On Fri, Mar 17, 2023 at 06:50:17PM +0100, David Hildenbrand wrote: > On 17.03.23 16:35, Kirill A. Shutemov wrote: > > Normal page init path frees pages during the boot in MAX_ORDER chunks, > > but deferred page init path does it in pageblock blocks. > > > > Change deferred page init path to work in MAX_ORDER blocks. > > > > For cases when pageblock is larger than MAX_ORDER, set migrate type to > > MIGRATE_MOVABLE for all pageblocks covered by the page. > > See > > commit b3d40a2b6d10c9d0424d2b398bf962fb6adad87e > Author: David Hildenbrand <david@xxxxxxxxxx> > Date: Tue Mar 22 14:43:20 2022 -0700 > > mm: enforce pageblock_order < MAX_ORDER > Some places in the kernel don't really expect pageblock_order >= > MAX_ORDER, and it looks like this is only possible in corner cases: > 1) CONFIG_DEFERRED_STRUCT_PAGE_INIT we'll end up freeing pageblock_order > pages via __free_pages_core(), which cannot possibly work. > > ... > > How should it still happen? I got the sentence backwards. It suppose to be For cases when MAX_ORDER is larger than pageblock, set migrate type to MIGRATE_MOVABLE for all pageblocks covered by the page. -- Kiryl Shutsemau / Kirill A. Shutemov
