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 :) > -- > Thanks, > > David / dhildenb > > -- Sincerely yours, Mike.
