From 25b48b4cdf912f70998336b861a4bf767ee3d332 Mon Sep 17 00:00:00 2001 From: "David Hildenbrand (Red Hat)" Date: Tue, 20 Jan 2026 00:01:28 +0100 Subject: mm: rename balloon_compaction.(c|h) to balloon.(c|h) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Even without CONFIG_BALLOON_COMPACTION this infrastructure implements basic list and page management for a memory balloon. Link: https://lkml.kernel.org/r/20260119230133.3551867-21-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) Reviewed-by: Lorenzo Stoakes Acked-by: Michael S. Tsirkin Cc: Arnd Bergmann Cc: Christophe Leroy Cc: Eugenio Pérez Cc: Greg Kroah-Hartman Cc: Jason Wang Cc: Jerrin Shaji George Cc: Jonathan Corbet Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oscar Salvador Cc: SeongJae Park Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: Zi Yan Signed-off-by: Andrew Morton --- include/linux/balloon.h | 77 +++++++++++++++++++++++++++++++++++++ include/linux/balloon_compaction.h | 78 -------------------------------------- 2 files changed, 77 insertions(+), 78 deletions(-) create mode 100644 include/linux/balloon.h delete mode 100644 include/linux/balloon_compaction.h (limited to 'include') diff --git a/include/linux/balloon.h b/include/linux/balloon.h new file mode 100644 index 000000000000..82585542300d --- /dev/null +++ b/include/linux/balloon.h @@ -0,0 +1,77 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Common interface for implementing a memory balloon, including support + * for migration of pages inflated in a memory balloon. + * + * 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()). + * + * Once the page type and the PG_movable_ops are set, migration code + * can initiate page isolation by invoking the + * movable_operations()->isolate_page() callback + * + * As long as page->private is set, the page is either on the balloon list + * or isolated for migration. If page->private is not set, the page is + * either still getting inflated, or was deflated to be freed by the balloon + * driver soon. Isolation is impossible in both cases. + * + * 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. Inflation/deflation must set/clear page->private under the + * balloon_pages_lock + * + * ii. isolation or dequeueing procedure must remove the page from balloon + * device page list under balloon_pages_lock + * + * Copyright (C) 2012, Red Hat, Inc. Rafael Aquini + */ +#ifndef _LINUX_BALLOON_H +#define _LINUX_BALLOON_H +#include +#include +#include +#include +#include +#include + +/* + * 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 */ + 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); + bool adjust_managed_page_count; +}; + +struct page *balloon_page_alloc(void); +void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, + struct page *page); +struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info); +size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, + struct list_head *pages); +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; + INIT_LIST_HEAD(&balloon->pages); + balloon->migratepage = NULL; + balloon->adjust_managed_page_count = false; +} +#endif /* _LINUX_BALLOON_H */ diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h deleted file mode 100644 index 7757e0e314fd..000000000000 --- a/include/linux/balloon_compaction.h +++ /dev/null @@ -1,78 +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()). - * - * Once the page type and the PG_movable_ops are set, migration code - * can initiate page isolation by invoking the - * movable_operations()->isolate_page() callback - * - * As long as page->private is set, the page is either on the balloon list - * or isolated for migration. If page->private is not set, the page is - * either still getting inflated, or was deflated to be freed by the balloon - * driver soon. Isolation is impossible in both cases. - * - * 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. Inflation/deflation must set/clear page->private under the - * balloon_pages_lock - * - * ii. isolation or dequeueing procedure must remove the page from balloon - * device page list under balloon_pages_lock - * - * Copyright (C) 2012, Red Hat, Inc. Rafael Aquini - */ -#ifndef _LINUX_BALLOON_COMPACTION_H -#define _LINUX_BALLOON_COMPACTION_H -#include -#include -#include -#include -#include -#include - -/* - * 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 */ - 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); - bool adjust_managed_page_count; -}; - -struct page *balloon_page_alloc(void); -void balloon_page_enqueue(struct balloon_dev_info *b_dev_info, - struct page *page); -struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info); -size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info, - struct list_head *pages); -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; - INIT_LIST_HEAD(&balloon->pages); - balloon->migratepage = NULL; - balloon->adjust_managed_page_count = false; -} -#endif /* _LINUX_BALLOON_COMPACTION_H */ -- cgit v1.2.3