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Date:   Wed, 7 Oct 2020 10:48:35 -0400
From:   Jerome Glisse <jglisse@redhat.com>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Tejun Heo <tj@kernel.org>, Jan Kara <jack@suse.cz>,
        Josef Bacik <jbacik@fb.com>
Subject: Re: [PATCH 00/14] Small step toward KSM for file back page.
Message-ID: <20201007144835.GA3471400@redhat.com>
References: <20201007010603.3452458-1-jglisse@redhat.com>
 <20201007032013.GS20115@casper.infradead.org>
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On Wed, Oct 07, 2020 at 04:20:13AM +0100, Matthew Wilcox wrote:
> On Tue, Oct 06, 2020 at 09:05:49PM -0400, jglisse@redhat.com wrote:
> > The present patchset just add mapping argument to the various vfs call-
> > backs. It does not make use of that new parameter to avoid regression.
> > I am posting this whole things as small contain patchset as it is rather
> > big and i would like to make progress step by step.
> 
> Well, that's the problem.  This patch set is gigantic and unreviewable.
> And it has no benefits.  The idea you present here was discussed at
> LSFMM in Utah and I recall absolutely nobody being in favour of it.
> You claim many wonderful features will be unlocked by this, but I think
> they can all be achieved without doing any of this very disruptive work.

You have any ideas on how to achieve them without such change ? I will
be more than happy for a simpler solution but i fail to see how you can
work around the need for a pointer inside struct page. Given struct
page can not grow it means you need to be able to overload one of the
existing field, at least i do not see any otherway.

Cheers,
J?r?me