Re: [RFC PATCH] mm: khugepaged: decouple SHMEM and file folios' collapse

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 2025/5/12 16:08, David Hildenbrand wrote:
>>   static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int 
>> *result,
>>                           struct collapse_control *cc)
>> @@ -2436,7 +2427,7 @@ static unsigned int 
>> khugepaged_scan_mm_slot(unsigned int pages, int *result,
>>               VM_BUG_ON(khugepaged_scan.address < hstart ||
>>                     khugepaged_scan.address + HPAGE_PMD_SIZE >
>>                     hend);
>> -            if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) {
>> +            if (!vma_is_anonymous(vma)) {
>>                   struct file *file = get_file(vma->vm_file);
>>                   pgoff_t pgoff = linear_page_index(vma,
>>                           khugepaged_scan.address);
>> @@ -2782,7 +2773,7 @@ int madvise_collapse(struct vm_area_struct *vma, 
>> struct vm_area_struct **prev,
>>           mmap_assert_locked(mm);
>>           memset(cc->node_load, 0, sizeof(cc->node_load));
>>           nodes_clear(cc->alloc_nmask);
>> -        if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) {
>> +        if (!vma_is_anonymous(vma)) {
>>               struct file *file = get_file(vma->vm_file);
>>               pgoff_t pgoff = linear_page_index(vma, addr);
> 
> Yeah, I've been complaining about these checks for too long :)

Yes, I know:)

> I assume this is fine

I tested khugepaged selftest, and no issues found.

> Acked-by: David Hildenbrand <david@redhat.com>

Thanks.