objs[NR_CLASS_STAT_TYPES]; }; #ifdef CONFIG_ZSMALLOC_STAT static struct dentry *zs_stat_root; #endif -#ifdef CONFIG_COMPACTION -static struct vfsmount *zsmalloc_mnt; -#endif - -/* - * We assign a page to ZS_ALMOST_EMPTY fullness group when: - * n <= N / f, where - * n = number of allocated objects - * N = total number of objects zspage can store - * f = fullness_threshold_frac - * - * Similarly, we assign zspage to: - * ZS_ALMOST_FULL when n > N / f - * ZS_EMPTY when n == 0 - * ZS_FULL when n == N - * - * (see: fix_fullness_group()) - */ -static const int fullness_threshold_frac = 4; static size_t huge_class_size; struct size_class { spinlock_t lock; - struct list_head fullness_list[NR_ZS_FULLNESS]; + struct list_head fullness_list[NR_FULLNESS_GROUPS]; /* * Size of objects stored in this class. Must be multiple * of ZS_ALIGN. @@ -211,22 +172,6 @@ struct size_class { struct zs_size_stat stats; }; -/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */ -static void SetPageHugeObject(struct page *page) -{ - SetPageOwnerPriv1(page); -} - -static void ClearPageHugeObject(struct page *page) -{ - ClearPageOwnerPriv1(page); -} - -static int PageHugeObject(struct page *page) -{ - return PageOwnerPriv1(page); -} - /* * Placed within free objects to form a singly linked list. * For every zspage, zspage->freeobj gives head of this list. @@ -259,60 +204,167 @@ struct zs_pool { struct zs_pool_stats stats; /* Compact classes */ - struct shrinker shrinker; + struct shrinker *shrinker; #ifdef CONFIG_ZSMALLOC_STAT struct dentry *stat_dentry; #endif #ifdef CONFIG_COMPACTION - struct inode *inode; struct work_struct free_work; #endif + /* protect zspage migration/compaction */ + rwlock_t lock; + atomic_t compaction_in_progress; +}; + +static inline void zpdesc_set_first(struct zpdesc *zpdesc) +{ + SetPagePrivate(zpdesc_page(zpdesc)); +} + +static inline void zpdesc_inc_zone_page_state(struct zpdesc *zpdesc) +{ + inc_zone_page_state(zpdesc_page(zpdesc), NR_ZSPAGES); +} + +static inline void zpdesc_dec_zone_page_state(struct zpdesc *zpdesc) +{ + dec_zone_page_state(zpdesc_page(zpdesc), NR_ZSPAGES); +} + +static inline struct zpdesc *alloc_zpdesc(gfp_t gfp, const int nid) +{ + struct page *page = alloc_pages_node(nid, gfp, 0); + + return page_zpdesc(page); +} + +static inline void free_zpdesc(struct zpdesc *zpdesc) +{ + struct page *page = zpdesc_page(zpdesc); + + /* PageZsmalloc is sticky until the page is freed to the buddy. */ + __free_page(page); +} + +#define ZS_PAGE_UNLOCKED 0 +#define ZS_PAGE_WRLOCKED -1 + +struct zspage_lock { + spinlock_t lock; + int cnt; + struct lockdep_map dep_map; }; struct zspage { struct { + unsigned int huge:HUGE_BITS; unsigned int fullness:FULLNESS_BITS; unsigned int class:CLASS_BITS + 1; - unsigned int isolated:ISOLATED_BITS; unsigned int magic:MAGIC_VAL_BITS; }; unsigned int inuse; unsigned int freeobj; - struct page *first_page; + struct zpdesc *first_zpdesc; struct list_head list; /* fullness list */ -#ifdef CONFIG_COMPACTION - rwlock_t lock; -#endif + struct zs_pool *pool; + struct zspage_lock zsl; }; -struct mapping_area { -#ifdef CONFIG_PGTABLE_MAPPING - struct vm_struct *vm; /* vm area for mapping object that span pages */ -#else - char *vm_buf; /* copy buffer for objects that span pages */ -#endif - char *vm_addr; /* address of kmap_atomic()'ed pages */ - enum zs_mapmode vm_mm; /* mapping mode */ -}; +static void zspage_lock_init(struct zspage *zspage) +{ + static struct lock_class_key __key; + struct zspage_lock *zsl = &zspage->zsl; + + lockdep_init_map(&zsl->dep_map, "zspage->lock", &__key, 0); + spin_lock_init(&zsl->lock); + zsl->cnt = ZS_PAGE_UNLOCKED; +} + +/* + * The zspage lock can be held from atomic contexts, but it needs to remain + * preemptible when held for reading because it remains held outside of those + * atomic contexts, otherwise we unnecessarily lose preemptibility. + * + * To achieve this, the following rules are enforced on readers and writers: + * + * - Writers are blocked by both writers and readers, while readers are only + * blocked by writers (i.e. normal rwlock semantics). + * + * - Writers are always atomic (to allow readers to spin waiting for them). + * + * - Writers always use trylock (as the lock may be held be sleeping readers). + * + * - Readers may spin on the lock (as they can only wait for atomic writers). + * + * - Readers may sleep while holding the lock (as writes only use trylock). + */ +static void zspage_read_lock(struct zspage *zspage) +{ + struct zspage_lock *zsl = &zspage->zsl; + + rwsem_acquire_read(&zsl->dep_map, 0, 0, _RET_IP_); + + spin_lock(&zsl->lock); + zsl->cnt++; + spin_unlock(&zsl->lock); + + lock_acquired(&zsl->dep_map, _RET_IP_); +} + +static void zspage_read_unlock(struct zspage *zspage) +{ + struct zspage_lock *zsl = &zspage->zsl; + + rwsem_release(&zsl->dep_map, _RET_IP_); + + spin_lock(&zsl->lock); + zsl->cnt--; + spin_unlock(&zsl->lock); +} + +static __must_check bool zspage_write_trylock(struct zspage *zspage) +{ + struct zspage_lock *zsl = &zspage->zsl; + + spin_lock(&zsl->lock); + if (zsl->cnt == ZS_PAGE_UNLOCKED) { + zsl->cnt = ZS_PAGE_WRLOCKED; + rwsem_acquire(&zsl->dep_map, 0, 1, _RET_IP_); + lock_acquired(&zsl->dep_map, _RET_IP_); + return true; + } + + spin_unlock(&zsl->lock); + return false; +} + +static void zspage_write_unlock(struct zspage *zspage) +{ + struct zspage_lock *zsl = &zspage->zsl; + + rwsem_release(&zsl->dep_map, _RET_IP_); + + zsl->cnt = ZS_PAGE_UNLOCKED; + spin_unlock(&zsl->lock); +} + +/* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */ +static void SetZsHugePage(struct zspage *zspage) +{ + zspage->huge = 1; +} + +static bool ZsHugePage(struct zspage *zspage) +{ + return zspage->huge; +} #ifdef CONFIG_COMPACTION -static int zs_register_migration(struct zs_pool *pool); -static void zs_unregister_migration(struct zs_pool *pool); -static void migrate_lock_init(struct zspage *zspage); -static void migrate_read_lock(struct zspage *zspage); -static void migrate_read_unlock(struct zspage *zspage); static void kick_deferred_free(struct zs_pool *pool); static void init_deferred_free(struct zs_pool *pool); static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage); #else -static int zsmalloc_mount(void) { return 0; } -static void zsmalloc_unmount(void) {} -static int zs_register_migration(struct zs_pool *pool) { return 0; } -static void zs_unregister_migration(struct zs_pool *pool) {} -static void migrate_lock_init(struct zspage *zspage) {} -static void migrate_read_lock(struct zspage *zspage) {} -static void migrate_read_unlock(struct zspage *zspage) {} static void kick_deferred_free(struct zs_pool *pool) {} static void init_deferred_free(struct zs_pool *pool) {} static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {} @@ -320,17 +372,27 @@ static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) {} static int create_cache(struct zs_pool *pool) { - pool->handle_cachep = kmem_cache_create("zs_handle", ZS_HANDLE_SIZE, - 0, 0, NULL); + char *name; + + name = kasprintf(GFP_KERNEL, "zs_handle-%s", pool->name); + if (!name) + return -ENOMEM; + pool->handle_cachep = kmem_cache_create(name, ZS_HANDLE_SIZE, + 0, 0, NULL); + kfree(name); if (!pool->handle_cachep) - return 1; + return -EINVAL; - pool->zspage_cachep = kmem_cache_create("zspage", sizeof(struct zspage), - 0, 0, NULL); + name = kasprintf(GFP_KERNEL, "zspage-%s", pool->name); + if (!name) + return -ENOMEM; + pool->zspage_cachep = kmem_cache_create(name, sizeof(struct zspage), + 0, 0, NULL); + kfree(name); if (!pool->zspage_cachep) { kmem_cache_destroy(pool->handle_cachep); pool->handle_cachep = NULL; - return 1; + return -EINVAL; } return 0; @@ -355,7 +417,7 @@ static void cache_free_handle(struct zs_pool *pool, unsigned long handle) static struct zspage *cache_alloc_zspage(struct zs_pool *pool, gfp_t flags) { - return kmem_cache_alloc(pool->zspage_cachep, + return kmem_cache_zalloc(pool->zspage_cachep, flags & ~(__GFP_HIGHMEM|__GFP_MOVABLE)); } @@ -364,104 +426,15 @@ static void cache_free_zspage(struct zs_pool *pool, struct zspage *zspage) kmem_cache_free(pool->zspage_cachep, zspage); } +/* class->lock(which owns the handle) synchronizes races */ static void record_obj(unsigned long handle, unsigned long obj) { - /* - * lsb of @obj represents handle lock while other bits - * represent object value the handle is pointing so - * updating shouldn't do store tearing. - */ - WRITE_ONCE(*(unsigned long *)handle, obj); -} - -/* zpool driver */ - -#ifdef CONFIG_ZPOOL - -static void *zs_zpool_create(const char *name, gfp_t gfp, - const struct zpool_ops *zpool_ops, - struct zpool *zpool) -{ - /* - * Ignore global gfp flags: zs_malloc() may be invoked from - * different contexts and its caller must provide a valid - * gfp mask. - */ - return zs_create_pool(name); -} - -static void zs_zpool_destroy(void *pool) -{ - zs_destroy_pool(pool); -} - -static int zs_zpool_malloc(void *pool, size_t size, gfp_t gfp, - unsigned long *handle) -{ - *handle = zs_malloc(pool, size, gfp); - return *handle ? 