Re: [RFC PATCH] mm: Enable khugepaged to operate on non-writable VMAs

[David Hildenbrand <david@redhat.com>]

>> @@ -676,9 +676,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
>>   			writable = true;
>>   	}
>>   
>> -	if (unlikely(!writable)) {
>> -		result = SCAN_PAGE_RO;
>> -	} else if (unlikely(cc->is_khugepaged && !referenced)) {
>> +	if (unlikely(cc->is_khugepaged && !referenced)) {
>>   		result = SCAN_LACK_REFERENCED_PAGE;
>>   	} else {
>>   		result = SCAN_SUCCEED;
>> @@ -1421,9 +1419,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
>>   		     mmu_notifier_test_young(vma->vm_mm, _address)))
>>   			referenced++;
>>   	}
>> -	if (!writable) {
>> -		result = SCAN_PAGE_RO;
>> -	} else if (cc->is_khugepaged &&
>> +	if (cc->is_khugepaged &&
> 
> The only practical use of the writable is gone. The only other usage is
> tracing which can be dropped to as it is not actionable anymore.
> 
> Could you drop writable? Maybe as a separate commit.

I think we should just do it in the same patch.

-- 
Cheers

David / dhildenb