bLzkoOZm0PXxE9qwtF4gKR=cpRXrSrJ9V9Pm2DJexs985q4g@mail.gmail.com/ [1] Link: https://lkml.kernel.org/r/20251023030521.473097-1-ziy@nvidia.com Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages") Signed-off-by: Zi Yan Acked-by: David Hildenbrand Cc: Pankaj Raghav Reviewed-by: Yang Shi Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Jane Chu Cc: Lance Yang Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Luis Chamberalin Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Naoya Horiguchi Cc: Nico Pache Cc: Ryan Roberts Cc: Wei Yang Cc: Signed-off-by: Andrew Morton --- mm/huge_memory.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-preserve-pg_has_hwpoisoned-if-a-folio-is-split-to-0-order +++ a/mm/huge_memory.c @@ -3263,6 +3263,14 @@ bool can_split_folio(struct folio *folio caller_pins; } +static bool page_range_has_hwpoisoned(struct page *page, long nr_pages) +{ + for (; nr_pages; page++, nr_pages--) + if (PageHWPoison(page)) + return true; + return false; +} + /* * It splits @folio into @new_order folios and copies the @folio metadata to * all the resulting folios. @@ -3270,17 +3278,24 @@ bool can_split_folio(struct folio *folio static void __split_folio_to_order(struct folio *folio, int old_order, int new_order) { + /* Scan poisoned pages when split a poisoned folio to large folios */ + const bool handle_hwpoison = folio_test_has_hwpoisoned(folio) && new_order; long new_nr_pages = 1 << new_order; long nr_pages = 1 << old_order; long i; + folio_clear_has_hwpoisoned(folio); + + /* Check first new_nr_pages since the loop below skips them */ + if (handle_hwpoison && + page_range_has_hwpoisoned(folio_page(folio, 0), new_nr_pages)) + folio_set_has_hwpoisoned(folio); /* * Skip the first new_nr_pages, since the new folio from them have all * the flags from the original folio. */ for (i = new_nr_pages; i < nr_pages; i += new_nr_pages) { struct page *new_head = &folio->page + i; - /* * Careful: new_folio is not a "real" folio before we cleared PageTail. * Don't pass it around before clear_compound_head(). @@ -3322,6 +3337,10 @@ static void __split_folio_to_order(struc (1L << PG_dirty) | LRU_GEN_MASK | LRU_REFS_MASK)); + if (handle_hwpoison && + page_range_has_hwpoisoned(new_head, new_nr_pages)) + folio_set_has_hwpoisoned(new_folio); + new_folio->mapping = folio->mapping; new_folio->index = folio->index + i; @@ -3422,8 +3441,6 @@ static int __split_unmapped_folio(struct if (folio_test_anon(folio)) mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1); - folio_clear_has_hwpoisoned(folio); - /* * split to new_order one order at a time. For uniform split, * folio is split to new_order directly. _ Patches currently in -mm which might be from ziy@nvidia.com are mm-huge_memory-do-not-change-split_huge_page-target-order-silently.patch mm-huge_memory-preserve-pg_has_hwpoisoned-if-a-folio-is-split-to-0-order.patch+ mm-huge_memory-preserve-pg_has_hwpoisoned-if-a-folio-is-split-to-0-order.patch added to mm-hotfixes-unstable branchAndrew Morton undefinedmm-commits@vger.kernel.org,yang@os.amperecomputing.com,willy@infradead.org,stable@vger.kernel.org,ryan.roberts@arm.com,richard.weiyang@gmail.com,npache@redhat.com,nao.horiguchi@gmail.com,mcgrof@kernel.org,lorenzo.stoakes@oracle.com,linmiaohe@huawei.com,liam.howlett@oracle.com,lance.yang@linux.dev,kernel@pankajraghav.com,jane.chu@oracle.com,dev.jain@arm.com,david@redhat.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,ziy@nvidia.com,akpm@linux-foundation.org undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined×