The idea of this patch is same with prev version [1]. But it use the migration frame in [1].
[1] http://comments.gmane.org/gmane.linux.kernel.mm/140014 [2] https://lkml.org/lkml/2015/7/7/21 Signed-off-by: Hui Zhu <zhu...@xiaomi.com> --- mm/zsmalloc.c | 214 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 209 insertions(+), 5 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 57c91a5..5034aac 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -53,10 +53,13 @@ #include <linux/vmalloc.h> #include <linux/hardirq.h> #include <linux/spinlock.h> +#include <linux/rwlock.h> #include <linux/types.h> #include <linux/debugfs.h> #include <linux/zsmalloc.h> #include <linux/zpool.h> +#include <linux/migrate.h> +#include <linux/anon_inodes.h> /* * This must be power of 2 and greater than of equal to sizeof(link_free). @@ -217,6 +220,8 @@ struct size_class { /* huge object: pages_per_zspage == 1 && maxobj_per_zspage == 1 */ bool huge; + + atomic_t count; }; /* @@ -281,6 +286,10 @@ struct zs_migration { #define ZS_MIGRATION(p) ((struct zs_migration *)((p)->freelist)) #define ZS_META(p) ((struct zs_meta *)&(ZS_MIGRATION(p)->index)) +static struct inode *zs_inode; +static DEFINE_SPINLOCK(zs_migration_lock); +static DEFINE_RWLOCK(zs_tag_rwlock); + struct mapping_area { #ifdef CONFIG_PGTABLE_MAPPING struct vm_struct *vm; /* vm area for mapping object that span pages */ @@ -307,7 +316,7 @@ static void destroy_handle_cache(struct zs_pool *pool) static unsigned long alloc_handle(struct zs_pool *pool) { return (unsigned long)kmem_cache_alloc(pool->handle_cachep, - pool->flags & ~__GFP_HIGHMEM); + pool->flags & ~(__GFP_HIGHMEM | __GFP_MOVABLE)); } static void free_handle(struct zs_pool *pool, unsigned long handle) @@ -914,9 +923,12 @@ static void reset_page(struct page *page) clear_bit(PG_private, &page->flags); clear_bit(PG_private_2, &page->flags); set_page_private(page, 0); - free_migration(page->freelist); - page->freelist = NULL; + if (page->freelist) { + free_migration(page->freelist); + page->freelist = NULL; + } page_mapcount_reset(page); + page->mapping = NULL; } static void free_zspage(struct page *first_page) @@ -927,6 +939,8 @@ static void free_zspage(struct page *first_page) BUG_ON(!is_first_page(first_page)); BUG_ON(get_inuse_obj(first_page)); + spin_lock(&zs_migration_lock); + head_extra = (struct page *)page_private(first_page); reset_page(first_page); @@ -934,7 +948,7 @@ static void free_zspage(struct page *first_page) /* zspage with only 1 system page */ if (!head_extra) - return; + goto out; list_for_each_entry_safe(nextm, tmp, &ZS_MIGRATION(head_extra)->lru, lru) { @@ -945,6 +959,9 @@ static void free_zspage(struct page *first_page) } reset_page(head_extra); __free_page(head_extra); + +out: + spin_unlock(&zs_migration_lock); } /* Initialize a newly allocated zspage */ @@ -1018,6 +1035,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) page = alloc_page(flags); if (!page) goto cleanup; + page->mapping = zs_inode->i_mapping; page->freelist = alloc_migration(flags); if (!page->freelist) { __free_page(page); @@ -1327,6 +1345,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle, BUG_ON(in_interrupt()); /* From now on, migration cannot move the object */ + read_lock(&zs_tag_rwlock); pin_tag(handle); obj = handle_to_obj(handle); @@ -1395,6 +1414,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle) } put_cpu_var(zs_map_area); unpin_tag(handle); + read_unlock(&zs_tag_rwlock); } EXPORT_SYMBOL_GPL(zs_unmap_object); @@ -1431,6 +1451,16 @@ static unsigned long obj_malloc(struct page *first_page, } +static void set_zspage_mobile(struct size_class *class, struct page *page) +{ + BUG_ON(!is_first_page(page)); + + while (page) { + __SetPageMobile(page); + page = get_next_page(page); + } +} + /** * zs_malloc - Allocate block of given size from pool. * @pool: pool to allocate from @@ -1474,6 +1504,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size) &pool->pages_allocated); spin_lock(&class->lock); + set_zspage_mobile(class, first_page); zs_stat_inc(class, OBJ_ALLOCATED, get_maxobj_per_zspage( class->size, class->pages_per_zspage)); } @@ -1526,6 +1557,7 @@ void zs_free(struct zs_pool *pool, unsigned long handle) if (unlikely(!handle)) return; + read_lock(&zs_tag_rwlock); pin_tag(handle); obj = handle_to_obj(handle); @@ -1546,6 +1578,7 @@ void zs_free(struct zs_pool *pool, unsigned long handle) } spin_unlock(&class->lock); unpin_tag(handle); + read_unlock(&zs_tag_rwlock); free_handle(pool, handle); } @@ -1919,6 +1952,19 @@ static int zs_register_shrinker(struct zs_pool *pool) return register_shrinker(&pool->shrinker); } +static void +get_class(struct size_class *class) +{ + atomic_inc(&class->count); +} + +static