On Fri, Aug 22, 2025 at 01:04:51PM +0530, Dev Jain wrote:
On 22/08/25 12:03 pm, Wei Yang wrote:
Commit 8ee53820edfd ("thp: mmu_notifier_test_young") introduced mmu_notifier_test_young(), but we should pass the address need to test. In xxx_scan_pmd(), the actual iteration address is "_address" not "address". We seem to misuse the variable on the very beginning.
Change it to the right one.
Fixes: 8ee53820edfd ("thp: mmu_notifier_test_young") Signed-off-by: Wei Yang richard.weiyang@gmail.com Cc: David Hildenbrand david@redhat.com Cc: Lorenzo Stoakes lorenzo.stoakes@oracle.com Cc: Zi Yan ziy@nvidia.com Cc: Baolin Wang baolin.wang@linux.alibaba.com Cc: Liam R. Howlett Liam.Howlett@oracle.com Cc: Nico Pache npache@redhat.com Cc: Ryan Roberts ryan.roberts@arm.com Cc: Dev Jain dev.jain@arm.com Cc: Barry Song baohua@kernel.org CC: stable@vger.kernel.org
The original commit 8ee53820edfd is at 2011. Then the code is moved to khugepaged.c in commit b46e756f5e470 ("thp: extract khugepaged from mm/huge_memory.c") in 2022.
mm/khugepaged.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 24e18a7f8a93..b000942250d1 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1418,7 +1418,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, if (cc->is_khugepaged && (pte_young(pteval) || folio_test_young(folio) || folio_test_referenced(folio) || mmu_notifier_test_young(vma->vm_mm,
address)))
_address))) referenced++; } if (!writable) {Wow, I have gone through this code so many times and never noticed this.
Yeah, also I am surprised when noticing it.