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[79.242.52.184]) by smtp.gmail.com with ESMTPSA id n1sm9827003wrc.54.2021.12.17.10.11.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 17 Dec 2021 10:11:16 -0800 (PST) Message-ID: <7f35b4a3-8a31-d74c-fcc0-ecc87071d9a5@redhat.com> Date: Fri, 17 Dec 2021 19:11:15 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v1 03/11] mm: simplify hugetlb and file-THP handling in __page_mapcount() To: Mike Kravetz , linux-kernel@vger.kernel.org Cc: Andrew Morton , Hugh Dickins , Linus Torvalds , David Rientjes , Shakeel Butt , John Hubbard , Jason Gunthorpe , Mike Rapoport , Yang Shi , "Kirill A . Shutemov" , Matthew Wilcox , Vlastimil Babka , Jann Horn , Michal Hocko , Nadav Amit , Rik van Riel , Roman Gushchin , Andrea Arcangeli , Peter Xu , Donald Dutile , Christoph Hellwig , Oleg Nesterov , Jan Kara , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org References: <20211217113049.23850-1-david@redhat.com> <20211217113049.23850-4-david@redhat.com> <0b0007b3-bf6f-ccd7-96cf-3dd861abf224@oracle.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <0b0007b3-bf6f-ccd7-96cf-3dd861abf224@oracle.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 61F9C1A0012 X-Stat-Signature: 49z94og6y615nqahenznbhscwqp6t3y1 Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=cMahuuQy; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf19.hostedemail.com: domain of david@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=david@redhat.com X-Rspamd-Server: rspam02 X-HE-Tag: 1639764680-60312 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 17.12.21 19:06, Mike Kravetz wrote: > On 12/17/21 03:30, David Hildenbrand wrote: >> Let's return early for hugetlb, which really only relies on the compound >> mapcount so far and does not support PageDoubleMap() yet. Use the chance > > It is too early to say if hugetlb double mapping will use PageDoubleMap(). > I do not think (hope) it will be necessary. So, I think you can drop mention > of it here. Desires have most certainly been expressed from a couple of parties -- to PTE map huge pages :) Hopefully we'll find a way to avoid PageDoubleMap, I agree. Dropping the comment! > >> to cleanup the file-THP case to make it easier to grasp. While at it, use >> head_compound_mapcount(). >> >> This is a preparation for further changes. >> >> Reviewed-by: Peter Xu >> Signed-off-by: David Hildenbrand > > Acked-by: Mike Kravetz > Thanks! -- Thanks, David / dhildenb