Re: [PATCH] tools/testing/selftests/vm/mlock2-tests: fix mlock2 false-negative errors

[Rafael Aquini]

On Thu, Mar 26, 2020 at 12:58:09PM -0700, Andrew Morton wrote:
> On Thu, 26 Mar 2020 07:49:09 +0100 Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> 
> > On Wed 25-03-20 17:49:49, Andrew Morton wrote:
> > > On Tue, 24 Mar 2020 11:49:10 -0400 Rafael Aquini <aquini@xxxxxxxxxx> wrote:
> > > 
> > > > Thanks Michal!
> > > > 
> > > >  
> > > > Acked-by: Rafael Aquini <aquini@xxxxxxxxxx>
> > > 
> > > I'll add
> > > Fixes: 9c4e6b1a7027f ("mm, mlock, vmscan: no more skipping pagevecs")
> > 
> > Wouldn't be this misleading? It would suggest that this commit is
> > somehow incorrect. I would consider b3b0d09c7a23 ("selftests: vm: add
> > tests for lock on fault") to be a better fit.
> 
> Yes, it's a bit misleading.
> 
> Or maybe not.  b3b0d09c7a23 was merged in 2015 and worked OK (afaik)
> until 9c4e6b1a7027f came along in 2020.  So arguably, 2020's
> 9c4e6b1a7027f was correct but incomplete, since it failed to repair the
> impact upon the test code.
>

That's correct, and it was my reading, as well.
 
> I don't think that kernels prior to 2020's 9c4e6b1a7027f require this
> change(?), so we only need to backport this into 5.6.x, which is what
> my proposed Fixes: and cc:stable expresses.
> 

Agreed

-- Rafael