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Thu, 7 Mar 2024 12:10:57 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id 4C4FE644CE85; Thu, 7 Mar 2024 12:10:57 +0100 (CET) Date: Thu, 7 Mar 2024 12:10:57 +0100 (CET) From: Richard Weinberger To: David Hildenbrand Cc: linux-mm , linux-fsdevel , linux-kernel , Linux Doc Mailing List , upstream+pagemap@sigma-star.at, adobriyan@gmail.com, wangkefeng wang , ryan roberts , hughd@google.com, peterx@redhat.com, avagin@google.com, lstoakes@gmail.com, vbabka , Andrew Morton , usama anjum , Jonathan Corbet Message-ID: <861682210.23281.1709809857201.JavaMail.zimbra@nod.at> In-Reply-To: References: <20240306232339.29659-1-richard@nod.at> <20240306232339.29659-2-richard@nod.at> Subject: Re: [PATCH 2/2] [RFC] pagemap.rst: Document write bit MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF97 (Linux)/8.8.12_GA_3809) Thread-Topic: pagemap.rst: Document write bit Thread-Index: m4Aa6cZ4OAmz6WBRgPq7/2CUVSqXkA== X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: B9AF640019 X-Stat-Signature: a7pfuppy47yubzby97iey8bqojj5rgnf X-Rspam-User: X-HE-Tag: 1709809859-159943 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.003602, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: ----- Urspr=C3=BCngliche Mail ----- > Von: "David Hildenbrand" > An: "richard" , "linux-mm" >> + Bit 58 is useful to detect CoW mappings; however, it does not indica= te >> + whether the page mapping is writable or not. If an anonymous mapping= is >> + writable but the write bit is not set, it means that the next write = access >> + will cause a page fault, and copy-on-write will happen. >=20 > That is not true. Can you please help me correct my obvious misunderstanding?