0 : -1; -} -static void zs_zpool_free(void *pool, unsigned long handle) -{ - zs_free(pool, handle); -} - -static void *zs_zpool_map(void *pool, unsigned long handle, - enum zpool_mapmode mm) -{ - enum zs_mapmode zs_mm; - - switch (mm) { - case ZPOOL_MM_RO: - zs_mm = ZS_MM_RO; - break; - case ZPOOL_MM_WO: - zs_mm = ZS_MM_WO; - break; - case ZPOOL_MM_RW: /* fall through */ - default: - zs_mm = ZS_MM_RW; - break; - } - - return zs_map_object(pool, handle, zs_mm); -} -static void zs_zpool_unmap(void *pool, unsigned long handle) -{ - zs_unmap_object(pool, handle); -} - -static u64 zs_zpool_total_size(void *pool) -{ - return zs_get_total_pages(pool) << PAGE_SHIFT; -} - -static struct zpool_driver zs_zpool_driver = { - .type = "zsmalloc", - .owner = THIS_MODULE, - .create = zs_zpool_create, - .destroy = zs_zpool_destroy, - .malloc = zs_zpool_malloc, - .free = zs_zpool_free, - .map = zs_zpool_map, - .unmap = zs_zpool_unmap, - .total_size = zs_zpool_total_size, -}; - -MODULE_ALIAS("zpool-zsmalloc"); -#endif /* CONFIG_ZPOOL */ - -/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */ -static DEFINE_PER_CPU(struct mapping_area, zs_map_area); - -static bool is_zspage_isolated(struct zspage *zspage) -{ - return zspage->isolated; + *(unsigned long *)handle = obj; } -static __maybe_unused int is_first_page(struct page *page) +static inline bool __maybe_unused is_first_zpdesc(struct zpdesc *zpdesc) { - return PagePrivate(page); + return PagePrivate(zpdesc_page(zpdesc)); } /* Protected by class->lock */ @@ -470,32 +443,35 @@ static inline int get_zspage_inuse(struct zspage *zspage) return zspage->inuse; } -static inline void set_zspage_inuse(struct zspage *zspage, int val) -{ - zspage->inuse = val; -} - static inline void mod_zspage_inuse(struct zspage *zspage, int val) { zspage->inuse += val; } -static inline struct page *get_first_page(struct zspage *zspage) +static struct zpdesc *get_first_zpdesc(struct zspage *zspage) { - struct page *first_page = zspage->first_page; + struct zpdesc *first_zpdesc = zspage->first_zpdesc; - VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); - return first_page; + VM_BUG_ON_PAGE(!is_first_zpdesc(first_zpdesc), zpdesc_page(first_zpdesc)); + return first_zpdesc; } -static inline int get_first_obj_offset(struct page *page) +#define FIRST_OBJ_PAGE_TYPE_MASK 0xffffff + +static inline unsigned int get_first_obj_offset(struct zpdesc *zpdesc) { - return page->units; + VM_WARN_ON_ONCE(!PageZsmalloc(zpdesc_page(zpdesc))); + return zpdesc->first_obj_offset & FIRST_OBJ_PAGE_TYPE_MASK; } -static inline void set_first_obj_offset(struct page *page, int offset) +static inline void set_first_obj_offset(struct zpdesc *zpdesc, unsigned int offset) { - page->units = offset; + /* With 24 bits available, we can support offsets into 16 MiB pages. */ + BUILD_BUG_ON(PAGE_SIZE > SZ_16M); + VM_WARN_ON_ONCE(!PageZsmalloc(zpdesc_page(zpdesc))); + VM_WARN_ON_ONCE(offset & ~FIRST_OBJ_PAGE_TYPE_MASK); + zpdesc->first_obj_offset &= ~FIRST_OBJ_PAGE_TYPE_MASK; + zpdesc->first_obj_offset |= offset & FIRST_OBJ_PAGE_TYPE_MASK; } static inline unsigned int get_freeobj(struct zspage *zspage) @@ -508,22 +484,10 @@ static inline void set_freeobj(struct zspage *zspage, unsigned int obj) zspage->freeobj = obj; } -static void get_zspage_mapping(struct zspage *zspage, - unsigned int *class_idx, - enum fullness_group *fullness) +static struct size_class *zspage_class(struct zs_pool *pool, + struct zspage *zspage) { - BUG_ON(zspage->magic != ZSPAGE_MAGIC); - - *fullness = zspage->fullness; - *class_idx = zspage->class; -} - -static void set_zspage_mapping(struct zspage *zspage, - unsigned int class_idx, - enum fullness_group fullness) -{ - zspage->class = class_idx; - zspage->fullness = fullness; + return pool->size_class[zspage->class]; } /* @@ -531,7 +495,7 @@ static void set_zspage_mapping(struct zspage *zspage, * class maintains a list of zspages where each zspage is divided * into equal sized chunks. Each allocation falls into one of these * classes depending on its size. This function returns index of the - * size class which has chunk size big enough to hold the give size. + * size class which has chunk size big enough to hold the given size. */ static int get_size_class_index(int size) { @@ -544,23 +508,19 @@ static int get_size_class_index(int size) return min_t(int, ZS_SIZE_CLASSES - 1, idx); } -/* type can be of enum type zs_stat_type or fullness_group */ -static inline void zs_stat_inc(struct size_class *class, - int type, unsigned long cnt) +static inline void class_stat_add(struct size_class *class, int type, + unsigned long cnt) { class->stats.objs[type] += cnt; } -/* type can be of enum type zs_stat_type or fullness_group */ -static inline void zs_stat_dec(struct size_class *class, - int type, unsigned long cnt) +static inline void class_stat_sub(struct size_class *class, int type, + unsigned long cnt) { class->stats.objs[type] -= cnt; } -/* type can be of enum type zs_stat_type or fullness_group */ -static inline unsigned long zs_stat_get(struct size_class *class, - int type) +static inline unsigned long class_stat_read(struct size_class *class, int type) { return class->stats.objs[type]; } @@ -575,8 +535,6 @@ static void __init zs_stat_init(void) } zs_stat_root = debugfs_create_dir("zsmalloc", NULL); - if (!zs_stat_root) - pr_warn("debugfs 'zsmalloc' stat dir creation failed\n"); } static void __exit zs_stat_exit(void) @@ -588,32 +546,38 @@ static unsigned long zs_can_compact(struct size_class *class); static int zs_stats_size_show(struct seq_file *s, void *v) { - int i; + int i, fg; struct zs_pool *pool = s->private; struct size_class *class; int objs_per_zspage; - unsigned long class_almost_full, class_almost_empty; unsigned long obj_allocated, obj_used, pages_used, freeable; - unsigned long total_class_almost_full = 0, total_class_almost_empty = 0; unsigned long total_objs = 0, total_used_objs = 0, total_pages = 0; unsigned long total_freeable = 0; + unsigned long inuse_totals[NR_FULLNESS_GROUPS] = {0, }; - seq_printf(s, " %5s %5s %11s %12s %13s %10s %10s %16s %8s\n", - "class", "size", "almost_full", "almost_empty", + seq_printf(s, " %5s %5s %9s %9s %9s %9s %9s %9s %9s %9s %9s %9s %9s %13s %10s %10s %16s %8s\n", + "class", "size", "10%", "20%", "30%", "40%", + "50%", "60%", "70%", "80%", "90%", "99%", "100%", "obj_allocated", "obj_used", "pages_used", "pages_per_zspage", "freeable"); for (i = 0; i < ZS_SIZE_CLASSES; i++) { + class = pool->size_class[i]; if (class->index != i) continue; spin_lock(&class->lock); - class_almost_full = zs_stat_get(class, CLASS_ALMOST_FULL); - class_almost_empty = zs_stat_get(class, CLASS_ALMOST_EMPTY); - obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); - obj_used = zs_stat_get(class, OBJ_USED); + + seq_printf(s, " %5u %5u ", i, class->size); + for (fg = ZS_INUSE_RATIO_10; fg < NR_FULLNESS_GROUPS; fg++) { + inuse_totals[fg] += class_stat_read(class, fg); + seq_printf(s, "%9lu ", class_stat_read(class, fg)); + } + + obj_allocated = class_stat_read(class, ZS_OBJS_ALLOCATED); + obj_used = class_stat_read(class, ZS_OBJS_INUSE); freeable = zs_can_compact(class); spin_unlock(&class->lock); @@ -621,14 +585,10 @@ static int zs_stats_size_show(struct seq_file *s, void *v) pages_used = obj_allocated / objs_per_zspage * class->pages_per_zspage; - seq_printf(s, " %5u %5u %11lu %12lu %13lu" - " %10lu %10lu %16d %8lu\n", - i, class->size, class_almost_full, class_almost_empty, - obj_allocated, obj_used, pages_used, - class->pages_per_zspage, freeable); + seq_printf(s, "%13lu %10lu %10lu %16d %8lu\n", + obj_allocated, obj_used, pages_used, + class->pages_per_zspage, freeable); - total_class_almost_full += class_almost_full; - total_class_almost_empty += class_almost_empty; total_objs += obj_allocated; total_used_objs += obj_used; total_pages += pages_used; @@ -636,10 +596,14 @@ static int zs_stats_size_show(struct seq_file *s, void *v) } seq_puts(s, "\n"); - seq_printf(s, " %5s %5s %11lu %12lu %13lu %10lu %10lu %16s %8lu\n", - "Total", "", total_class_almost_full, - total_class_almost_empty, total_objs, - total_used_objs, total_pages, "", total_freeable); + seq_printf(s, " %5s %5s ", "Total", ""); + + for (fg = ZS_INUSE_RATIO_10; fg < NR_FULLNESS_GROUPS; fg++) + seq_printf(s, "%9lu ", inuse_totals[fg]); + + seq_printf(s, "%13lu %10lu %10lu %16s %8lu\n", + total_objs, total_used_objs, total_pages, "", + total_freeable); return 0; } @@ -647,29 +611,15 @@ DEFINE_SHOW_ATTRIBUTE(zs_stats_size); static void zs_pool_stat_create(struct zs_pool *pool, const char *name) { - struct dentry *entry; - if (!zs_stat_root) { pr_warn("no root stat dir, not creating <%s> stat dir\n", name); return; } - entry = debugfs_create_dir(name, zs_stat_root); - if (!entry) { - pr_warn("debugfs dir <%s> creation failed\n", name); - return; - } - pool->stat_dentry = entry; - - entry = debugfs_create_file("classes", S_IFREG | 0444, - pool->stat_dentry, pool, - &zs_stats_size_fops); - if (!entry) { - pr_warn("%s: debugfs file entry <%s> creation failed\n", - name, "classes"); - debugfs_remove_recursive(pool->stat_dentry); - pool->stat_dentry = NULL; - } + pool->stat_dentry = debugfs_create_dir(name, zs_stat_root); + + debugfs_create_file("classes", S_IFREG | 0444, pool->stat_dentry, pool, + &zs_stats_size_fops); } static void zs_pool_stat_destroy(struct zs_pool *pool) @@ -698,30 +648,28 @@ static inline void zs_pool_stat_destroy(struct zs_pool *pool) /* * For each size class, zspages are divided into different groups - * depending on how "full" they are. This was done so that we could - * easily find empty or nearly empty zspages when we try to shrink - * the pool (not yet implemented). This function returns fullness + * depending on their usage ratio. This function returns fullness * status of the given page. */ -static enum fullness_group get_fullness_group(struct size_class *class, - struct zspage *zspage) +static int get_fullness_group(struct size_class *class, struct zspage *zspage) { - int inuse, objs_per_zspage; - enum fullness_group fg; + int inuse, objs_per_zspage, ratio; inuse = get_zspage_inuse(zspage); objs_per_zspage = class->objs_per_zspage; if (inuse == 0) - fg = ZS_EMPTY; - else if (inuse == objs_per_zspage) - fg = ZS_FULL; - else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac) - fg = ZS_ALMOST_EMPTY; - else - fg = ZS_ALMOST_FULL; + return ZS_INUSE_RATIO_0; + if (inuse == objs_per_zspage) + return ZS_INUSE_RATIO_100; - return fg; + ratio = 100 * inuse / objs_per_zspage; + /* + * Take integer division into consideration: a page with one inuse + * object out of 127 possible, will end up having 0 usage ratio, + * which is wrong as it belongs in ZS_INUSE_RATIO_10 fullness group. + */ + return ratio / 10 + 1; } /* @@ -732,150 +680,97 @@ static enum fullness_group get_fullness_group(struct size_class *class, */ static void insert_zspage(struct size_class *class, struct zspage *zspage, - enum fullness_group fullness) + int fullness) { - struct zspage *head; - - zs_stat_inc(class, fullness, 1); - head = list_first_entry_or_null(&class->fullness_list[fullness], - struct zspage, list); - /* - * We want to see more ZS_FULL pages and less almost empty/full. - * Put pages with higher ->inuse first. - */ - if (head) { - if (get_zspage_inuse(zspage) < get_zspage_inuse(head)) { - list_add(&zspage->list, &head->list); - return; - } - } + class_stat_add(class, fullness, 1); list_add(&zspage->list, &class->fullness_list[fullness]); + zspage->fullness = fullness; } /* * This function removes the given zspage from the freelist identified * by <class, fullness_group>. */ -static void remove_zspage(struct size_class *class, - struct zspage *zspage, - enum fullness_group fullness) +static void remove_zspage(struct size_class *class, struct zspage *zspage) { + int fullness = zspage->fullness; + VM_BUG_ON(list_empty(&class->fullness_list[fullness])); - VM_BUG_ON(is_zspage_isolated(zspage)); list_del_init(&zspage->list); - zs_stat_dec(class, fullness, 1); + class_stat_sub(class, fullness, 1); } /* * Each size class maintains zspages in different fullness groups depending * on the number of live objects they contain. When allocating or freeing - * objects, the fullness status of the page can change, say, from ALMOST_FULL - * to ALMOST_EMPTY when freeing an object. This function checks if such - * a status change has occurred for the given page and accordingly moves the - * page from the freelist of the old fullness group to that of the new - * fullness group. + * objects, the fullness status of the page can change, for instance, from + * INUSE_RATIO_80 to INUSE_RATIO_70 when freeing an object. This function + * checks if such a status change has occurred for the given page and + * accordingly moves the page from the list of the old fullness group to that + * of the new fullness group. */ -static enum fullness_group fix_fullness_group(struct size_class *class, - struct zspage *zspage) +static int fix_fullness_group(struct size_class *class, struct zspage *zspage) { - int class_idx; - enum fullness_group currfg, newfg; + int newfg; - get_zspage_mapping(zspage, &class_idx, &currfg); newfg = get_fullness_group(class, zspage); - if (newfg == currfg) + if (newfg == zspage->fullness) goto out; - if (!is_zspage_isolated(zspage)) { - remove_zspage(class, zspage, currfg); - insert_zspage(class, zspage, newfg); - } - - set_zspage_mapping(zspage, class_idx, newfg); - + remove_zspage(class, zspage); + insert_zspage(class, zspage, newfg); out: return newfg; } -/* - * We have to decide on how many pages to link together - * to form a zspage for each size class. This is important - * to reduce wastage due to unusable space left at end of - * each zspage which is given as: - * wastage = Zp % class_size - * usage = Zp - wastage - * where Zp = zspage size = k * PAGE_SIZE where k = 1, 2, ... - * - * For example, for size class of 3/8 * PAGE_SIZE, we should - * link together 3 PAGE_SIZE sized pages to form a zspage - * since then we can perfectly fit in 8 such objects. - */ -static int get_pages_per_zspage(int class_size) +static struct zspage *get_zspage(struct zpdesc *zpdesc) { - int i, max_usedpc = 0; - /* zspage order which gives maximum used size per KB */ - int max_usedpc_order = 1; - - for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { - int zspage_size; - int waste, usedpc; - - zspage_size = i * PAGE_SIZE; - waste = zspage_size % class_size; - usedpc = (zspage_size - waste) * 100 / zspage_size; - - if (usedpc > max_usedpc) { - max_usedpc = usedpc; - max_usedpc_order = i; - } - } - - return max_usedpc_order; -} - -static struct zspage *get_zspage(struct page *page) -{ - struct zspage *zspage = (struct zspage *)page->private; + struct zspage *zspage = zpdesc->zspage; BUG_ON(zspage->magic != ZSPAGE_MAGIC); return zspage; } -static struct page *get_next_page(struct page *page) +static struct zpdesc *get_next_zpdesc(struct zpdesc *zpdesc) { - if (unlikely(PageHugeObject(page))) + struct zspage *zspage = get_zspage(zpdesc); + + if (unlikely(ZsHugePage(zspage))) return NULL; - return page->freelist; + return zpdesc->next; } /** - * obj_to_location - get (<page>, <obj_idx>) from encoded object value + * obj_to_location - get (<zpdesc>, <obj_idx>) from encoded object value * @obj: the encoded object value - * @page: page object resides in zspage + * @zpdesc: zpdesc object resides in zspage * @obj_idx: object index */ -static void obj_to_location(unsigned long obj, struct page **page, +static void obj_to_location(unsigned long obj, struct zpdesc **zpdesc, unsigned int *obj_idx) { - obj >>= OBJ_TAG_BITS; - *page = pfn_to_page(obj >> OBJ_INDEX_BITS); + *zpdesc = pfn_zpdesc(obj >> OBJ_INDEX_BITS); *obj_idx = (obj & OBJ_INDEX_MASK); } +static void obj_to_zpdesc(unsigned long obj, struct zpdesc **zpdesc) +{ + *zpdesc = pfn_zpdesc(obj >> OBJ_INDEX_BITS); +} + /** - * location_to_obj - get obj value encoded from (<page>, <obj_idx>) - * @page: page object resides in zspage + * location_to_obj - get obj value encoded from (<zpdesc>, <obj_idx>) + * @zpdesc: zpdesc object resides in zspage * @obj_idx: object index */ -static unsigned long location_to_obj(struct page *page, unsigned int obj_idx) +static unsigned long location_to_obj(struct zpdesc *zpdesc, unsigned int obj_idx) { unsigned long obj; - obj = page_to_pfn(page) << OBJ_INDEX_BITS; + obj = zpdesc_pfn(zpdesc) << OBJ_INDEX_BITS; obj |= obj_idx & OBJ_INDEX_MASK; - obj <<= OBJ_TAG_BITS; return obj; } @@ -885,52 +780,43 @@ static unsigned long handle_to_obj(unsigned long handle) return *(unsigned long *)handle; } -static unsigned long obj_to_head(struct page *page, void *obj) +static inline bool obj_allocated(struct zpdesc *zpdesc, void *obj, + unsigned long *phandle) { - if (unlikely(PageHugeObject(page))) { - VM_BUG_ON_PAGE(!is_first_page(page), page); - return page->index; - } else - return *(unsigned long *)obj; -} + unsigned long handle; + struct zspage *zspage = get_zspage(zpdesc); -static inline int testpin_tag(unsigned long handle) -{ - return bit_spin_is_locked(HANDLE_PIN_BIT, (unsigned long *)handle); -} + if (unlikely(ZsHugePage(zspage))) { + VM_BUG_ON_PAGE(!is_first_zpdesc(zpdesc), zpdesc_page(zpdesc)); + handle = zpdesc->handle; + } else + handle = *(unsigned long *)obj; -static inline int trypin_tag(unsigned long handle) -{ - return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle); -} + if (!(handle & OBJ_ALLOCATED_TAG)) + return false; -static void pin_tag(unsigned long handle) -{ - bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle); + /* Clear all tags before returning the handle */ + *phandle = handle & ~OBJ_TAG_MASK; + return true; } -static void unpin_tag(unsigned long handle) +static void reset_zpdesc(struct zpdesc *zpdesc) { - bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle); -} + struct page *page = zpdesc_page(zpdesc); -static void reset_page(struct page *page) -{ - __ClearPageMovable(page); ClearPagePrivate(page); - set_page_private(page, 0); - page_mapcount_reset(page); - ClearPageHugeObject(page); - page->freelist = NULL; + zpdesc->zspage = NULL; + zpdesc->next = NULL; + /* PageZsmalloc is sticky until the page is freed to the buddy. */ } static int trylock_zspage(struct zspage *zspage) { - struct page *cursor, *fail; + struct zpdesc *cursor, *fail; - for (cursor = get_first_page(zspage); cursor != NULL; cursor = - get_next_page(cursor)) { - if (!trylock_page(cursor)) { + for (cursor = get_first_zpdesc(zspage); cursor != NULL; cursor = + get_next_zpdesc(cursor)) { + if (!zpdesc_trylock(cursor)) { fail = cursor; goto unlock; } @@ -938,9 +824,9 @@ static int trylock_zspage(struct zspage *zspage) return 1; unlock: - for (cursor = get_first_page(zspage); cursor != fail; cursor = - get_next_page(cursor)) - unlock_page(cursor); + for (cursor = get_first_zpdesc(zspage); cursor != fail; cursor = + get_next_zpdesc(cursor)) + zpdesc_unlock(cursor); return 0; } @@ -948,33 +834,28 @@ unlock: static void __free_zspage(struct zs_pool *pool, struct size_class *class, struct zspage *zspage) { - struct page *page, *next; - enum fullness_group fg; - unsigned int class_idx; - - get_zspage_mapping(zspage, &class_idx, &fg); + struct zpdesc *zpdesc, *next; assert_spin_locked(&class->lock); VM_BUG_ON(get_zspage_inuse(zspage)); - VM_BUG_ON(fg != ZS_EMPTY); + VM_BUG_ON(zspage->fullness != ZS_INUSE_RATIO_0); - next = page = get_first_page(zspage); + next = zpdesc = get_first_zpdesc(zspage); do { - VM_BUG_ON_PAGE(!PageLocked(page), page); - next = get_next_page(page); - reset_page(page); - unlock_page(page); - dec_zone_page_state(page, NR_ZSPAGES); - put_page(page); - page = next; - } while (page != NULL); + VM_BUG_ON_PAGE(!zpdesc_is_locked(zpdesc), zpdesc_page(zpdesc)); + next = get_next_zpdesc(zpdesc); + reset_zpdesc(zpdesc); + zpdesc_unlock(zpdesc); + zpdesc_dec_zone_page_state(zpdesc); + zpdesc_put(zpdesc); + zpdesc = next; + } while (zpdesc != NULL); cache_free_zspage(pool, zspage); - zs_stat_dec(class, OBJ_ALLOCATED, class->objs_per_zspage); - atomic_long_sub(class->pages_per_zspage, - &pool->pages_allocated); + class_stat_sub(class, ZS_OBJS_ALLOCATED, class->objs_per_zspage); + atomic_long_sub(class->pages_per_zspage, &pool->pages_allocated); } static void free_zspage(struct zs_pool *pool, struct size_class *class, @@ -983,12 +864,17 @@ static void free_zspage(struct zs_pool *pool, struct size_class *class, VM_BUG_ON(get_zspage_inuse(zspage)); VM_BUG_ON(list_empty(&zspage->list)); + /* + * Since zs_free couldn't be sleepable, this function cannot call + * lock_page. The page locks trylock_zspage got will be released + * by __free_zspage. + */ if (!trylock_zspage(zspage)) { kick_deferred_free(pool); return; } - remove_zspage(class, zspage, ZS_EMPTY); + remove_zspage(class, zspage); __free_zspage(pool, class, zspage); } @@ -997,16 +883,16 @@ static void init_zspage(struct size_class *class, struct zspage *zspage) { unsigned int freeobj = 1; unsigned long off = 0; - struct page *page = get_first_page(zspage); + struct zpdesc *zpdesc = get_first_zpdesc(zspage); - while (page) { - struct page *next_page; + while (zpdesc) { + struct zpdesc *next_zpdesc; struct link_free *link; void *vaddr; - set_first_obj_offset(page, off); + set_first_obj_offset(zpdesc, off); - vaddr = kmap_atomic(page); + vaddr = kmap_local_zpdesc(zpdesc); link = (struct link_free *)vaddr + off / sizeof(*link); while ((off += class->size) < PAGE_SIZE) { @@ -1019,8 +905,8 @@ static void init_zspage(struct size_class *class, struct zspage *zspage) * page, which must point to the first object on the next * page (if present) */ - next_page = get_next_page(page); - if (next_page) { + next_zpdesc = get_next_zpdesc(zpdesc); + if (next_zpdesc) { link->next = freeobj++ << OBJ_TAG_BITS; } else { /* @@ -1029,8 +915,8 @@ static void init_zspage(struct size_class *class, struct zspage *zspage) */ link->next = -1UL << OBJ_TAG_BITS; } - kunmap_atomic(vaddr); - page = next_page; + kunmap_local(vaddr); + zpdesc = next_zpdesc; off %= PAGE_SIZE; } @@ -1038,35 +924,35 @@ static void init_zspage(struct size_class *class, struct zspage *zspage) } static void create_page_chain(struct size_class *class, struct zspage *zspage, - struct page *pages[]) + struct zpdesc *zpdescs[]) { int i; - struct page *page; - struct page *prev_page = NULL; - int nr_pages = class->pages_per_zspage; + struct zpdesc *zpdesc; + struct zpdesc *prev_zpdesc = NULL; + int nr_zpdescs = class->pages_per_zspage; /* * Allocate individual pages and link them together as: - * 1. all pages are linked together using page->freelist - * 2. each sub-page point to zspage using page->private + * 1. all pages are linked together using zpdesc->next + * 2. each sub-page point to zspage using zpdesc->zspage * - * we set PG_private to identify the first page (i.e. no other sub-page + * we set PG_private to identify the first zpdesc (i.e. no other zpdesc * has this flag set). */ - for (i = 0; i < nr_pages; i++) { - page = pages[i]; - set_page_private(page, (unsigned long)zspage); - page->freelist = NULL; + for (i = 0; i < nr_zpdescs; i++) { + zpdesc = zpdescs[i]; + zpdesc->zspage = zspage; + zpdesc->next = NULL; if (i == 0) { - zspage->first_page = page; - SetPagePrivate(page); + zspage->first_zpdesc = zpdesc; + zpdesc_set_first(zpdesc); if (unlikely(class->objs_per_zspage == 1 && class->pages_per_zspage == 1)) - SetPageHugeObject(page); + SetZsHugePage(zspage); } else { - prev_page->freelist = page; + prev_zpdesc->next = zpdesc; } - prev_page = page; + prev_zpdesc = zpdesc; } } @@ -1074,38 +960,43 @@ static void create_page_chain(struct size_class *class, struct zspage *zspage, * Allocate a zspage for the given size class */ static struct zspage *alloc_zspage(struct zs_pool *pool, - struct size_class *class, - gfp_t gfp) + struct size_class *class, + gfp_t gfp, const int nid) { int i; - struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE]; + struct zpdesc *zpdescs[ZS_MAX_PAGES_PER_ZSPAGE]; struct zspage *zspage = cache_alloc_zspage(pool, gfp); if (!zspage) return NULL; - memset(zspage, 0, sizeof(struct zspage)); + if (!IS_ENABLED(CONFIG_COMPACTION)) + gfp &= ~__GFP_MOVABLE; + zspage->magic = ZSPAGE_MAGIC; - migrate_lock_init(zspage); + zspage->pool = pool; + zspage->class = class->index; + zspage_lock_init(zspage); for (i = 0; i < class->pages_per_zspage; i++) { - struct page *page; + struct zpdesc *zpdesc; - page = alloc_page(gfp); - if (!page) { + zpdesc = alloc_zpdesc(gfp, nid); + if (!zpdesc) { while (--i >= 0) { - dec_zone_page_state(pages[i], NR_ZSPAGES); - __free_page(pages[i]); + zpdesc_dec_zone_page_state(zpdescs[i]); + free_zpdesc(zpdescs[i]); } cache_free_zspage(pool, zspage); return NULL; } + __zpdesc_set_zsmalloc(zpdesc); - inc_zone_page_state(page, NR_ZSPAGES); - pages[i] = page; + zpdesc_inc_zone_page_state(zpdesc); + zpdescs[i] = zpdesc; } - create_page_chain(class, zspage, pages); + create_page_chain(class, zspage, zpdescs); init_zspage(class, zspage); return zspage; @@ -1116,9 +1007,9 @@ static struct zspage *find_get_zspage(struct size_class *class) int i; struct zspage *zspage; - for (i = ZS_ALMOST_FULL; i >= ZS_EMPTY; i--) { + for (i = ZS_INUSE_RATIO_99; i >= ZS_INUSE_RATIO_0; i--) { zspage = list_first_entry_or_null(&class->fullness_list[i], - struct zspage, list); + struct zspage, list); if (zspage) break; } @@ -1126,145 +1017,6 @@ static struct zspage *find_get_zspage(struct size_class *class) return zspage; } -#ifdef CONFIG_PGTABLE_MAPPING -static inline int __zs_cpu_up(struct mapping_area *area) -{ - /* - * Make sure we don't leak memory if a cpu UP notification - * and zs_init() race and both call zs_cpu_up() on the same cpu - */ - if (area->vm) - return 0; - area->vm = alloc_vm_area(PAGE_SIZE * 2, NULL); - if (!area->vm) - return -ENOMEM; - return 0; -} - -static inline void __zs_cpu_down(struct mapping_area *area) -{ - if (area->vm) - free_vm_area(area->vm); - area->vm = NULL; -} - -static inline void *__zs_map_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - BUG_ON(map_vm_area(area->vm, PAGE_KERNEL, pages)); - area->vm_addr = area->vm->addr; - return area->vm_addr + off; -} - -static inline void __zs_unmap_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - unsigned long addr = (unsigned long)area->vm_addr; - - unmap_kernel_range(addr, PAGE_SIZE * 2); -} - -#else /* CONFIG_PGTABLE_MAPPING */ - -static inline int __zs_cpu_up(struct mapping_area *area) -{ - /* - * Make sure we don't leak memory if a cpu UP notification - * and zs_init() race and both call zs_cpu_up() on the same cpu - */ - if (area->vm_buf) - return 0; - area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL); - if (!area->vm_buf) - return -ENOMEM; - return 0; -} - -static inline void __zs_cpu_down(struct mapping_area *area) -{ - kfree(area->vm_buf); - area->vm_buf = NULL; -} - -static void *__zs_map_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - int sizes[2]; - void *addr; - char *buf = area->vm_buf; - - /* disable page faults to match kmap_atomic() return conditions */ - pagefault_disable(); - - /* no read fastpath */ - if (area->vm_mm == ZS_MM_WO) - goto out; - - sizes[0] = PAGE_SIZE - off; - sizes[1] = size - sizes[0]; - - /* copy object to per-cpu buffer */ - addr = kmap_atomic(pages[0]); - memcpy(buf, addr + off, sizes[0]); - kunmap_atomic(addr); - addr = kmap_atomic(pages[1]); - memcpy(buf + sizes[0], addr, sizes[1]); - kunmap_atomic(addr); -out: - return area->vm_buf; -} - -static void __zs_unmap_object(struct mapping_area *area, - struct page *pages[2], int off, int size) -{ - int sizes[2]; - void *addr; - char *buf; - - /* no write fastpath */ - if (area->vm_mm == ZS_MM_RO) - goto out; - - buf = area->vm_buf; - buf = buf + ZS_HANDLE_SIZE; - size -= ZS_HANDLE_SIZE; - off += ZS_HANDLE_SIZE; - - sizes[0] = PAGE_SIZE - off; - sizes[1] = size - sizes[0]; - - /* copy per-cpu buffer to object */ - addr = kmap_atomic(pages[0]); - memcpy(addr + off, buf, sizes[0]); - kunmap_atomic(addr); - addr = kmap_atomic(pages[1]); - memcpy(addr, buf + sizes[0], sizes[1]); - kunmap_atomic(addr); - -out: - /* enable page faults to match kunmap_atomic() return conditions */ - pagefault_enable(); -} - -#endif /* CONFIG_PGTABLE_MAPPING */ - -static int zs_cpu_prepare(unsigned int cpu) -{ - struct mapping_area *area; - - area = &per_cpu(zs_map_area, cpu); - return __zs_cpu_up(area); -} - -static int zs_cpu_dead(unsigned int cpu) -{ - struct mapping_area *area; - - area = &per_cpu(zs_map_area, cpu); - __zs_cpu_down(area); - return 0; -} - static bool can_merge(struct size_class *prev, int pages_per_zspage, int objs_per_zspage) { @@ -1280,123 +1032,162 @@ static bool zspage_full(struct size_class *class, struct zspage *zspage) return get_zspage_inuse(zspage) == class->objs_per_zspage; } -unsigned long zs_get_total_pages(struct zs_pool *pool) +static bool zspage_empty(struct zspage *zspage) { - return atomic_long_read(&pool->pages_allocated); + return get_zspage_inuse(zspage) == 0; } -EXPORT_SYMBOL_GPL(zs_get_total_pages); /** - * zs_map_object - get address of allocated object from handle. - * @pool: pool from which the object was allocated - * @handle: handle returned from zs_malloc - * @mm: maping mode to use - * - * Before using an object allocated from zs_malloc, it must be mapped using - * this function. When done with the object, it must be unmapped using - * zs_unmap_object. + * zs_lookup_class_index() - Returns index of the zsmalloc &size_class + * that hold objects of the provided size. + * @pool: zsmalloc pool to use + * @size: object size * - * Only one object can be mapped per cpu at a time. There is no protection - * against nested mappings. + * Context: Any context. * - * This function returns with preemption and page faults disabled. + * Return: the index of the zsmalloc &size_class that hold objects of the + * provided size. */ -void *zs_map_object(struct zs_pool *pool, unsigned long handle, - enum zs_mapmode mm) +unsigned int zs_lookup_class_index(struct zs_pool *pool, unsigned int size) +{ + struct size_class *class; + + class = pool->size_class[get_size_class_index(size)]; + + return class->index; +} +EXPORT_SYMBOL_GPL(zs_lookup_class_index); + +unsigned long zs_get_total_pages(struct zs_pool *pool) +{ + return atomic_long_read(&pool->pages_allocated); +} +EXPORT_SYMBOL_GPL(zs_get_total_pages); + +void *zs_obj_read_begin(struct zs_pool *pool, unsigned long handle, + void *local_copy) { struct zspage *zspage; - struct page *page; + struct zpdesc *zpdesc; unsigned long obj, off; unsigned int obj_idx; - - unsigned int class_idx; - enum fullness_group fg; struct size_class *class; - struct mapping_area *area; - struct page *pages[2]; - void *ret; - - /* - * Because we use per-cpu mapping areas shared among the - * pools/users, we can't allow mapping in interrupt context - * because it can corrupt another users mappings. - */ - BUG_ON(in_interrupt()); - - /* From now on, migration cannot move the object */ - pin_tag(handle); + void *addr; + /* Guarantee we can get zspage from handle safely */ + read_lock(&pool->lock); obj = handle_to_obj(handle); - obj_to_location(obj, &page, &obj_idx); - zspage = get_zspage(page); + obj_to_location(obj, &zpdesc, &obj_idx); + zspage = get_zspage(zpdesc); - /* migration cannot move any subpage in this zspage */ - migrate_read_lock(zspage); + /* Make sure migration doesn't move any pages in this zspage */ + zspage_read_lock(zspage); + read_unlock(&pool->lock); - get_zspage_mapping(zspage, &class_idx, &fg); - class = pool->size_class[class_idx]; - off = (class->size * obj_idx) & ~PAGE_MASK; + class = zspage_class(pool, zspage); + off = offset_in_page(class->size * obj_idx); - area = &get_cpu_var(zs_map_area); - area->vm_mm = mm; if (off + class->size <= PAGE_SIZE) { /* this object is contained entirely within a page */ - area->vm_addr = kmap_atomic(page); - ret = area->vm_addr + off; - goto out; + addr = kmap_local_zpdesc(zpdesc); + addr += off; + } else { + size_t sizes[2]; + + /* this object spans two pages */ + sizes[0] = PAGE_SIZE - off; + sizes[1] = class->size - sizes[0]; + addr = local_copy; + + memcpy_from_page(addr, zpdesc_page(zpdesc), + off, sizes[0]); + zpdesc = get_next_zpdesc(zpdesc); + memcpy_from_page(addr + sizes[0], + zpdesc_page(zpdesc), + 0, sizes[1]); } - /* this object spans two pages */ - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); + if (!ZsHugePage(zspage)) + addr += ZS_HANDLE_SIZE; - ret = __zs_map_object(area, pages, off, class->size); -out: - if (likely(!PageHugeObject(page))) - ret += ZS_HANDLE_SIZE; - - return ret; + return addr; } -EXPORT_SYMBOL_GPL(zs_map_object); +EXPORT_SYMBOL_GPL(zs_obj_read_begin); -void zs_unmap_object(struct zs_pool *pool, unsigned long handle) +void zs_obj_read_end(struct zs_pool *pool, unsigned long handle, + void *handle_mem) { struct zspage *zspage; - struct page *page; + struct zpdesc *zpdesc; unsigned long obj, off; unsigned int obj_idx; + struct size_class *class; + + obj = handle_to_obj(handle); + obj_to_location(obj, &zpdesc, &obj_idx); + zspage = get_zspage(zpdesc); + class = zspage_class(pool, zspage); + off = offset_in_page(class->size * obj_idx); + + if (off + class->size <= PAGE_SIZE) { + if (!ZsHugePage(zspage)) + off += ZS_HANDLE_SIZE; + handle_mem -= off; + kunmap_local(handle_mem); + } - unsigned int class_idx; - enum fullness_group fg; + zspage_read_unlock(zspage); +} +EXPORT_SYMBOL_GPL(zs_obj_read_end); + +void zs_obj_write(struct zs_pool *pool, unsigned long handle, + void *handle_mem, size_t mem_len) +{ + struct zspage *zspage; + struct zpdesc *zpdesc; + unsigned long obj, off; + unsigned int obj_idx; struct size_class *class; - struct mapping_area *area; + /* Guarantee we can get zspage from handle safely */ + read_lock(&pool->lock); obj = handle_to_obj(handle); - obj_to_location(obj, &page, &obj_idx); - zspage = get_zspage(page); - get_zspage_mapping(zspage, &class_idx, &fg); - class = pool->size_class[class_idx]; - off = (class->size * obj_idx) & ~PAGE_MASK; - - area = this_cpu_ptr(&zs_map_area); - if (off + class->size <= PAGE_SIZE) - kunmap_atomic(area->vm_addr); - else { - struct page *pages[2]; - - pages[0] = page; - pages[1] = get_next_page(page); - BUG_ON(!pages[1]); - - __zs_unmap_object(area, pages, off, class->size); + obj_to_location(obj, &zpdesc, &obj_idx); + zspage = get_zspage(zpdesc); + + /* Make sure migration doesn't move any pages in this zspage */ + zspage_read_lock(zspage); + read_unlock(&pool->lock); + + class = zspage_class(pool, zspage); + off = offset_in_page(class->size * obj_idx); + + if (!ZsHugePage(zspage)) + off += ZS_HANDLE_SIZE; + + if (off + mem_len <= PAGE_SIZE) { + /* this object is contained entirely within a page */ + void *dst = kmap_local_zpdesc(zpdesc); + + memcpy(dst + off, handle_mem, mem_len); + kunmap_local(dst); + } else { + /* this object spans two pages */ + size_t sizes[2]; + + sizes[0] = PAGE_SIZE - off; + sizes[1] = mem_len - sizes[0]; + + memcpy_to_page(zpdesc_page(zpdesc), off, + handle_mem, sizes[0]); + zpdesc = get_next_zpdesc(zpdesc); + memcpy_to_page(zpdesc_page(zpdesc), 0, + handle_mem + sizes[0], sizes[1]); } - put_cpu_var(zs_map_area); - migrate_read_unlock(zspage); - unpin_tag(handle); + zspage_read_unlock(zspage); } -EXPORT_SYMBOL_GPL(zs_unmap_object); +EXPORT_SYMBOL_GPL(zs_obj_write); /** * zs_huge_class_size() - Returns the size (in bytes) of the first huge @@ -1417,43 +1208,43 @@ size_t zs_huge_class_size(struct zs_pool *pool) } EXPORT_SYMBOL_GPL(zs_huge_class_size); -static unsigned long obj_malloc(struct size_class *class, +static unsigned long obj_malloc(struct zs_pool *pool, struct zspage *zspage, unsigned long handle) { - int i, nr_page, offset; + int i, nr_zpdesc, offset; unsigned long obj; struct link_free *link; + struct size_class *class; - struct page *m_page; + struct zpdesc *m_zpdesc; unsigned long m_offset; void *vaddr; - handle |= OBJ_ALLOCATED_TAG; + class = pool->size_class[zspage->class]; obj = get_freeobj(zspage); offset = obj * class->size; - nr_page = offset >> PAGE_SHIFT; - m_offset = offset & ~PAGE_MASK; - m_page = get_first_page(zspage); + nr_zpdesc = offset >> PAGE_SHIFT; + m_offset = offset_in_page(offset); + m_zpdesc = get_first_zpdesc(zspage); - for (i = 0; i < nr_page; i++) - m_page = get_next_page(m_page); + for (i = 0; i < nr_zpdesc; i++) + m_zpdesc = get_next_zpdesc(m_zpdesc); - vaddr = kmap_atomic(m_page); + vaddr = kmap_local_zpdesc(m_zpdesc); link = (struct link_free *)vaddr + m_offset / sizeof(*link); set_freeobj(zspage, link->next >> OBJ_TAG_BITS); - if (likely(!PageHugeObject(m_page))) + if (likely(!ZsHugePage(zspage))) /* record handle in the header of allocated chunk */ - link->handle = handle; + link->handle = handle | OBJ_ALLOCATED_TAG; else - /* record handle to page->index */ - zspage->first_page->index = handle; + zspage->first_zpdesc->handle = handle | OBJ_ALLOCATED_TAG; - kunmap_atomic(vaddr); + kunmap_local(vaddr); mod_zspage_inuse(zspage, 1); - zs_stat_inc(class, OBJ_USED, 1); - obj = location_to_obj(m_page, obj); + obj = location_to_obj(m_zpdesc, obj); + record_obj(handle, obj); return obj; } @@ -1464,133 +1255,130 @@ static unsigned long obj_malloc(struct size_class *class, * @pool: pool to allocate from * @size: size of block to allocate * @gfp: gfp flags when allocating object + * @nid: The preferred node id to allocate new zspage (if needed) * * On success, handle to the allocated object is returned, - * otherwise 0. + * otherwise an ERR_PTR(). * Allocation requests with size > ZS_MAX_ALLOC_SIZE will fail. */ -unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp) +unsigned long zs_malloc(struct zs_pool *pool, size_t size, gfp_t gfp, + const int nid) { - unsigned long handle, obj; + unsigned long handle; struct size_class *class; - enum fullness_group newfg; + int newfg; struct zspage *zspage; - if (unlikely(!size || size > ZS_MAX_ALLOC_SIZE)) - return 0; + if (unlikely(!size)) + return (unsigned long)ERR_PTR(-EINVAL); + + if (unlikely(size > ZS_MAX_ALLOC_SIZE)) + return (unsigned long)ERR_PTR(-ENOSPC); handle = cache_alloc_handle(pool, gfp); if (!handle) - return 0; + return (unsigned long)ERR_PTR(-ENOMEM); /* extra space in chunk to keep the handle */ size += ZS_HANDLE_SIZE; class = pool->size_class[get_size_class_index(size)]; + /* class->lock effectively protects the zpage migration */ spin_lock(&class->lock); zspage = find_get_zspage(class); if (likely(zspage)) { - obj = obj_malloc(class, zspage, handle); + obj_malloc(pool, zspage, handle); /* Now move the zspage to another fullness group, if required */ fix_fullness_group(class, zspage); - record_obj(handle, obj); - spin_unlock(&class->lock); + class_stat_add(class, ZS_OBJS_INUSE, 1); - return handle; + goto out; } spin_unlock(&class->lock); - zspage = alloc_zspage(pool, class, gfp); + zspage = alloc_zspage(pool, class, gfp, nid); if (!zspage) { cache_free_handle(pool, handle); - return 0; + return (unsigned long)ERR_PTR(-ENOMEM); } spin_lock(&class->lock); - obj = obj_malloc(class, zspage, handle); + obj_malloc(pool, zspage, handle); newfg = get_fullness_group(class, zspage); insert_zspage(class, zspage, newfg); - set_zspage_mapping(zspage, class->index, newfg); - record_obj(handle, obj); - atomic_long_add(class->pages_per_zspage, - &pool->pages_allocated); - zs_stat_inc(class, OBJ_ALLOCATED, class->objs_per_zspage); + atomic_long_add(class->pages_per_zspage, &pool->pages_allocated); + class_stat_add(class, ZS_OBJS_ALLOCATED, class->objs_per_zspage); + class_stat_add(class, ZS_OBJS_INUSE, 1); /* We completely set up zspage so mark them as movable */ SetZsPageMovable(pool, zspage); +out: spin_unlock(&class->lock); return handle; } EXPORT_SYMBOL_GPL(zs_malloc); -static void obj_free(struct size_class *class, unsigned long obj) +static void obj_free(int class_size, unsigned long obj) { struct link_free *link; struct zspage *zspage; - struct page *f_page; + struct zpdesc *f_zpdesc; unsigned long f_offset; unsigned int f_objidx; void *vaddr; - obj &= ~OBJ_ALLOCATED_TAG; - obj_to_location(obj, &f_page, &f_objidx); - f_offset = (class->size * f_objidx) & ~PAGE_MASK; - zspage = get_zspage(f_page); - vaddr = kmap_atomic(f_page); + obj_to_location(obj, &f_zpdesc, &f_objidx); + f_offset = offset_in_page(class_size * f_objidx); + zspage = get_zspage(f_zpdesc); - /* Insert this object in containing zspage's freelist */ + vaddr = kmap_local_zpdesc(f_zpdesc); link = (struct link_free *)(vaddr + f_offset); - link->next = get_freeobj(zspage) << OBJ_TAG_BITS; - kunmap_atomic(vaddr); + + /* Insert this object in containing zspage's freelist */ + if (likely(!ZsHugePage(zspage))) + link->next = get_freeobj(zspage) << OBJ_TAG_BITS; + else + f_zpdesc->handle = 0; set_freeobj(zspage, f_objidx); + + kunmap_local(vaddr); mod_zspage_inuse(zspage, -1); - zs_stat_dec(class, OBJ_USED, 1); } void zs_free(struct zs_pool *pool, unsigned long handle) { struct zspage *zspage; - struct page *f_page; + struct zpdesc *f_zpdesc; unsigned long obj; - unsigned int f_objidx; - int class_idx; struct size_class *class; - enum fullness_group fullness; - bool isolated; + int fullness; - if (unlikely(!handle)) + if (IS_ERR_OR_NULL((void *)handle)) return; - pin_tag(handle); + /* + * The pool->lock protects the race with zpage's migration + * so it's safe to get the page from handle. + */ + read_lock(&pool->lock); obj = handle_to_obj(handle); - obj_to_location(obj, &f_page, &f_objidx); - zspage = get_zspage(f_page); - - migrate_read_lock(zspage); + obj_to_zpdesc(obj, &f_zpdesc); + zspage = get_zspage(f_zpdesc); + class = zspage_class(pool, zspage); + spin_lock(&class->lock); + read_unlock(&pool->lock); - get_zspage_mapping(zspage, &class_idx, &fullness); - class = pool->size_class[class_idx]; + class_stat_sub(class, ZS_OBJS_INUSE, 1); + obj_free(class->size, obj); - spin_lock(&class->lock); - obj_free(class, obj); fullness = fix_fullness_group(class, zspage); - if (fullness != ZS_EMPTY) { - migrate_read_unlock(zspage); - goto out; - } - - isolated = is_zspage_isolated(zspage); - migrate_read_unlock(zspage); - /* If zspage is isolated, zs_page_putback will free the zspage */ - if (likely(!isolated)) + if (fullness == ZS_INUSE_RATIO_0) free_zspage(pool, class, zspage); -out: spin_unlock(&class->lock); - unpin_tag(handle); cache_free_handle(pool, handle); } EXPORT_SYMBOL_GPL(zs_free); @@ -1598,7 +1386,7 @@ EXPORT_SYMBOL_GPL(zs_free); static void zs_object_copy(struct size_class *class, unsigned long dst, unsigned long src) { - struct page *s_page, *d_page; + struct zpdesc *s_zpdesc, *d_zpdesc; unsigned int s_objidx, d_objidx; unsigned long s_off, d_off; void *s_addr, *d_addr; @@ -1607,11 +1395,11 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, s_size = d_size = class->size; - obj_to_location(src, &s_page, &s_objidx); - obj_to_location(dst, &d_page, &d_objidx); + obj_to_location(src, &s_zpdesc, &s_objidx); + obj_to_location(dst, &d_zpdesc, &d_objidx); - s_off = (class->size * s_objidx) & ~PAGE_MASK; - d_off = (class->size * d_objidx) & ~PAGE_MASK; + s_off = offset_in_page(class->size * s_objidx); + d_off = offset_in_page(class->size * d_objidx); if (s_off + class->size > PAGE_SIZE) s_size = PAGE_SIZE - s_off; @@ -1619,8 +1407,8 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, if (d_off + class->size > PAGE_SIZE) d_size = PAGE_SIZE - d_off; - s_addr = kmap_atomic(s_page); - d_addr = kmap_atomic(d_page); + s_addr = kmap_local_zpdesc(s_zpdesc); + d_addr = kmap_local_zpdesc(d_zpdesc); while (1) { size = min(s_size, d_size); @@ -1635,27 +1423,34 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, d_off += size; d_size -= size; + /* + * Calling kunmap_local(d_addr) is necessary. kunmap_local() + * calls must occurs in reverse order of calls to kmap_local_page(). + * So, to call kunmap_local(s_addr) we should first call + * kunmap_local(d_addr). For more details see + * Documentation/mm/highmem.rst. + */ if (s_off >= PAGE_SIZE) { - kunmap_atomic(d_addr); - kunmap_atomic(s_addr); - s_page = get_next_page(s_page); - s_addr = kmap_atomic(s_page); - d_addr = kmap_atomic(d_page); + kunmap_local(d_addr); + kunmap_local(s_addr); + s_zpdesc = get_next_zpdesc(s_zpdesc); + s_addr = kmap_local_zpdesc(s_zpdesc); + d_addr = kmap_local_zpdesc(d_zpdesc); s_size = class->size - written; s_off = 0; } if (d_off >= PAGE_SIZE) { - kunmap_atomic(d_addr); - d_page = get_next_page(d_page); - d_addr = kmap_atomic(d_page); + kunmap_local(d_addr); + d_zpdesc = get_next_zpdesc(d_zpdesc); + d_addr = kmap_local_zpdesc(d_zpdesc); d_size = class->size - written; d_off = 0; } } - kunmap_atomic(d_addr); - kunmap_atomic(s_addr); + kunmap_local(d_addr); + kunmap_local(s_addr); } /* @@ -1663,115 +1458,93 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, * return handle. */ static unsigned long find_alloced_obj(struct size_class *class, - struct page *page, int *obj_idx) + struct zpdesc *zpdesc, int *obj_idx) { - unsigned long head; - int offset = 0; + unsigned int offset; int index = *obj_idx; unsigned long handle = 0; - void *addr = kmap_atomic(page); + void *addr = kmap_local_zpdesc(zpdesc); - offset = get_first_obj_offset(page); + offset = get_first_obj_offset(zpdesc); offset += class->size * index; while (offset < PAGE_SIZE) { - head = obj_to_head(page, addr + offset); - if (head & OBJ_ALLOCATED_TAG) { - handle = head & ~OBJ_ALLOCATED_TAG; - if (trypin_tag(handle)) - break; - handle = 0; - } + if (obj_allocated(zpdesc, addr + offset, &handle)) + break; offset += class->size; index++; } - kunmap_atomic(addr); + kunmap_local(addr); *obj_idx = index; return handle; } -struct zs_compact_control { - /* Source spage for migration which could be a subpage of zspage */ - struct page *s_page; - /* Destination page for migration which should be a first page - * of zspage. */ - struct page *d_page; - /* Starting object index within @s_page which used for live object - * in the subpage. */ - int obj_idx; -}; - -static int migrate_zspage(struct zs_pool *pool, struct size_class *class, - struct zs_compact_control *cc) +static void migrate_zspage(struct zs_pool *pool, struct zspage *src_zspage, + struct zspage *dst_zspage) { unsigned long used_obj, free_obj; unsigned long handle; - struct page *s_page = cc->s_page; - struct page *d_page = cc->d_page; - int obj_idx = cc->obj_idx; - int ret = 0; + int obj_idx = 0; + struct zpdesc *s_zpdesc = get_first_zpdesc(src_zspage); + struct size_class *class = pool->size_class[src_zspage->class]; while (1) { - handle = find_alloced_obj(class, s_page, &obj_idx); + handle = find_alloced_obj(class, s_zpdesc, &obj_idx); if (!handle) { - s_page = get_next_page(s_page); - if (!s_page) + s_zpdesc = get_next_zpdesc(s_zpdesc); + if (!s_zpdesc) break; obj_idx = 0; continue; } - /* Stop if there is no more space */ - if (zspage_full(class, get_zspage(d_page))) { - unpin_tag(handle); - ret = -ENOMEM; - break; - } - used_obj = handle_to_obj(handle); - free_obj = obj_malloc(class, get_zspage(d_page), handle); + free_obj = obj_malloc(pool, dst_zspage, handle); zs_object_copy(class, free_obj, used_obj); obj_idx++; - /* - * record_obj updates handle's value to free_obj and it will - * invalidate lock bit(ie, HANDLE_PIN_BIT) of handle, which - * breaks synchronization using pin_tag(e,g, zs_free) so - * let's keep the lock bit. - */ - free_obj |= BIT(HANDLE_PIN_BIT); - record_obj(handle, free_obj); - unpin_tag(handle); - obj_free(class, used_obj); - } + obj_free(class->size, used_obj); - /* Remember last position in this iteration */ - cc->s_page = s_page; - cc->obj_idx = obj_idx; + /* Stop if there is no more space */ + if (zspage_full(class, dst_zspage)) + break; - return ret; + /* Stop if there are no more objects to migrate */ + if (zspage_empty(src_zspage)) + break; + } } -static struct zspage *isolate_zspage(struct size_class *class, bool source) +static struct zspage *isolate_src_zspage(struct size_class *class) { - int i; struct zspage *zspage; - enum fullness_group fg[2] = {ZS_ALMOST_EMPTY, ZS_ALMOST_FULL}; + int fg; - if (!source) { - fg[0] = ZS_ALMOST_FULL; - fg[1] = ZS_ALMOST_EMPTY; + for (fg = ZS_INUSE_RATIO_10; fg <= ZS_INUSE_RATIO_99; fg++) { + zspage = list_first_entry_or_null(&class->fullness_list[fg], + struct zspage, list); + if (zspage) { + remove_zspage(class, zspage); + return zspage; + } } - for (i = 0; i < 2; i++) { - zspage = list_first_entry_or_null(&class->fullness_list[fg[i]], - struct zspage, list); + return zspage; +} + +static struct zspage *isolate_dst_zspage(struct size_class *class) +{ + struct zspage *zspage; + int fg; + + for (fg = ZS_INUSE_RATIO_99; fg >= ZS_INUSE_RATIO_10; fg--) { + zspage = list_first_entry_or_null(&class->fullness_list[fg], + struct zspage, list); if (zspage) { - VM_BUG_ON(is_zspage_isolated(zspage)); - remove_zspage(class, zspage, fg[i]); + remove_zspage(class, zspage); return zspage; } } @@ -1784,18 +1557,14 @@ static struct zspage *isolate_zspage(struct size_class *class, bool source) * @class: destination class * @zspage: target page * - * Return @zspage's fullness_group + * Return @zspage's fullness status */ -static enum fullness_group putback_zspage(struct size_class *class, - struct zspage *zspage) +static int putback_zspage(struct size_class *class, struct zspage *zspage) { - enum fullness_group fullness; - - VM_BUG_ON(is_zspage_isolated(zspage)); + int fullness; fullness = get_fullness_group(class, zspage); insert_zspage(class, zspage, fullness); - set_zspage_mapping(zspage, class->index, fullness); return fullness; } @@ -1807,332 +1576,183 @@ static enum fullness_group putback_zspage(struct size_class *class, */ static void lock_zspage(struct zspage *zspage) { - struct page *page = get_first_page(zspage); - - do { - lock_page(page); - } while ((page = get_next_page(page)) != NULL); -} - -static struct dentry *zs_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, "zsmalloc:", NULL, &ops, ZSMALLOC_MAGIC); -} - -static struct file_system_type zsmalloc_fs = { - .name = "zsmalloc", - .mount = zs_mount, - .kill_sb = kill_anon_super, -}; - -static int zsmalloc_mount(void) -{ - int ret = 0; - - zsmalloc_mnt = kern_mount(&zsmalloc_fs); - if (IS_ERR(zsmalloc_mnt)) - ret = PTR_ERR(zsmalloc_mnt); - - return ret; -} - -static void zsmalloc_unmount(void) -{ - kern_unmount(zsmalloc_mnt); -} + struct zpdesc *curr_zpdesc, *zpdesc; -static void migrate_lock_init(struct zspage *zspage) -{ - rwlock_init(&zspage->lock); -} - -static void migrate_read_lock(struct zspage *zspage) -{ - read_lock(&zspage->lock); -} - -static void migrate_read_unlock(struct zspage *zspage) -{ - read_unlock(&zspage->lock); -} - -static void migrate_write_lock(struct zspage *zspage) -{ - write_lock(&zspage->lock); -} - -static void migrate_write_unlock(struct zspage *zspage) -{ - write_unlock(&zspage->lock); -} + /* + * Pages we haven't locked yet can be migrated off the list while we're + * trying to lock them, so we need to be careful and only attempt to + * lock each page under zspage_read_lock(). Otherwise, the page we lock + * may no longer belong to the zspage. This means that we may wait for + * the wrong page to unlock, so we must take a reference to the page + * prior to waiting for it to unlock outside zspage_read_lock(). + */ + while (1) { + zspage_read_lock(zspage); + zpdesc = get_first_zpdesc(zspage); + if (zpdesc_trylock(zpdesc)) + break; + zpdesc_get(zpdesc); + zspage_read_unlock(zspage); + zpdesc_wait_locked(zpdesc); + zpdesc_put(zpdesc); + } -/* Number of isolated subpage for *page migration* in this zspage */ -static void inc_zspage_isolation(struct zspage *zspage) -{ - zspage->isolated++; + curr_zpdesc = zpdesc; + while ((zpdesc = get_next_zpdesc(curr_zpdesc))) { + if (zpdesc_trylock(zpdesc)) { + curr_zpdesc = zpdesc; + } else { + zpdesc_get(zpdesc); + zspage_read_unlock(zspage); + zpdesc_wait_locked(zpdesc); + zpdesc_put(zpdesc); + zspage_read_lock(zspage); + } + } + zspage_read_unlock(zspage); } +#endif /* CONFIG_COMPACTION */ -static void dec_zspage_isolation(struct zspage *zspage) -{ - zspage->isolated--; -} +#ifdef CONFIG_COMPACTION static void replace_sub_page(struct size_class *class, struct zspage *zspage, - struct