Re: [PATCH v2 0/7] Nesting support for lazy MMU mode

Kevin Brodsky
2025-09-09T13:59:52Z

On 09/09/2025 11:21, David Hildenbrand wrote:
> On 09.09.25 04:16, Andrew Morton wrote:
>> On Mon,  8 Sep 2025 08:39:24 +0100 Kevin Brodsky
>> <kevin.brodsky@arm.com> wrote:
>>
>>> The main change enabling nesting is patch 2, following the approach
>>> suggested by Catalin Marinas [4]: have enter() return some state and
>>> the matching leave() take that state.
>>
>> This is so totally the correct way.  Thanks.
>
> Staring at this, I wonder if we could alternatively handle it like
> pagefault_disable()/pagefault_enable(), having something like
> current->lazy_mmu_enabled.
>
> We wouldn't have to worry about preemption in that case I guess
> (unless the arch has special requirements).
>
> Not sure if that was already discussed, just a thought.

That's an interesting point, I think I've addressed it in reply to patch
2 [1].

- Kevin

[1]