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) {
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.
Reviewed-by: Dev Jain dev.jain@arm.com
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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.
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
I hope you must have rebased since your previous patch got pulled, and the difference of time between these two events is less than 1.5 hours :)
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On Fri, Aug 22, 2025 at 01:08:57PM +0530, Dev Jain wrote:
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Now deleted.
On Fri, Aug 22, 2025 at 01:08:57PM +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
I hope you must have rebased since your previous patch got pulled, and the difference of time between these two events is less than 1.5 hours :)
Thanks
I took a look at the latest mm-new, this one applies.
On 22 Aug 2025, at 2:33, 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++;-- 2.34.1
LGTM. Reviewed-by: Zi Yan ziy@nvidia.com
-- Best Regards, Yan, Zi
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