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()
155 	spin_lock_irqsave(&zone->lock, flags);  in set_migratetype_isolate()
163 		spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
164 		return -EBUSY;  in set_migratetype_isolate()
185 		zone->nr_isolate_pageblock++;  in set_migratetype_isolate()
189 		__mod_zone_freepage_state(zone, -nr_pages, mt);  in set_migratetype_isolate()
190 		spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
194 	spin_unlock_irqrestore(&zone->lock, flags);  in set_migratetype_isolate()
197 		 * printk() with zone->lock held will likely trigger a  in set_migratetype_isolate()
203 	return -EBUSY;  in set_migratetype_isolate()
215 	spin_lock_irqsave(&zone->lock, flags);  in unset_migratetype_isolate()
251 	 * onlining - just onlined memory won't immediately be considered for  in unset_migratetype_isolate()
261 	zone->nr_isolate_pageblock--;  in unset_migratetype_isolate()
263 	spin_unlock_irqrestore(&zone->lock, flags);  in unset_migratetype_isolate()
283  * isolate_single_pageblock() -- tries to isolate a pageblock that might be
284  * within a free or in-use page.
285  * @boundary_pfn:		pageblock-aligned pfn that a page might cross
293  * Free and in-use pages can be as big as MAX_PAGE_ORDER and contain more than one
302  * in-use page and freed later, __free_one_page() does not split the free page
304  * the in-use page then splitting the free page.
319 		isolate_pageblock = boundary_pfn - pageblock_nr_pages;  in isolate_single_pageblock()
326 	 * free or in-use page. Also make sure all to-be-isolated pageblocks  in isolate_single_pageblock()
331 				      zone->zone_start_pfn);  in isolate_single_pageblock()
346 	 * Bail out early when the to-be-isolated pageblock does not form  in isolate_single_pageblock()
347 	 * a free or in-use page across boundary_pfn:  in isolate_single_pageblock()
361 		if (!pfn_to_online_page(boundary_pfn - 1))  in isolate_single_pageblock()
366 		struct page *page = __first_valid_page(pfn, boundary_pfn - pfn);  in isolate_single_pageblock()
380 				if (split_free_page(page, order, boundary_pfn - pfn))  in isolate_single_pageblock()
412 					.order = -1,  in isolate_single_pageblock()
481 	return -EBUSY;  in isolate_single_pageblock()
485  * start_isolate_page_range() - mark page range MIGRATE_ISOLATE
491  *			MEMORY_OFFLINE - isolate to offline (!allocate) memory
494  *			REPORT_FAILURE - report details about the failure to
499  * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
502  * other than MOVABLE or CMA, this will fail with -EBUSY. For isolating all
511  * from trying to isolate overlapping ranges. If this happens, one thread
512  * will notice pageblocks in the overlapping range already set to isolate.
515  * pageblocks we may have modified and return -EBUSY to caller. This
516  * prevents two threads from simultaneously working on overlapping ranges.
527  * Return: 0 on success and -EBUSY if any part of range cannot be isolated.
546 	if (isolate_start == isolate_end - pageblock_nr_pages)  in start_isolate_page_range()
549 	/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */  in start_isolate_page_range()
559 	     pfn < isolate_end - pageblock_nr_pages;  in start_isolate_page_range()
566 				pfn_to_page(isolate_end - pageblock_nr_pages),  in start_isolate_page_range()
568 			return -EBUSY;  in start_isolate_page_range()
575  * undo_isolate_page_range - undo effects of start_isolate_page_range()
603  * zone->lock must be held before call this.
641  * test_pages_isolated - check if pageblocks in range are isolated
653  * Returns 0 if true, -EBUSY if one or more pages are in use.
673 	page = __first_valid_page(start_pfn, end_pfn - start_pfn);  in test_pages_isolated()
675 		ret = -EBUSY;  in test_pages_isolated()
681 	spin_lock_irqsave(&zone->lock, flags);  in test_pages_isolated()
683 	spin_unlock_irqrestore(&zone->lock, flags);  in test_pages_isolated()
685 	ret = pfn < end_pfn ? -EBUSY : 0;  in test_pages_isolated()