Re: [PATCH v2 2/7] mm: introduce local state for lazy_mmu sections

David Hildenbrand
2025-09-12T12:41:07Z

On 12.09.25 14:37, Alexander Gordeev wrote:
> On Fri, Sep 12, 2025 at 10:55:50AM +0200, David Hildenbrand wrote:
>
> Hi David, Kevin,
>
>> Great, looking forward to seeing this all getting cleaned up and done
>> properly for good.
>
> I am currently working on lazy mmu for s390 and this nesting
> initiative kind of interferres. Well, in fact it looks like
> it does not, but I am bit lost in last couple of iterations ;)
>
> The prerequisite for s390 would be something like the change
> below. With that change I can store the context in a per-cpu
> structure and use it later in arch-specific ptep_* primitives.
>
> Moreover, with a further (experimental) rework we could use
> a custom kasan sanitizer to spot false directly compiled
> PTE accesses, as opposed to set_pte()/ptep_get() accessors.
>
> I am not quite sure see whether this could be derailed by
> the new lazy mmu API. At least I do not immediately see any
> obvious problem. But may be you do?

It would just be passing more context down to the architecture, right?

--
Cheers

David / dhildenb