diff options
author | Jiri Kosina <jkosina@suse.cz> | 2014-11-20 16:42:02 +0300 |
---|---|---|
committer | Jiri Kosina <jkosina@suse.cz> | 2014-11-20 16:42:02 +0300 |
commit | a02001086bbfb4da35d1228bebc2f1b442db455f (patch) | |
tree | 62ab47936cef06fd08657ca5b6cd1df98c19be57 /mm/balloon_compaction.c | |
parent | eff264efeeb0898408e8c9df72d8a32621035bed (diff) | |
parent | fc14f9c1272f62c3e8d01300f52467c0d9af50f9 (diff) |
Merge Linus' tree to be be to apply submitted patches to newer code than
current trivial.git base
Diffstat (limited to 'mm/balloon_compaction.c')
-rw-r--r-- | mm/balloon_compaction.c | 125 |
1 files changed, 22 insertions, 103 deletions
diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 6e45a5074bf0..fcad8322ef36 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -11,32 +11,6 @@ #include <linux/balloon_compaction.h> /* - * balloon_devinfo_alloc - allocates a balloon device information descriptor. - * @balloon_dev_descriptor: pointer to reference the balloon device which - * this struct balloon_dev_info will be servicing. - * - * Driver must call it to properly allocate and initialize an instance of - * struct balloon_dev_info which will be used to reference a balloon device - * as well as to keep track of the balloon device page list. - */ -struct balloon_dev_info *balloon_devinfo_alloc(void *balloon_dev_descriptor) -{ - struct balloon_dev_info *b_dev_info; - b_dev_info = kmalloc(sizeof(*b_dev_info), GFP_KERNEL); - if (!b_dev_info) - return ERR_PTR(-ENOMEM); - - b_dev_info->balloon_device = balloon_dev_descriptor; - b_dev_info->mapping = NULL; - b_dev_info->isolated_pages = 0; - spin_lock_init(&b_dev_info->pages_lock); - INIT_LIST_HEAD(&b_dev_info->pages); - - return b_dev_info; -} -EXPORT_SYMBOL_GPL(balloon_devinfo_alloc); - -/* * balloon_page_enqueue - allocates a new page and inserts it into the balloon * page list. * @b_dev_info: balloon device decriptor where we will insert a new page to @@ -61,7 +35,8 @@ struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info) */ BUG_ON(!trylock_page(page)); spin_lock_irqsave(&b_dev_info->pages_lock, flags); - balloon_page_insert(page, b_dev_info->mapping, &b_dev_info->pages); + balloon_page_insert(b_dev_info, page); + __count_vm_event(BALLOON_INFLATE); spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); unlock_page(page); return page; @@ -93,18 +68,16 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) * to be released by the balloon driver. */ if (trylock_page(page)) { +#ifdef CONFIG_BALLOON_COMPACTION + if (!PagePrivate(page)) { + /* raced with isolation */ + unlock_page(page); + continue; + } +#endif spin_lock_irqsave(&b_dev_info->pages_lock, flags); - /* - * Raise the page refcount here to prevent any wrong - * attempt to isolate this page, in case of coliding - * with balloon_page_isolate() just after we release - * the page lock. - * - * balloon_page_free() will take care of dropping - * this extra refcount later. - */ - get_page(page); balloon_page_delete(page); + __count_vm_event(BALLOON_DEFLATE); spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); unlock_page(page); dequeued_page = true; @@ -132,62 +105,14 @@ struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info) EXPORT_SYMBOL_GPL(balloon_page_dequeue); #ifdef CONFIG_BALLOON_COMPACTION -/* - * balloon_mapping_alloc - allocates a special ->mapping for ballooned pages. - * @b_dev_info: holds the balloon device information descriptor. - * @a_ops: balloon_mapping address_space_operations descriptor. - * - * Driver must call it to properly allocate and initialize an instance of - * struct address_space which will be used as the special page->mapping for - * balloon device enlisted page instances. - */ -struct address_space *balloon_mapping_alloc(struct balloon_dev_info *b_dev_info, - const struct address_space_operations *a_ops) -{ - struct address_space *mapping; - - mapping = kmalloc(sizeof(*mapping), GFP_KERNEL); - if (!mapping) - return ERR_PTR(-ENOMEM); - - /* - * Give a clean 'zeroed' status to all elements of this special - * balloon page->mapping struct address_space instance. - */ - address_space_init_once(mapping); - - /* - * Set mapping->flags appropriately, to allow balloon pages - * ->mapping identification. - */ - mapping_set_balloon(mapping); - mapping_set_gfp_mask(mapping, balloon_mapping_gfp_mask()); - - /* balloon's page->mapping->a_ops callback descriptor */ - mapping->a_ops = a_ops; - - /* - * Establish a pointer reference back to the balloon device descriptor - * this particular page->mapping will be servicing. - * This is used by compaction / migration procedures to identify and - * access the balloon device pageset while isolating / migrating pages. - * - * As some balloon drivers can register multiple balloon devices - * for a single guest, this also helps compaction / migration to - * properly deal with multiple balloon pagesets, when required. - */ - mapping->private_data = b_dev_info; - b_dev_info->mapping = mapping; - - return mapping; -} -EXPORT_SYMBOL_GPL(balloon_mapping_alloc); static inline void __isolate_balloon_page(struct page *page) { - struct balloon_dev_info *b_dev_info = page->mapping->private_data; + struct balloon_dev_info *b_dev_info = balloon_page_device(page); unsigned long flags; + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + ClearPagePrivate(page); list_del(&page->lru); b_dev_info->isolated_pages++; spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); @@ -195,20 +120,16 @@ static inline void __isolate_balloon_page(struct page *page) static inline void __putback_balloon_page(struct page *page) { - struct balloon_dev_info *b_dev_info = page->mapping->private_data; + struct balloon_dev_info *b_dev_info = balloon_page_device(page); unsigned long flags; + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + SetPagePrivate(page); list_add(&page->lru, &b_dev_info->pages); b_dev_info->isolated_pages--; spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); } -static inline int __migrate_balloon_page(struct address_space *mapping, - struct page *newpage, struct page *page, enum migrate_mode mode) -{ - return page->mapping->a_ops->migratepage(mapping, newpage, page, mode); -} - /* __isolate_lru_page() counterpart for a ballooned page */ bool balloon_page_isolate(struct page *page) { @@ -235,12 +156,11 @@ bool balloon_page_isolate(struct page *page) */ if (likely(trylock_page(page))) { /* - * A ballooned page, by default, has just one refcount. + * A ballooned page, by default, has PagePrivate set. * Prevent concurrent compaction threads from isolating - * an already isolated balloon page by refcount check. + * an already isolated balloon page by clearing it. */ - if (__is_movable_balloon_page(page) && - page_count(page) == 2) { + if (balloon_page_movable(page)) { __isolate_balloon_page(page); unlock_page(page); return true; @@ -276,7 +196,7 @@ void balloon_page_putback(struct page *page) int balloon_page_migrate(struct page *newpage, struct page *page, enum migrate_mode mode) { - struct address_space *mapping; + struct balloon_dev_info *balloon = balloon_page_device(page); int rc = -EAGAIN; /* @@ -292,9 +212,8 @@ int balloon_page_migrate(struct page *newpage, return rc; } - mapping = page->mapping; - if (mapping) - rc = __migrate_balloon_page(mapping, newpage, page, mode); + if (balloon && balloon->migratepage) + rc = balloon->migratepage(balloon, newpage, page, mode); unlock_page(newpage); return rc; |