Re: [PATCH 4/4] mm: migrate_device: use walk_page_range_vma() in migrate_vma_collect()

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 6/17/2026 9:30 PM, David Hildenbrand (Arm) wrote:
> On 6/17/26 10:26, Kefeng Wang wrote:
>> The migrate_vma_collect() uses walk_page_range() to walk the page
>> table. Fortunately, migrate_vma_setup() already validates that the
>> entire range falls within a single VMA.
>>
>> Since there is no .test_walk in migrate_vma_walk_ops and VM_PFNMAP
>> VM_PFNMAP
> 
> You mention VM_PFNMAP twice.
> 
>> has filtered by  migrate_vma_setup(), it's safetly replace
> 
> s/has/was/
> 
> s/  / /
> 
> s/safetly/safe to/
> 
>> walk_page_range() with walk_page_range_vma() to eliminates an
> 
> s/eliminates/eliminate/

Forgive my poor English, will fix them.

> 
>> unnecessary find_vma() lookup.
>>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>>   mm/migrate_device.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
>> index 554754eb26ff..ae39173d6a0e 100644
>> --- a/mm/migrate_device.c
>> +++ b/mm/migrate_device.c
>> @@ -513,7 +513,7 @@ static void migrate_vma_collect(struct migrate_vma *migrate)
>>   		migrate->pgmap_owner);
>>   	mmu_notifier_invalidate_range_start(&range);
>>   
>> -	walk_page_range(migrate->vma->vm_mm, migrate->start, migrate->end,
>> +	walk_page_range_vma(migrate->vma, migrate->start, migrate->end,
>>   			&migrate_vma_walk_ops, migrate);
>>   
>>   	mmu_notifier_invalidate_range_end(&range);
> 
> LGTM
> 
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> 

Thanks.