On Fri, Oct 30, 2020 at 11:57:15AM -0400, Zi Yan wrote: > In isolate_migratepages_block, when cc->alloc_contig is true, we are > able to isolate compound pages, nr_migratepages and nr_isolated did not > count compound pages correctly, causing us to isolate more pages than we > thought. Use thp_nr_pages to count pages. Otherwise, we might be trapped ^^^^^^^^^^^^ Maybe replace that sentence with "Count compound pages as the number of base pages they contain"?