On 2024/8/16 12:58, Andrew Morton wrote:
On Fri, 16 Aug 2024 12:06:25 +0800 Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:The gigantic page size may larger than memory block size, so memory offline always fails in this case after commit b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity"), offline_pages start_isolate_page_range start_isolate_page_range(isolate_before=true) isolate [isolate_start, isolate_start + pageblock_nr_pages) start_isolate_page_range(isolate_before=false) isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock __alloc_contig_migrate_range isolate_migratepages_range isolate_migratepages_block isolate_or_dissolve_huge_page if (hstate_is_gigantic(h)) return -ENOMEM; In fact, we don't need to migrate page in page range isolation, for memory offline path, there is do_migrate_range() to move the pages. For contig allocation, there is another __alloc_contig_migrate_range() after isolation to migrate the pages. So fix issue by skipping the __alloc_contig_migrate_range() in isolate_single_pageblock(). Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity")Should we backport this into -stable kernels?
Better to backport to stable since memory offline always fail in this case.
