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Date: Tue, 20 Mar 2018 10:50:09 -0700
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2] mm: Warn on lock_page() from reclaim context.
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To: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>, kirill@shutemov.name, linux-mm@kvack.org, kirill.shutemov@linux.intel.com

On Tue, 20 Mar 2018 09:44:45 +0100 Michal Hocko <mhocko@suse.com> wrote:

> > And I wonder if overloading CONFIG_PROVE_LOCKING is appropriate here. 
> > CONFIG_PROVE_LOCKING is a high-level thing under which a whole bunch of
> > different debugging options may exist.
> 
> Yes but it is meant to catch locking issues in general so I think doing
> this check under the same config makes sense.
> 
> > I guess we should add a new config item under PROVE_LOCKING,
> 
> I am not convinced a new config is really worth it. We have way too many
> already and PROVE_LOCKING sounds like a good fit to me.

I few scruffy misc sites have used PROVE_LOCKING in this fashion, but
they really shouldn't have.  It means that if anyone wants to enable,
say, "Locking API boot-time self-tests" then they must enable
PROVE_LOCKING, so they accidentally get this feature as well.