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From:   Mina Almasry <almasrymina@google.com>
Date:   Wed, 10 Nov 2021 09:50:13 -0800
Message-ID: <CAHS8izP9zJYfqmDouA1otnD-CsQtWJSta0KhOQq81qLSTOHB4Q@mail.gmail.com>
Subject: Re: [PATCH v4] mm: Add PM_HUGE_THP_MAPPING to /proc/pid/pagemap
To:     Peter Xu <peterx@redhat.com>
Cc:     David Hildenbrand <david@redhat.com>,
        Matthew Wilcox <willy@infradead.org>,
        "Paul E . McKenney" <paulmckrcu@fb.com>,
        Yu Zhao <yuzhao@google.com>, Jonathan Corbet <corbet@lwn.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Ivan Teterevkov <ivan.teterevkov@nutanix.com>,
        Florian Schmidt <florian.schmidt@nutanix.com>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-mm@kvack.org
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On Tue, Nov 9, 2021 at 11:03 PM Peter Xu <peterx@redhat.com> wrote:
>
> The ending "_MAPPING" seems redundant to me, how about just call it "PM_THP" or
> "PM_HUGE" (as THP also means HUGE already)?
>

So I want to make it clear that the flag is set only when the page is
PMD mappend and is a THP (not hugetlbfs or some other PMD device
mapping). PM_THP would imply the flag is set only if the underlying
page is THP without regard to whether it's actually PMD mapped or not.