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Diffstat (limited to 'include/linux/balloon_compaction.h')
| -rw-r--r-- | include/linux/balloon_compaction.h | 160 |
1 files changed, 0 insertions, 160 deletions
diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h deleted file mode 100644 index 7cfe48769239..000000000000 --- a/include/linux/balloon_compaction.h +++ /dev/null @@ -1,160 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * include/linux/balloon_compaction.h - * - * Common interface definitions for making balloon pages movable by compaction. - * - * Balloon page migration makes use of the general "movable_ops page migration" - * feature. - * - * page->private is used to reference the responsible balloon device. - * That these pages have movable_ops, and which movable_ops apply, - * is derived from the page type (PageOffline()) combined with the - * PG_movable_ops flag (PageMovableOps()). - * - * As the page isolation scanning step a compaction thread does is a lockless - * procedure (from a page standpoint), it might bring some racy situations while - * performing balloon page compaction. In order to sort out these racy scenarios - * and safely perform balloon's page compaction and migration we must, always, - * ensure following these simple rules: - * - * i. Setting the PG_movable_ops flag and page->private with the following - * lock order - * +-page_lock(page); - * +--spin_lock_irq(&b_dev_info->pages_lock); - * - * ii. isolation or dequeueing procedure must remove the page from balloon - * device page list under b_dev_info->pages_lock. - * - * The functions provided by this interface are placed to help on coping with - * the aforementioned balloon page corner case, as well as to ensure the simple - * set of exposed rules are satisfied while we are dealing with balloon pages - * compaction / migration. - * - * Copyright (C) 2012, Red Hat, Inc. Rafael Aquini <aquini@redhat.com> - */ -#ifndef _LINUX_BALLOON_COMPACTION_H -#define _LINUX_BALLOON_COMPACTION_H -#include <linux/pagemap.h> -#include <linux/page-flags.h> -#include <linux/migrate.h> -#include <linux/gfp.h> -#include <linux/err.h> -#include <linux/fs.h> -#include <linux/list.h> - -/* - * Balloon device information descriptor. - * This struct is used to allow the common balloon compaction interface - * procedures to find the proper balloon device holding memory pages they'll - * have to cope for page compaction / migration, as well as it serves the - * balloon driver as a page book-keeper for its registered balloon devices. - */ -struct balloon_dev_info { - unsigned long isolated_pages; /* # of isolated pages for migration */ - spinlock_t pages_lock; /* Protection to pages list */ - struct list_head pages; /* Pages enqueued & handled to Host */ - int (*migratepage)(struct balloon_dev_info *, struct page *newpage, - struct page *page, enum migrate_mode mode); -}; - -extern struct page *balloon_page_alloc(void); -extern void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, - struct page *page); -extern struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info); -extern size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, - struct list_head *pages); -extern size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info, - struct list_head *pages, size_t n_req_pages); - -static inline void balloon_devinfo_init(struct balloon_dev_info *balloon) -{ - balloon->isolated_pages = 0; - spin_lock_init(&balloon->pages_lock); - INIT_LIST_HEAD(&balloon->pages); - balloon->migratepage = NULL; -} - -#ifdef CONFIG_BALLOON_COMPACTION -extern const struct movable_operations balloon_mops; -/* - * balloon_page_device - get the b_dev_info descriptor for the balloon device - * that enqueues the given page. - */ -static inline struct balloon_dev_info *balloon_page_device(struct page *page) -{ - return (struct balloon_dev_info *)page_private(page); -} -#endif /* CONFIG_BALLOON_COMPACTION */ - -/* - * balloon_page_insert - insert a page into the balloon's page list and make - * the page->private assignment accordingly. - * @balloon : pointer to balloon device - * @page : page to be assigned as a 'balloon page' - * - * Caller must ensure the page is locked and the spin_lock protecting balloon - * pages list is held before inserting a page into the balloon device. - */ -static inline void balloon_page_insert(struct balloon_dev_info *balloon, - struct page *page) -{ - __SetPageOffline(page); - if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) { - SetPageMovableOps(page); - set_page_private(page, (unsigned long)balloon); - } - list_add(&page->lru, &balloon->pages); -} - -static inline gfp_t balloon_mapping_gfp_mask(void) -{ - if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) - return GFP_HIGHUSER_MOVABLE; - return GFP_HIGHUSER; -} - -/* - * balloon_page_finalize - prepare a balloon page that was removed from the - * balloon list for release to the page allocator - * @page: page to be released to the page allocator - * - * Caller must ensure that the page is locked. - */ -static inline void balloon_page_finalize(struct page *page) -{ - if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) - set_page_private(page, 0); - /* PageOffline is sticky until the page is freed to the buddy. */ -} - -/* - * balloon_page_push - insert a page into a page list. - * @head : pointer to list - * @page : page to be added - * - * Caller must ensure the page is private and protect the list. - */ -static inline void balloon_page_push(struct list_head *pages, struct page *page) -{ - list_add(&page->lru, pages); -} - -/* - * balloon_page_pop - remove a page from a page list. - * @head : pointer to list - * @page : page to be added - * - * Caller must ensure the page is private and protect the list. - */ -static inline struct page *balloon_page_pop(struct list_head *pages) -{ - struct page *page = list_first_entry_or_null(pages, struct page, lru); - - if (!page) - return NULL; - - list_del(&page->lru); - return page; -} -#endif /* _LINUX_BALLOON_COMPACTION_H */ |