From: Zi Yan Subject: mm: page_isolation: enable arbitrary range page isolation. Now start_isolate_page_range() is ready to handle arbitrary range isolation, so move the alignment check/adjustment into the function body. Do the same for its counterpart undo_isolate_page_range(). alloc_contig_range(), its caller, can pass an arbitrary range instead of a MAX_ORDER_NR_PAGES aligned one. Link: https://lkml.kernel.org/r/20220425143118.2850746-5-zi.yan@sent.com Signed-off-by: Zi Yan Cc: Christophe Leroy Cc: David Hildenbrand Cc: Eric Ren Cc: kernel test robot Cc: Mel Gorman Cc: Mike Rapoport Cc: Minchan Kim Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/page_alloc.c | 16 ++-------------- mm/page_isolation.c | 33 ++++++++++++++++----------------- 2 files changed, 18 insertions(+), 31 deletions(-) --- a/mm/page_alloc.c~mm-page_isolation-enable-arbitrary-range-page-isolation +++ a/mm/page_alloc.c @@ -8924,16 +8924,6 @@ void *__init alloc_large_system_hash(con } #ifdef CONFIG_CONTIG_ALLOC -static unsigned long pfn_max_align_down(unsigned long pfn) -{ - return ALIGN_DOWN(pfn, MAX_ORDER_NR_PAGES); -} - -static unsigned long pfn_max_align_up(unsigned long pfn) -{ - return ALIGN(pfn, MAX_ORDER_NR_PAGES); -} - #if defined(CONFIG_DYNAMIC_DEBUG) || \ (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE)) /* Usage: See admin-guide/dynamic-debug-howto.rst */ @@ -9075,8 +9065,7 @@ int alloc_contig_range(unsigned long sta * put back to page allocator so that buddy can use them. */ - ret = start_isolate_page_range(pfn_max_align_down(start), - pfn_max_align_up(end), migratetype, 0, gfp_mask); + ret = start_isolate_page_range(start, end, migratetype, 0, gfp_mask); if (ret) goto done; @@ -9157,8 +9146,7 @@ int alloc_contig_range(unsigned long sta free_contig_range(end, outer_end - end); done: - undo_isolate_page_range(pfn_max_align_down(start), - pfn_max_align_up(end), migratetype); + undo_isolate_page_range(start, end, migratetype); return ret; } EXPORT_SYMBOL(alloc_contig_range); --- a/mm/page_isolation.c~mm-page_isolation-enable-arbitrary-range-page-isolation +++ a/mm/page_isolation.c @@ -435,7 +435,6 @@ failed: * be MIGRATE_ISOLATE. * @start_pfn: The lower PFN of the range to be isolated. * @end_pfn: The upper PFN of the range to be isolated. - * start_pfn/end_pfn must be aligned to pageblock_order. * @migratetype: Migrate type to set in error recovery. * @flags: The following flags are allowed (they can be combined in * a bit mask) @@ -482,33 +481,33 @@ int start_isolate_page_range(unsigned lo { unsigned long pfn; struct page *page; + /* isolation is done at page block granularity */ + unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages); + unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages); int ret; - BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages)); - BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages)); - - /* isolate [start_pfn, start_pfn + pageblock_nr_pages) pageblock */ - ret = isolate_single_pageblock(start_pfn, gfp_flags, false); + /* isolate [isolate_start, isolate_start + pageblock_nr_pages) pageblock */ + ret = isolate_single_pageblock(isolate_start, gfp_flags, false); if (ret) return ret; - /* isolate [end_pfn - pageblock_nr_pages, end_pfn) pageblock */ - ret = isolate_single_pageblock(end_pfn, gfp_flags, true); + /* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */ + ret = isolate_single_pageblock(isolate_end, gfp_flags, true); if (ret) { - unset_migratetype_isolate(pfn_to_page(start_pfn), migratetype); + unset_migratetype_isolate(pfn_to_page(isolate_start), migratetype); return ret; } /* skip isolated pageblocks at the beginning and end */ - for (pfn = start_pfn + pageblock_nr_pages; - pfn < end_pfn - pageblock_nr_pages; + for (pfn = isolate_start + pageblock_nr_pages; + pfn < isolate_end - pageblock_nr_pages; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); if (page && set_migratetype_isolate(page, migratetype, flags, start_pfn, end_pfn)) { - undo_isolate_page_range(start_pfn, pfn, migratetype); + undo_isolate_page_range(isolate_start, pfn, migratetype); unset_migratetype_isolate( - pfn_to_page(end_pfn - pageblock_nr_pages), + pfn_to_page(isolate_end - pageblock_nr_pages), migratetype); return -EBUSY; } @@ -524,12 +523,12 @@ void undo_isolate_page_range(unsigned lo { unsigned long pfn; struct page *page; + unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages); + unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages); - BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages)); - BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages)); - for (pfn = start_pfn; - pfn < end_pfn; + for (pfn = isolate_start; + pfn < isolate_end; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); if (!page || !is_migrate_isolate_page(page)) _