On 04.12.20 17:12, Muchun Song wrote: > On Fri, Dec 4, 2020 at 12:28 AM David Hildenbrand <[email protected]> wrote: >> >> On 03.12.20 17:22, Muchun Song wrote: >>> The max order page has no buddy page and never merge to other order. >>> So isolating and then freeing it is pointless. And if order == MAX_ORDER >>> - 1, then the buddy can actually be a !pfn_valid() in some corner case? >>> pfn_valid_within(buddy_pfn) that follows would only catch it on archs >>> with holes in zone. Then is_migrate_isolate_page(buddy) might access an >>> invalid buddy. So this is also a bug fix. >>> >>> Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on >>> isolated pageblock") >> >> As just replied to v1, I don't think this is required and the patch > > You mean we should remove the Fixes tag? Thanks.
As discussed in v1, I don't think we really have systems where this applies, but could be in corner cases on MIPS or with FLATMEM. Let's just leave it like that. :) Reviewed-by: David Hildenbrand <[email protected]> -- Thanks, David / dhildenb
