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Date:   Mon, 25 Sep 2023 23:38:17 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Hugh Dickins <hughd@google.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Andi Kleen <ak@linux.intel.com>,
        Christoph Lameter <cl@linux.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        David Hildenbrand <david@redhat.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Yang Shi <shy828301@gmail.com>,
        Sidhartha Kumar <sidhartha.kumar@oracle.com>,
        Vishal Moola <vishal.moola@gmail.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Tejun Heo <tj@kernel.org>,
        Mel Gorman <mgorman@techsingularity.net>,
        Michal Hocko <mhocko@suse.com>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCH 06/12] mempolicy trivia: use pgoff_t in shared mempolicy
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On Mon, Sep 25, 2023 at 11:31:40PM +0100, Matthew Wilcox wrote:
> On Mon, Sep 25, 2023 at 01:28:14AM -0700, Hugh Dickins wrote:
> > Prefer the more explicit "pgoff_t" to "unsigned long" when dealing with
> > a shared mempolicy tree.  Delete confusing comment about pseudo mm vmas.
> 
> Yes, with three quibbles

Actually, a fourth has occurred to me

> >  struct sp_node {
> >  	struct rb_node nd;
> > -	unsigned long start, end;
> > +	pgoff_t start, end;
> >  	struct mempolicy *policy;
> >  };

This data structure is unused outside mempolicy.c today, and you don't
add any.  Perhaps we could move it from mempolicy.h to mempolicy.c?