Re: [PATCH v2 1/2] mm/compaction: count pages and stop correctly during page isolation.

From: Matthew Wilcox
Date: Fri Oct 30 2020 - 14:13:04 EST


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"?