Re: [PATCH V2 3/5] mm/khugepaged: change collapse_pte_mapped_thp() to return void

From: Garg, Shivank

Date: Sun Jan 18 2026 - 14:42:50 EST




On 1/16/2026 5:18 AM, David Hildenbrand (Red Hat) wrote:
> On 12/24/25 12:13, Shivank Garg wrote:
>> The only external caller of collapse_pte_mapped_thp() is uprobe, which
>> ignores the return value. Change the external API to return void to
>> simplify the interface.
>>
>> Introduce try_collapse_pte_mapped_thp() for internal use that preserves
>> the return value. This prepares for future patch that will convert
>> the return type to use enum scan_result.
>>
>> Suggested-by: David Hildenbrand (Red Hat) <david@xxxxxxxxxx>
>> Signed-off-by: Shivank Garg <shivankg@xxxxxxx>
>> ---
>>   include/linux/khugepaged.h |  9 ++++-----
>>   mm/khugepaged.c            | 40 ++++++++++++++++++++++----------------
>>   2 files changed, 27 insertions(+), 22 deletions(-)
>>
>> diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h
>> index eb1946a70cff..37b992b22bba 100644
>> --- a/include/linux/khugepaged.h
>> +++ b/include/linux/khugepaged.h
>> @@ -17,8 +17,8 @@ extern void khugepaged_enter_vma(struct vm_area_struct *vma,
>>                    vm_flags_t vm_flags);
>>   extern void khugepaged_min_free_kbytes_update(void);
>>   extern bool current_is_khugepaged(void);
>> -extern int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
>> -                   bool install_pmd);
>> +extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
>> +                    bool install_pmd);
>
>
> Sorry for late review.
>
> We remove the "extern" whenever we touch functions.
>
> Nit: two tab indent on second parameter line. Same applies for the other code you touch below (if you already adjust that line, just indent with two tabs).
>
>
> Acked-by: David Hildenbrand (Red Hat) <david@xxxxxxxxxx>
>

Thank you for the review.
I've always been unsure about when to use two-tab indent versus aligning
with the opening bracket. I'll follow the two-tab indent convention going
forward.

I have incorporated these reviews in V3 here:
https://lore.kernel.org/linux-mm/20260118192253.9263-4-shivankg@xxxxxxx

Best Regards,
Shivank