Re: [PATCH v3 1/9] mm: fix eager write-bit restore for write-notified shared mappings

["Carlos López" <clopez@suse.de>]

On 11/13/26 9:47 PM, Lorenzo Stoakes (ARM) wrote:
>>  static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma)
>>  {
>>  	/*
>> @@ -596,19 +604,16 @@ static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma
>>  	 * if we can't do that automatically for all PTEs in a mapping. For
>>  	 * private mappings, that's always the case when we have write
>>  	 * permissions as we properly have to handle COW.
>> +	 *
>> +	 * vma->vm_page_prot lacks the write bit if writenotify is already
>> +	 * enabled, so pass it with the bits restored, as vma_set_page_prot()
>> +	 * does.
> 
> We don't write code in comments.

I'll drop it.

>>  	 */
>>  	if (vma->vm_flags & VM_SHARED)
>> -		return vma_wants_writenotify(vma, vma->vm_page_prot);
>> +		return vma_wants_writenotify(vma,
>> +		       vma_pgprot_modify(vma->vm_page_prot, vma->flags));
> 
> You mention vma_set_page_prot() but then implement it differently from there and
> make no effort to abstract it?
> 
> And so both callers now do the same thing, and both open code it... you should
> abstract that.

Okay, I'll add a helper for both.