Re: [PATCH] mm/mmu_notifier: Remove non_block_start/end() from notifier invocation

[Jason Gunthorpe]

On Tue, Aug 11, 2026 at 04:15:36PM +0100, David Woodhouse wrote:
> On Tue, 2026-08-11 at 11:27 -0300, Jason Gunthorpe wrote:
> > 
> > The unstated secondary purprose of the atomic context is to force the
> > driver implementors to make sane choices that don't degrade the MM
> > spectacularly.
> 
> You realise it only does this is in the OOM handler context when the
> normal death of the process takes too long, and I literally had to hack
> the kernel to even get the splat to trigger in the first place, right?
> 
> I don't think it's keeping your driver authors honest... :)

It is documented to be like this, even if it is hard to test..

Even for normal blocking notifiers you should not be using
synchronize_rcu().

Jason