Re: [PATCH v4 09/12] powerpc/mm: replace batch->active with in_lazy_mmu_mode()

On 03/11/2025 16:05, David Hildenbrand wrote:

On 29.10.25 11:09, Kevin Brodsky wrote:

quoted

A per-CPU batch struct is activated when entering lazy MMU mode; its
lifetime is the same as the lazy MMU section (it is deactivated when
leaving the mode). Preemption is disabled in that interval to ensure
that the per-CPU reference remains valid.

The generic lazy_mmu layer now tracks whether a task is in lazy MMU
mode. We can therefore use the generic helper in_lazy_mmu_mode()
to tell whether a batch struct is active instead of tracking it
explicitly.

Signed-off-by: Kevin Brodsky <redacted>
---

I suspect you were not able to test this on real HW. Some help from
the ppc folks would be appreciated.

Indeed, it would be nice to get some testing on ppc HW that actually
uses lazy MMU (!radix_enabled()).

LGTM, but the interaction with pause/resume adds a bit of complication
on top.

Does it? This series doesn't change when arch_enter() and arch_leave()
are called, batch->active and in_lazy_mmu_mode() should coincide. 

- Kevin