On 15.10.25 10:27, Kevin Brodsky wrote:

powerpc decides at runtime whether the lazy MMU mode should be used.

To avoid the overhead associated with managing
task_struct::lazy_mmu_state if the mode isn't used, introduce
arch_wants_lazy_mmu_mode() and bail out of lazy_mmu_mode_* if it
returns false. Add a default definition returning true, and an
appropriate implementation for powerpc.

Signed-off-by: Kevin Brodsky <redacted>
---
This patch seemed like a good idea to start with, but now I'm not so
sure that the churn added to the generic layer is worth it.

Exactly my thoughts :)

I think we need evidence that this is really worth it for optimizing out 
basically a counter update on powerpc.

-- 
Cheers

David / dhildenb