disable kernel build waring

hc

2024-05-10 093a6c67005148ae32a5c9e4553491b9f5c2457b

 kernel/include/linux/balloon_compaction.h
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@@ -4,15 +4,18 @@
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  *
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  * Common interface definitions for making balloon pages movable by compaction.
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  *
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- * Despite being perfectly possible to perform ballooned pages migration, they
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- * make a special corner case to compaction scans because balloon pages are not
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- * enlisted at any LRU list like the other pages we do compact / migrate.
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+ * Balloon page migration makes use of the general non-lru movable page
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+ * feature.
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+ *
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+ * page->private is used to reference the responsible balloon device.
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+ * page->mapping is used in context of non-lru page migration to reference
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+ * the address space operations for page isolation/migration/compaction.
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  *
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  * As the page isolation scanning step a compaction thread does is a lockless
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  * procedure (from a page standpoint), it might bring some racy situations while
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  * performing balloon page compaction. In order to sort out these racy scenarios
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  * and safely perform balloon's page compaction and migration we must, always,
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- * ensure following these three simple rules:
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+ * ensure following these simple rules:
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  *
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  *   i. when updating a balloon's page ->mapping element, strictly do it under
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  *      the following lock order, independently of the far superior
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@@ -21,19 +24,8 @@
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  *	      +--spin_lock_irq(&b_dev_info->pages_lock);
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  *	            ... page->mapping updates here ...
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  *
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- *  ii. before isolating or dequeueing a balloon page from the balloon device
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- *      pages list, the page reference counter must be raised by one and the
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- *      extra refcount must be dropped when the page is enqueued back into
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- *      the balloon device page list, thus a balloon page keeps its reference
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- *      counter raised only while it is under our special handling;
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- *
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- * iii. after the lockless scan step have selected a potential balloon page for
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- *      isolation, re-test the PageBalloon mark and the PagePrivate flag
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- *      under the proper page lock, to ensure isolating a valid balloon page
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- *      (not yet isolated, nor under release procedure)
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- *
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- *  iv. isolation or dequeueing procedure must clear PagePrivate flag under
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- *      page lock together with removing page from balloon device page list.
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+ *  ii. isolation or dequeueing procedure must remove the page from balloon
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+ *      device page list under b_dev_info->pages_lock.
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  *
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  * The functions provided by this interface are placed to help on coping with
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  * the aforementioned balloon page corner case, as well as to ensure the simple
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@@ -72,6 +64,10 @@
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 extern void balloon_page_enqueue(struct balloon_dev_info *b_dev_info,
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 				 struct page *page);
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 extern struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info);
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+extern size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info,
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+				      struct list_head *pages);
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+extern size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
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+				     struct list_head *pages, size_t n_req_pages);
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 static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
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 {
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@@ -103,7 +99,7 @@
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 static inline void balloon_page_insert(struct balloon_dev_info *balloon,
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 				       struct page *page)
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 {
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-	__SetPageBalloon(page);
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+	__SetPageOffline(page);
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 	__SetPageMovable(page, balloon->inode->i_mapping);
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 	set_page_private(page, (unsigned long)balloon);
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 	list_add(&page->lru, &balloon->pages);
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@@ -119,7 +115,7 @@
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  */
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 static inline void balloon_page_delete(struct page *page)
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 {
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-	__ClearPageBalloon(page);
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+	__ClearPageOffline(page);
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 	__ClearPageMovable(page);
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 	set_page_private(page, 0);
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 	/*
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@@ -149,29 +145,14 @@
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 static inline void balloon_page_insert(struct balloon_dev_info *balloon,
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 				       struct page *page)
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 {
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-	__SetPageBalloon(page);
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+	__SetPageOffline(page);
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 	list_add(&page->lru, &balloon->pages);
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 }
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 static inline void balloon_page_delete(struct page *page)
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 {
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-	__ClearPageBalloon(page);
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+	__ClearPageOffline(page);
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 	list_del(&page->lru);
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-}
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-
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-static inline bool __is_movable_balloon_page(struct page *page)
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-{
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-	return false;
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-}
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-
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-static inline bool balloon_page_movable(struct page *page)
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-{
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-	return false;
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-}
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-
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-static inline bool isolated_balloon_page(struct page *page)
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-{
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-	return false;
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 }
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 static inline bool balloon_page_isolate(struct page *page)