1 // SPDX-License-Identifier: GPL-2.0
7 #include <linux/page-isolation.h>
8 #include <linux/pageblock-flags.h>
25  * check without lock_page also may miss some movable non-lru pages at
41 		  pageblock_start_pfn(end_pfn - 1));  in has_unmovable_pages()
92 			skip_pages = folio_nr_pages(folio) - folio_page_idx(folio, page);  in has_unmovable_pages()
93 			pfn += skip_pages - 1;  in has_unmovable_pages()
101 		 * because their page->_refcount is zero at all time.  in has_unmovable_pages()
105 				pfn += (1 << buddy_order(page)) - 1;  in has_unmovable_pages()
158 	spin_lock_irqsave(&zone->lock, flags);  in set_migratetype_isolate()
166 		spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
167 		return -EBUSY;  in set_migratetype_isolate()
185 			spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
186 			return -EBUSY;  in set_migratetype_isolate()
188 		zone->nr_isolate_pageblock++;  in set_migratetype_isolate()
189 		spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
193 	spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
196 		 * printk() with zone->lock held will likely trigger a  in set_migratetype_isolate()
202 	return -EBUSY;  in set_migratetype_isolate()
214 	spin_lock_irqsave(&zone->lock, flags);  in unset_migratetype_isolate()
250 	 * onlining - just onlined memory won't immediately be considered for  in unset_migratetype_isolate()
263 	zone->nr_isolate_pageblock--;  in unset_migratetype_isolate()
265 	spin_unlock_irqrestore(&zone->lock, flags);  in unset_migratetype_isolate()
285  * isolate_single_pageblock() -- tries to isolate a pageblock that might be
286  * within a free or in-use page.
287  * @boundary_pfn:		pageblock-aligned pfn that a page might cross
295  * Free and in-use pages can be as big as MAX_PAGE_ORDER and contain more than one
304  * in-use page and freed later, __free_one_page() does not split the free page
306  * the in-use page then splitting the free page.
321 		isolate_pageblock = boundary_pfn - pageblock_nr_pages;  in isolate_single_pageblock()
328 	 * free or in-use page. Also make sure all to-be-isolated pageblocks  in isolate_single_pageblock()
333 				      zone->zone_start_pfn);  in isolate_single_pageblock()
348 	 * Bail out early when the to-be-isolated pageblock does not form  in isolate_single_pageblock()
349 	 * a free or in-use page across boundary_pfn:  in isolate_single_pageblock()
363 		if (!pfn_to_online_page(boundary_pfn - 1))  in isolate_single_pageblock()
368 		struct page *page = __first_valid_page(pfn, boundary_pfn - pfn);  in isolate_single_pageblock()
394 		 * pages are freed as order-0 chunks, and LRU pages  in isolate_single_pageblock()
432 	return -EBUSY;  in isolate_single_pageblock()
436  * start_isolate_page_range() - mark page range MIGRATE_ISOLATE
442  *			MEMORY_OFFLINE - isolate to offline (!allocate) memory
445  *			REPORT_FAILURE - report details about the failure to
450  * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
453  * other than MOVABLE or CMA, this will fail with -EBUSY. For isolating all
462  * from trying to isolate overlapping ranges. If this happens, one thread
463  * will notice pageblocks in the overlapping range already set to isolate.
466  * pageblocks we may have modified and return -EBUSY to caller. This
467  * prevents two threads from simultaneously working on overlapping ranges.
478  * Return: 0 on success and -EBUSY if any part of range cannot be isolated.
497 	if (isolate_start == isolate_end - pageblock_nr_pages)  in start_isolate_page_range()
500 	/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */  in start_isolate_page_range()
510 	     pfn < isolate_end - pageblock_nr_pages;  in start_isolate_page_range()
517 				pfn_to_page(isolate_end - pageblock_nr_pages),  in start_isolate_page_range()
519 			return -EBUSY;  in start_isolate_page_range()
526  * undo_isolate_page_range - undo effects of start_isolate_page_range()
554  * zone->lock must be held before call this.
592  * test_pages_isolated - check if pageblocks in range are isolated
604  * Returns 0 if true, -EBUSY if one or more pages are in use.
624 	page = __first_valid_page(start_pfn, end_pfn - start_pfn);  in test_pages_isolated()
626 		ret = -EBUSY;  in test_pages_isolated()
632 	spin_lock_irqsave(&zone->lock, flags);  in test_pages_isolated()
634 	spin_unlock_irqrestore(&zone->lock, flags);  in test_pages_isolated()
636 	ret = pfn < end_pfn ? -EBUSY : 0;  in test_pages_isolated()