mm/khugepaged: continue to collapse on SCAN_PMD_NONE

SCAN_PMD_NONE means current pmd is empty, but we can still continue
collapse next pmd range.

Link: https://lkml.kernel.org/r/20251114030028.7035-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 1fc8986a28b3d132e6cd880aa575ad3fa8753b23..2ee5048b764e2c306faf90b8db7d010f5ae80413 100644 (file)
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2833,6 +2833,7 @@ handle_result:
                        goto handle_result;
                /* Whitelisted set of results where continuing OK */
                case SCAN_PMD_NULL:
+               case SCAN_PMD_NONE:
                case SCAN_PTE_NON_PRESENT:
                case SCAN_PTE_UFFD_WP:
                case SCAN_LACK_REFERENCED_PAGE: