Re: [PATCH] mm/hmm: replace hmm_update with mmu_notifier_range

[Michal Hocko]

On Wed 24-07-19 17:33:05, Christoph Hellwig wrote:
> On Wed, Jul 24, 2019 at 12:28:58PM -0300, Jason Gunthorpe wrote:
> > Humm. Actually having looked this some more, I wonder if this is a
> > problem:
> 
> What a mess.
> 
> Question: do we even care for the non-blocking events?  The only place
> where mmu_notifier_invalidate_range_start_nonblock is called is the oom
> killer, which means the process is about to die and the pagetable will
> get torn down ASAP.  Should we just skip them unconditionally?

How do you tell whether they are going to block or not without trying?
-- 
Michal Hocko
SUSE Labs