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Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20230522205744.2825689-1-dhowells@redhat.com> <3068545.1684872971@warthog.procyon.org.uk> <3215177.1684918030@warthog.procyon.org.uk> To: David Hildenbrand Cc: dhowells@redhat.com, Linus Torvalds , Christoph Hellwig , Jens Axboe , Al Viro , Matthew Wilcox , Jan Kara , Jeff Layton , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: Extending page pinning into fs/direct-io.c MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <98509.1685034442.1@warthog.procyon.org.uk> Content-Transfer-Encoding: quoted-printable Date: Thu, 25 May 2023 18:07:23 +0100 Message-ID: <98511.1685034443@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Rspamd-Queue-Id: 3733D10005B X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: 7e3o777ae486jy4u8pk8kq5k4wwkroiz X-HE-Tag: 1685034451-314102 X-HE-Meta: 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 k6eiRfig 3zT5u2Roip7i/XhJjibqOdqmBojslV6NZUJbSaQeh85OYW2H211mqI0db/8J05POmOmtBwYaGabxjl89iMau6uKJuNo0Iv12lbShzDFWnGN+oDm8Qyy2jWS2Uq29Ane0Qz2ANhJoS6LNAs9W5kn7XGsk2vWKG2CFzpIa/XEU5pVKzJc/Lsc2pSiCEuw== 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: David Hildenbrand wrote: > I think the correct way to test for a zero page is > is_zero_pfn(page_to_pfn(page). > = > Using my_zero_pfn(vmf->address) in do_anonymous_page() these can easily = end up > in any process. Should everywhere that is using ZERO_PAGE(0) actually be using my_zero_pfn= ()? ZERO_PAGE() could do with a kdoc comment saying how to use it. David