page *newpage, struct page *oldpage) + struct zpdesc *newzpdesc, struct zpdesc *oldzpdesc) { - struct page *page; - struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, }; + struct zpdesc *zpdesc; + struct zpdesc *zpdescs[ZS_MAX_PAGES_PER_ZSPAGE] = {NULL, }; + unsigned int first_obj_offset; int idx = 0; - page = get_first_page(zspage); + zpdesc = get_first_zpdesc(zspage); do { - if (page == oldpage) - pages[idx] = newpage; + if (zpdesc == oldzpdesc) + zpdescs[idx] = newzpdesc; else - pages[idx] = page; + zpdescs[idx] = zpdesc; idx++; - } while ((page = get_next_page(page)) != NULL); + } while ((zpdesc = get_next_zpdesc(zpdesc)) != NULL); - create_page_chain(class, zspage, pages); - set_first_obj_offset(newpage, get_first_obj_offset(oldpage)); - if (unlikely(PageHugeObject(oldpage))) - newpage->index = oldpage->index; - __SetPageMovable(newpage, page_mapping(oldpage)); + create_page_chain(class, zspage, zpdescs); + first_obj_offset = get_first_obj_offset(oldzpdesc); + set_first_obj_offset(newzpdesc, first_obj_offset); + if (unlikely(ZsHugePage(zspage))) + newzpdesc->handle = oldzpdesc->handle; + __zpdesc_set_movable(newzpdesc); } static bool zs_page_isolate(struct page *page, isolate_mode_t mode) { - struct zs_pool *pool; - struct size_class *class; - int class_idx; - enum fullness_group fullness; - struct zspage *zspage; - struct address_space *mapping; - /* - * Page is locked so zspage couldn't be destroyed. For detail, look at - * lock_zspage in free_zspage. + * Page is locked so zspage can't be destroyed concurrently + * (see free_zspage()). But if the page was already destroyed + * (see reset_zpdesc()), refuse isolation here. */ - VM_BUG_ON_PAGE(!PageMovable(page), page); - VM_BUG_ON_PAGE(PageIsolated(page), page); - - zspage = get_zspage(page); - - /* - * Without class lock, fullness could be stale while class_idx is okay - * because class_idx is constant unless page is freed so we should get - * fullness again under class lock. - */ - get_zspage_mapping(zspage, &class_idx, &fullness); - mapping = page_mapping(page); - pool = mapping->private_data; - class = pool->size_class[class_idx]; - - spin_lock(&class->lock); - if (get_zspage_inuse(zspage) == 0) { - spin_unlock(&class->lock); - return false; - } - - /* zspage is isolated for object migration */ - if (list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { - spin_unlock(&class->lock); - return false; - } - - /* - * If this is first time isolation for the zspage, isolate zspage from - * size_class to prevent further object allocation from the zspage. - */ - if (!list_empty(&zspage->list) && !is_zspage_isolated(zspage)) { - get_zspage_mapping(zspage, &class_idx, &fullness); - remove_zspage(class, zspage, fullness); - } - - inc_zspage_isolation(zspage); - spin_unlock(&class->lock); - - return true; + return page_zpdesc(page)->zspage; } -static int zs_page_migrate(struct address_space *mapping, struct page *newpage, - struct page *page, enum migrate_mode mode) +static int zs_page_migrate(struct page *newpage, struct page *page, + enum migrate_mode mode) { struct zs_pool *pool; struct size_class *class; - int class_idx; - enum fullness_group fullness; struct zspage *zspage; - struct page *dummy; + struct zpdesc *dummy; + struct zpdesc *newzpdesc = page_zpdesc(newpage); + struct zpdesc *zpdesc = page_zpdesc(page); void *s_addr, *d_addr, *addr; - int offset, pos; - unsigned long handle, head; + unsigned int offset; + unsigned long handle; unsigned long old_obj, new_obj; unsigned int obj_idx; - int ret = -EAGAIN; /* - * We cannot support the _NO_COPY case here, because copy needs to - * happen under the zs lock, which does not work with - * MIGRATE_SYNC_NO_COPY workflow. + * TODO: nothing prevents a zspage from getting destroyed while + * it is isolated for migration, as the page lock is temporarily + * dropped after zs_page_isolate() succeeded: we should rework that + * and defer destroying such pages once they are un-isolated (putback) + * instead. */ - if (mode == MIGRATE_SYNC_NO_COPY) - return -EINVAL; - - VM_BUG_ON_PAGE(!PageMovable(page), page); - VM_BUG_ON_PAGE(!PageIsolated(page), page); + if (!zpdesc->zspage) + return 0; - zspage = get_zspage(page); + /* The page is locked, so this pointer must remain valid */ + zspage = get_zspage(zpdesc); + pool = zspage->pool; - /* Concurrent compactor cannot migrate any subpage in zspage */ - migrate_write_lock(zspage); - get_zspage_mapping(zspage, &class_idx, &fullness); - pool = mapping->private_data; - class = pool->size_class[class_idx]; - offset = get_first_obj_offset(page); + /* + * The pool migrate_lock protects the race between zpage migration + * and zs_free. + */ + write_lock(&pool->lock); + class = zspage_class(pool, zspage); + /* + * the class lock protects zpage alloc/free in the zspage. + */ spin_lock(&class->lock); - if (!get_zspage_inuse(zspage)) { - /* - * Set "offset" to end of the page so that every loops - * skips unnecessary object scanning. - */ - offset = PAGE_SIZE; + /* the zspage write_lock protects zpage access via zs_obj_read/write() */ + if (!zspage_write_trylock(zspage)) { + spin_unlock(&class->lock); + write_unlock(&pool->lock); + return -EINVAL; } - pos = offset; - s_addr = kmap_atomic(page); - while (pos < PAGE_SIZE) { - head = obj_to_head(page, s_addr + pos); - if (head & OBJ_ALLOCATED_TAG) { - handle = head & ~OBJ_ALLOCATED_TAG; - if (!trypin_tag(handle)) - goto unpin_objects; - } - pos += class->size; - } + /* We're committed, tell the world that this is a Zsmalloc page. */ + __zpdesc_set_zsmalloc(newzpdesc); + + offset = get_first_obj_offset(zpdesc); + s_addr = kmap_local_zpdesc(zpdesc); /* * Here, any user cannot access all objects in the zspage so let's move. */ - d_addr = kmap_atomic(newpage); - memcpy(d_addr, s_addr, PAGE_SIZE); - kunmap_atomic(d_addr); + d_addr = kmap_local_zpdesc(newzpdesc); + copy_page(d_addr, s_addr); + kunmap_local(d_addr); - for (addr = s_addr + offset; addr < s_addr + pos; + for (addr = s_addr + offset; addr < s_addr + PAGE_SIZE; addr += class->size) { - head = obj_to_head(page, addr); - if (head & OBJ_ALLOCATED_TAG) { - handle = head & ~OBJ_ALLOCATED_TAG; - if (!testpin_tag(handle)) - BUG(); + if (obj_allocated(zpdesc, addr, &handle)) { old_obj = handle_to_obj(handle); obj_to_location(old_obj, &dummy, &obj_idx); - new_obj = (unsigned long)location_to_obj(newpage, - obj_idx); - new_obj |= BIT(HANDLE_PIN_BIT); + new_obj = (unsigned long)location_to_obj(newzpdesc, obj_idx); record_obj(handle, new_obj); } } + kunmap_local(s_addr); - replace_sub_page(class, zspage, newpage, page); - get_page(newpage); - - dec_zspage_isolation(zspage); - + replace_sub_page(class, zspage, newzpdesc, zpdesc); /* - * Page migration is done so let's putback isolated zspage to - * the list if @page is final isolated subpage in the zspage. + * Since we complete the data copy and set up new zspage structure, + * it's okay to release migration_lock. */ - if (!is_zspage_isolated(zspage)) - putback_zspage(class, zspage); - - reset_page(page); - put_page(page); - page = newpage; - - ret = MIGRATEPAGE_SUCCESS; -unpin_objects: - for (addr = s_addr + offset; addr < s_addr + pos; - addr += class->size) { - head = obj_to_head(page, addr); - if (head & OBJ_ALLOCATED_TAG) { - handle = head & ~OBJ_ALLOCATED_TAG; - if (!testpin_tag(handle)) - BUG(); - unpin_tag(handle); - } - } - kunmap_atomic(s_addr); + write_unlock(&pool->lock); spin_unlock(&class->lock); - migrate_write_unlock(zspage); + zspage_write_unlock(zspage); - return ret; + zpdesc_get(newzpdesc); + if (zpdesc_zone(newzpdesc) != zpdesc_zone(zpdesc)) { + zpdesc_dec_zone_page_state(zpdesc); + zpdesc_inc_zone_page_state(newzpdesc); + } + + reset_zpdesc(zpdesc); + zpdesc_put(zpdesc); + + return 0; } static void zs_page_putback(struct page *page) { - struct zs_pool *pool; - struct size_class *class; - int class_idx; - enum fullness_group fg; - struct address_space *mapping; - struct zspage *zspage; - - VM_BUG_ON_PAGE(!PageMovable(page), page); - VM_BUG_ON_PAGE(!PageIsolated(page), page); - - zspage = get_zspage(page); - get_zspage_mapping(zspage, &class_idx, &fg); - mapping = page_mapping(page); - pool = mapping->private_data; - class = pool->size_class[class_idx]; - - spin_lock(&class->lock); - dec_zspage_isolation(zspage); - if (!is_zspage_isolated(zspage)) { - fg = putback_zspage(class, zspage); - /* - * Due to page_lock, we cannot free zspage immediately - * so let's defer. - */ - if (fg == ZS_EMPTY) - schedule_work(&pool->free_work); - } - spin_unlock(&class->lock); } -static const struct address_space_operations zsmalloc_aops = { +const struct movable_operations zsmalloc_mops = { .isolate_page = zs_page_isolate, - .migratepage = zs_page_migrate, + .migrate_page = zs_page_migrate, .putback_page = zs_page_putback, }; -static int zs_register_migration(struct zs_pool *pool) -{ - pool->inode = alloc_anon_inode(zsmalloc_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 = &zsmalloc_aops; - return 0; -} - -static void zs_unregister_migration(struct zs_pool *pool) -{ - flush_work(&pool->free_work); - iput(pool->inode); -} - /* * Caller should hold page_lock of all pages in the zspage * In here, we cannot use zspage meta data. @@ -2141,8 +1761,6 @@ static void async_free_zspage(struct work_struct *work) { int i; struct size_class *class; - unsigned int class_idx; - enum fullness_group fullness; struct zspage *zspage, *tmp; LIST_HEAD(free_pages); struct zs_pool *pool = container_of(work, struct zs_pool, @@ -2154,20 +1772,19 @@ static void async_free_zspage(struct work_struct *work) continue; spin_lock(&class->lock); - list_splice_init(&class->fullness_list[ZS_EMPTY], &free_pages); + list_splice_init(&class->fullness_list[ZS_INUSE_RATIO_0], + &free_pages); spin_unlock(&class->lock); } - list_for_each_entry_safe(zspage, tmp, &free_pages, list) { list_del(&zspage->list); lock_zspage(zspage); - get_zspage_mapping(zspage, &class_idx, &fullness); - VM_BUG_ON(fullness != ZS_EMPTY); - class = pool->size_class[class_idx]; + class = zspage_class(pool, zspage); spin_lock(&class->lock); - __free_zspage(pool, pool->size_class[class_idx], zspage); + class_stat_sub(class, ZS_INUSE_RATIO_0, 