Re: [PATCH] mm: don't ioremap COWed anon pages in generic_access_phys()

From: David Hildenbrand (Arm)

Date: Fri Oct 02 2026 - 06:10:59 EST


On 10/2/26 12:02, David Hildenbrand (Arm) wrote:
> On 10/2/26 10:38, Lorenzo Stoakes (ARM) wrote:
>> On Thu, Oct 01, 2026 at 10:22:29PM +0200, David Hildenbrand (Arm) wrote:
>>>
>>
>> Sorry to say this looks schlopped.
>>
>> This guy has sent 10 series across 6 subsystems over ~21 hrs:
>>
>> https://lore.kernel.org/all/?q=f%3Angocthang2710.1999%40gmail.com
>>
>> Nguyen - please do not flood the kernel with patches, and please use the
>> Assisted-by tag for generated content.
>>
>> The original code you submitted is really not great even if the issue may
>> be valid.
>>
>> So I'd say somebody from the core team should take over this if we want to
>> come up with a patch.
>
> Yes, I'll take care of it.
>
> [...]
>>>
>>> Signed-off-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
>>
>> This looks reasonable but I hate that we have 'special' CoW overrides like
>> this :)
>
> After sending this yesterday, I concluded that we can do this cleaner: just have
>
> bool normal_page;
>
> (naming suggestions?)
>
> that express that this is something refcounted with a struct page, like
> documented for vm_normal_page().

Hmm, have to think about that once more, regarding VM_IO and if there are some
cases that would actually have to work in generic_access_phys().

--
Cheers,

David