Re: [RFC v9 PATCH 2/4] mm: mmap: zap pages with read mmap_sem in munmap

[Yang Shi]

On 9/12/18 2:11 AM, Michal Hocko wrote:
> On Tue 11-09-18 19:29:21, Matthew Wilcox wrote:
> > On Tue, Sep 11, 2018 at 04:35:03PM -0700, Yang Shi wrote:
> [...]
>
> I didn't get to read the patch yet.

If you guys think this is the better way I could convert my patches to 
go this way. It is simple to do the conversion.

Thanks,
Yang

> > > And, Michal prefers have VM_HUGETLB and VM_PFNMAP handled separately for
> > > safe and bisectable sake, which needs call the regular do_munmap().
> > That can be introduced and then taken out ... indeed, you can split this into
> > many patches, starting with this:
> >
> > +		if (tmp->vm_file)
> > +			downgrade = false;
> >
> > to only allow this optimisation for anonymous mappings at first.
> or add a helper function to check for special cases and make the
> downgrade behavior conditional on it.