Re: [PATCH v1 4/7] arm64/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE

[David Hildenbrand]

On 21.03.22 19:27, Catalin Marinas wrote:
> On Mon, Mar 21, 2022 at 05:44:05PM +0000, Will Deacon wrote:
>> On Mon, Mar 21, 2022 at 04:07:48PM +0100, David Hildenbrand wrote:
>>> So the example you gave cannot possibly have that bit set. From what I
>>> understand, it should be fine. But I have no real preference: I can also
>>> just stick to the original patch, whatever you prefer.
>>
>> I think I'd prefer to stay on the safe side and stick with bit 2 as you
>> originally proposed. If we need to support crazy numbers of swapfiles
>> in future then we can revisit the idea of allocating bit 1.
> 
> Sounds fine to me. David, feel free to keep my reviewed-by on the
> original patch.
> 

Thanks both, I'll add the following comment to the patch:

"Note that we might be able to reuse bit 1, but reusing bit 1 turned out
 problematic in the past for PROT_NONE handling; so let's play safe and
 use another bit."


-- 
Thanks,

David / dhildenb