On 13.01.22 12:36, Mike Rapoport wrote: > On Wed, Jan 12, 2022 at 11:54:49AM +0100, David Hildenbrand wrote: >> On 05.01.22 22:47, Zi Yan wrote: >>> From: Zi Yan <ziy@xxxxxxxxxx> >>> >>> This is done in addition to MIGRATE_ISOLATE pageblock merge avoidance. >>> It prepares for the upcoming removal of the MAX_ORDER-1 alignment >>> requirement for CMA and alloc_contig_range(). >>> >>> MIGRARTE_HIGHATOMIC should not merge with other migratetypes like >>> MIGRATE_ISOLATE and MIGRARTE_CMA[1], so this commit prevents that too. >>> Also add MIGRARTE_HIGHATOMIC to fallbacks array for completeness. >>> >>> [1] https://lore.kernel.org/linux-mm/20211130100853.GP3366@xxxxxxxxxxxxxxxxxxx/ >>> >>> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> >>> --- >>> include/linux/mmzone.h | 6 ++++++ >>> mm/page_alloc.c | 28 ++++++++++++++++++---------- >>> 2 files changed, 24 insertions(+), 10 deletions(-) >>> > > ... > >>> @@ -3545,8 +3553,8 @@ int __isolate_free_page(struct page *page, unsigned int order) >>> struct page *endpage = page + (1 << order) - 1; >>> for (; page < endpage; page += pageblock_nr_pages) { >>> int mt = get_pageblock_migratetype(page); >>> - if (!is_migrate_isolate(mt) && !is_migrate_cma(mt) >>> - && !is_migrate_highatomic(mt)) >>> + /* Only change normal pageblock */ >>> + if (migratetype_has_fallback(mt)) >>> set_pageblock_migratetype(page, >>> MIGRATE_MOVABLE); >>> } >> >> That part is a nice cleanup IMHO. Although the "has fallback" part is a >> bit imprecise. "migratetype_is_mergable()" might be a bit clearer. >> ideally "migratetype_is_mergable_with_other_types()". Can we come up >> with a nice name for that? > > migratetype_is_mergable() kinda implies "_with_other_types", no? > > I like migratetype_is_mergable() more than _has_fallback(). > > My $0.02 to bikeshedding :) :) Yeah, for me migratetype_is_mergable() would also be good enough. I think I was at first thinking one could mistake it with a dedicated migratetype. But such functions are historically called is_migrate_cma/is_migrate_cma/.... -- Thanks, David / dhildenb