1); + __free_zspage(pool, class, zspage); spin_unlock(&class->lock); } }; @@ -2177,6 +1794,11 @@ static void kick_deferred_free(struct zs_pool *pool) schedule_work(&pool->free_work); } +static void zs_flush_migration(struct zs_pool *pool) +{ + flush_work(&pool->free_work); +} + static void init_deferred_free(struct zs_pool *pool) { INIT_WORK(&pool->free_work, async_free_zspage); @@ -2184,14 +1806,16 @@ static void init_deferred_free(struct zs_pool *pool) static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) { - struct page *page = get_first_page(zspage); + struct zpdesc *zpdesc = get_first_zpdesc(zspage); do { - WARN_ON(!trylock_page(page)); - __SetPageMovable(page, pool->inode->i_mapping); - unlock_page(page); - } while ((page = get_next_page(page)) != NULL); + WARN_ON(!zpdesc_trylock(zpdesc)); + __zpdesc_set_movable(zpdesc); + zpdesc_unlock(zpdesc); + } while ((zpdesc = get_next_zpdesc(zpdesc)) != NULL); } +#else +static inline void zs_flush_migration(struct zs_pool *pool) { } #endif /* @@ -2202,8 +1826,8 @@ static void SetZsPageMovable(struct zs_pool *pool, struct zspage *zspage) static unsigned long zs_can_compact(struct size_class *class) { unsigned long obj_wasted; - unsigned long obj_allocated = zs_stat_get(class, OBJ_ALLOCATED); - unsigned long obj_used = zs_stat_get(class, OBJ_USED); + unsigned long obj_allocated = class_stat_read(class, ZS_OBJS_ALLOCATED); + unsigned long obj_used = class_stat_read(class, ZS_OBJS_INUSE); if (obj_allocated <= obj_used) return 0; @@ -2214,68 +1838,95 @@ static unsigned long zs_can_compact(struct size_class *class) return obj_wasted * class->pages_per_zspage; } -static void __zs_compact(struct zs_pool *pool, struct size_class *class) +static unsigned long __zs_compact(struct zs_pool *pool, + struct size_class *class) { - struct zs_compact_control cc; - struct zspage *src_zspage; + struct zspage *src_zspage = NULL; struct zspage *dst_zspage = NULL; + unsigned long pages_freed = 0; + /* + * protect the race between zpage migration and zs_free + * as well as zpage allocation/free + */ + write_lock(&pool->lock); spin_lock(&class->lock); - while ((src_zspage = isolate_zspage(class, true))) { + while (zs_can_compact(class)) { + int fg; - if (!zs_can_compact(class)) + if (!dst_zspage) { + dst_zspage = isolate_dst_zspage(class); + if (!dst_zspage) + break; + } + + src_zspage = isolate_src_zspage(class); + if (!src_zspage) break; - cc.obj_idx = 0; - cc.s_page = get_first_page(src_zspage); + if (!zspage_write_trylock(src_zspage)) + break; - while ((dst_zspage = isolate_zspage(class, false))) { - cc.d_page = get_first_page(dst_zspage); - /* - * If there is no more space in dst_page, resched - * and see if anyone had allocated another zspage. - */ - if (!migrate_zspage(pool, class, &cc)) - break; + migrate_zspage(pool, src_zspage, dst_zspage); + zspage_write_unlock(src_zspage); - putback_zspage(class, dst_zspage); + fg = putback_zspage(class, src_zspage); + if (fg == ZS_INUSE_RATIO_0) { + free_zspage(pool, class, src_zspage); + pages_freed += class->pages_per_zspage; } + src_zspage = NULL; - /* Stop if we couldn't find slot */ - if (dst_zspage == NULL) - break; + if (get_fullness_group(class, dst_zspage) == ZS_INUSE_RATIO_100 + || rwlock_is_contended(&pool->lock)) { + putback_zspage(class, dst_zspage); + dst_zspage = NULL; - putback_zspage(class, dst_zspage); - if (putback_zspage(class, src_zspage) == ZS_EMPTY) { - free_zspage(pool, class, src_zspage); - pool->stats.pages_compacted += class->pages_per_zspage; + spin_unlock(&class->lock); + write_unlock(&pool->lock); + cond_resched(); + write_lock(&pool->lock); + spin_lock(&class->lock); } - spin_unlock(&class->lock); - cond_resched(); - spin_lock(&class->lock); } if (src_zspage) putback_zspage(class, src_zspage); + if (dst_zspage) + putback_zspage(class, dst_zspage); + spin_unlock(&class->lock); + write_unlock(&pool->lock); + + return pages_freed; } unsigned long zs_compact(struct zs_pool *pool) { int i; struct size_class *class; + unsigned long pages_freed = 0; + + /* + * Pool compaction is performed under pool->lock so it is basically + * single-threaded. Having more than one thread in __zs_compact() + * will increase pool->lock contention, which will impact other + * zsmalloc operations that need pool->lock. + */ + if (atomic_xchg(&pool->compaction_in_progress, 1)) + return 0; for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) { class = pool->size_class[i]; - if (!class) - continue; if (class->index != i) continue; - __zs_compact(pool, class); + pages_freed += __zs_compact(pool, class); } + atomic_long_add(pages_freed, &pool->stats.pages_compacted); + atomic_set(&pool->compaction_in_progress, 0); - return pool->stats.pages_compacted; + return pages_freed; } EXPORT_SYMBOL_GPL(zs_compact); @@ -2289,16 +1940,14 @@ static unsigned long zs_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) { unsigned long pages_freed; - struct zs_pool *pool = container_of(shrinker, struct zs_pool, - shrinker); + struct zs_pool *pool = shrinker->private_data; - pages_freed = pool->stats.pages_compacted; /* * Compact classes and calculate compaction delta. * Can run concurrently with a manually triggered * (by user) compaction. */ - pages_freed = zs_compact(pool) - pages_freed; + pages_freed = zs_compact(pool); return pages_freed ? pages_freed : SHRINK_STOP; } @@ -2309,13 +1958,10 @@ static unsigned long zs_shrinker_count(struct shrinker *shrinker, int i; struct size_class *class; unsigned long pages_to_free = 0; - struct zs_pool *pool = container_of(shrinker, struct zs_pool, - shrinker); + struct zs_pool *pool = shrinker->private_data; for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) { class = pool->size_class[i]; - if (!class) - continue; if (class->index != i) continue; @@ -2327,17 +1973,44 @@ static unsigned long zs_shrinker_count(struct shrinker *shrinker, static void zs_unregister_shrinker(struct zs_pool *pool) { - unregister_shrinker(&pool->shrinker); + shrinker_free(pool->shrinker); } static int zs_register_shrinker(struct zs_pool *pool) { - pool->shrinker.scan_objects = zs_shrinker_scan; - pool->shrinker.count_objects = zs_shrinker_count; - pool->shrinker.batch = 0; - pool->shrinker.seeks = DEFAULT_SEEKS; + pool->shrinker = shrinker_alloc(0, "mm-zspool:%s", pool->name); + if (!pool->shrinker) + return -ENOMEM; + + pool->shrinker->scan_objects = zs_shrinker_scan; + pool->shrinker->count_objects = zs_shrinker_count; + pool->shrinker->batch = 0; + pool->shrinker->private_data = pool; + + shrinker_register(pool->shrinker); + + return 0; +} + +static int calculate_zspage_chain_size(int class_size) +{ + int i, min_waste = INT_MAX; + int chain_size = 1; + + if (is_power_of_2(class_size)) + return chain_size; + + for (i = 1; i <= ZS_MAX_PAGES_PER_ZSPAGE; i++) { + int waste; + + waste = (i * PAGE_SIZE) % class_size; + if (waste < min_waste) { + min_waste = waste; + chain_size = i; + } + } - return register_shrinker(&pool->shrinker); + return chain_size; } /** @@ -2361,6 +2034,8 @@ struct zs_pool *zs_create_pool(const char *name) return NULL; init_deferred_free(pool); + rwlock_init(&pool->lock); + atomic_set(&pool->compaction_in_progress, 0); pool->name = kstrdup(name, GFP_KERNEL); if (!pool->name) @@ -2378,12 +2053,12 @@ struct zs_pool *zs_create_pool(const char *name) int pages_per_zspage; int objs_per_zspage; struct size_class *class; - int fullness = 0; + int fullness; size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA; if (size > ZS_MAX_ALLOC_SIZE) size = ZS_MAX_ALLOC_SIZE; - pages_per_zspage = get_pages_per_zspage(size); + pages_per_zspage = calculate_zspage_chain_size(size); objs_per_zspage = pages_per_zspage * PAGE_SIZE / size; /* @@ -2433,9 +2108,12 @@ struct zs_pool *zs_create_pool(const char *name) class->objs_per_zspage = objs_per_zspage; spin_lock_init(&class->lock); pool->size_class[i] = class; - for (fullness = ZS_EMPTY; fullness < NR_ZS_FULLNESS; - fullness++) + + fullness = ZS_INUSE_RATIO_0; + while (fullness < NR_FULLNESS_GROUPS) { INIT_LIST_HEAD(&class->fullness_list[fullness]); + fullness++; + } prev_class = class; } @@ -2443,9 +2121,6 @@ struct zs_pool *zs_create_pool(const char *name) /* debug only, don't abort if it fails */ zs_pool_stat_create(pool, name); - if (zs_register_migration(pool)) - goto err; - /* * Not critical since shrinker is only used to trigger internal * defragmentation of the pool which is pretty optional thing. If @@ -2467,7 +2142,7 @@ void zs_destroy_pool(struct zs_pool *pool) int i; zs_unregister_shrinker(pool); - zs_unregister_migration(pool); + zs_flush_migration(pool); zs_pool_stat_destroy(pool); for (i = 0; i < ZS_SIZE_CLASSES; i++) { @@ -2480,11 +2155,12 @@ void zs_destroy_pool(struct zs_pool *pool) if (class->index != i) continue; - for (fg = ZS_EMPTY; fg < NR_ZS_FULLNESS; fg++) { - if (!list_empty(&class->fullness_list[fg])) { - pr_info("Freeing non-empty class with size %db, fullness group %d\n", - class->size, fg); - } + for (fg = ZS_INUSE_RATIO_0; fg < NR_FULLNESS_GROUPS; fg++) { + if (list_empty(&class->fullness_list[fg])) + continue; + + pr_err("Class-%d fullness group %d is not empty\n", + class->size, fg); } kfree(class); } @@ -2497,39 +2173,22 @@ EXPORT_SYMBOL_GPL(zs_destroy_pool); static int __init zs_init(void) { - int ret; - - ret = zsmalloc_mount(); - if (ret) - goto out; + int rc __maybe_unused; - ret = cpuhp_setup_state(CPUHP_MM_ZS_PREPARE, "mm/zsmalloc:prepare", - zs_cpu_prepare, zs_cpu_dead); - if (ret) - goto hp_setup_fail; - -#ifdef CONFIG_ZPOOL - zpool_register_driver(&zs_zpool_driver); +#ifdef CONFIG_COMPACTION + rc = set_movable_ops(&zsmalloc_mops, PGTY_zsmalloc); + if (rc) + return rc; #endif - zs_stat_init(); - return 0; - -hp_setup_fail: - zsmalloc_unmount(); -out: - return ret; } static void __exit zs_exit(void) { -#ifdef CONFIG_ZPOOL - zpool_unregister_driver(&zs_zpool_driver); +#ifdef CONFIG_COMPACTION + set_movable_ops(NULL, PGTY_zsmalloc); #endif - zsmalloc_unmount(); - cpuhp_remove_state(CPUHP_MM_ZS_PREPARE); - zs_stat_exit(); } @@ -2538,3 +2197,4 @@ module_exit(zs_exit); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Nitin Gupta <ngupta@vflare.org>"); +MODULE_DESCRIPTION("zsmalloc memory allocator"); |