void +put_class(struct size_class *class) +{ + if (atomic_dec_and_test(&class->count)) + kfree(class); +} + /** * zs_create_pool - Creates an allocation pool to work from. * @flags: allocation flags used to allocate pool metadata @@ -1995,6 +2041,8 @@ struct zs_pool *zs_create_pool(char *name, gfp_t flags) get_maxobj_per_zspage(size, pages_per_zspage) == 1) class->huge = true; spin_lock_init(&class->lock); + atomic_set(&class->count, 0); + get_class(class); pool->size_class[i] = class; prev_class = class; @@ -2042,7 +2090,9 @@ void zs_destroy_pool(struct zs_pool *pool) class->size, fg); } } - kfree(class); + spin_lock(&zs_migration_lock); + put_class(class); + spin_unlock(&zs_migration_lock); } destroy_handle_cache(pool); @@ -2052,6 +2102,151 @@ void zs_destroy_pool(struct zs_pool *pool) } EXPORT_SYMBOL_GPL(zs_destroy_pool); +bool zs_isolatepage(struct page *page, isolate_mode_t mode) +{ + bool ret = false; + + spin_lock(&zs_migration_lock); + + if (!get_page_unless_zero(page)) + /* The zspage is released. */ + goto out; + if (page_count(page) != 2) + /* The page is isolated by others or just freed. */ + goto put_out; + if (page->freelist == NULL) + goto put_out; + + ret = true; +out: + spin_unlock(&zs_migration_lock); + return ret; + +put_out: + put_page(page); + goto out; +} + +void zs_putbackpage(struct page *page) +{ + put_page(page); +} + +int +zs_migratepage(struct address_space *mapping, + struct page *newpage, struct page *page, + enum migrate_mode mode) +{ + int ret = -EAGAIN; + struct size_class *class; + struct page *first_page; + + /* Get class. */ + spin_lock(&zs_migration_lock); + if (page->freelist == NULL || page_count(page) <= 1) { + spin_unlock(&zs_migration_lock); + return ret; + } + class = ZS_MIGRATION(page)->class; + get_class(class); + spin_unlock(&zs_migration_lock); + + write_lock(&zs_tag_rwlock); + spin_lock(&class->lock); + + if (page->freelist == NULL || page_count(page) <= 1) + goto out; /* The zspage is released. */ + + first_page = get_first_page(page); + + INIT_LIST_HEAD(&ZS_MIGRATION(newpage)->lru); + newpage->mapping = zs_inode->i_mapping; + if (page == first_page) { /* first page */ + struct page **head; + + SetPagePrivate(newpage); + + if (class->huge) { + unsigned long handle = page_private(page); + + if (handle != 0) { + void *addr, *newaddr; + unsigned long obj = obj_idx_to_obj(newpage, 0); + + /* The page is allocated. */ + handle = handle & ~OBJ_ALLOCATED_TAG; + record_obj(handle, obj); + addr = kmap_atomic(page); + newaddr = kmap_atomic(newpage); + memcpy(newaddr, addr, class->size); + kunmap_atomic(newaddr); + kunmap_atomic(addr); + } else + set_free_obj_idx(first_page, 0); + set_page_private(newpage, handle); + } else { + struct page *tmp_page = get_next_page(page); + + while (tmp_page) { + tmp_page->first_page = newpage; + tmp_page = get_next_page(tmp_page); + } + set_page_private(newpage, page_private(page)); + } + + head = &class->fullness_list[ZS_META(first_page)->fullness]; + BUG_ON(!*head); + if (*head == page) + *head = newpage; + } else + newpage->first_page = page->first_page; + + if (is_last_page(page)) /* last page */ + SetPagePrivate2(newpage); + + if (!class->huge) { + void *addr, *newaddr; + + addr = kmap_atomic(page); + newaddr = kmap_atomic(newpage); + copy_page(newaddr, addr); + kunmap_atomic(newaddr); + kunmap_atomic(addr); + } + + /* Add newpage to zspage. */ + if (first_page == page) + first_page = newpage; + else { + if ((struct page *)page_private(first_page) == page) + set_page_private(first_page, (unsigned long)newpage); + } + newpage->freelist = page->freelist; + ZS_MIGRATION(newpage)->page = newpage; + + get_page(newpage); + __SetPageMobile(newpage); + + spin_lock(&zs_migration_lock); + page->freelist = NULL; + reset_page(page); + put_page(page); + spin_unlock(&zs_migration_lock); + + ret = MIGRATEPAGE_SUCCESS; +out: + spin_unlock(&class->lock); + write_unlock(&zs_tag_rwlock); + put_class(class); + return ret; +} + +const struct address_space_operations zs_mobile_aops = { + .migratepage = zs_migratepage, + .isolatepage = zs_isolatepage, + .putbackpage = zs_putbackpage, +}; + static int __init zs_init(void) { int ret = zs_register_cpu_notifier(); @@ -2082,6 +2277,13 @@ static int __init zs_init(void) goto stat_fail; } + zs_inode = anon_inode_new(); + if (IS_ERR(zs_inode)) { + pr_err("zs inode initialization failed\n"); + ret = PTR_ERR(zs_inode); + } + zs_inode->i_mapping->a_ops = &zs_mobile_aops; + return 0; stat_fail: @@ -2096,6 +2298,8 @@ notifier_fail: static void __exit zs_exit(void) { + iput(zs_inode); + kmem_cache_destroy(zs_migration_cachep); #ifdef CONFIG_ZPOOL -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
