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Howlett" , Miguel Ojeda , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Trevor Gross , Danilo Krummrich , Will Deacon , Mark Rutland , linux-mm@kvack.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] rust: page: add byte-wise atomic memory copy methods Message-ID: <20260213143551.GW2995752@noisy.programming.kicks-ass.net> References: <20260213-page-volatile-io-v3-1-d60487b04d40@kernel.org> <20260213112837.GT2995752@noisy.programming.kicks-ass.net> <87a4xcu80n.fsf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87a4xcu80n.fsf@kernel.org> X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: CA25C4000F X-Stat-Signature: t4occ8ei9dce5tw4guhjkda9wpbcrqe6 X-Rspam-User: X-HE-Tag: 1770993356-514970 X-HE-Meta: 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 /sFN5DPt uJHzw8nCPAhBLxqHgDxLZpQXzL+tjhyzrQE2VoTNIPMiylWbtW2gqWHUn/gvY4/Z6GSxQEfwO/1o9g/S9Z7iC7Dqf+Fg6D1/AI6aOFhRIHkoyRtKUljJ5TcDOe1Ybq2MekUh1juKRmrc2xVyAUj5NuwxAfJSb2VvqkzytOJlVv9KG+miZvxZbV+4j+X5JmPeGBQTVDPvNKtGerV2Z9q2Ug3KTqT0HFDDS2PJVqidIatmsoTXRsadaSOzo8sRtqZQ5o/S1Wnc4SazrcYEuPReNTsK1Ny1BD/rNP1q1 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: List-Subscribe: List-Unsubscribe: On Fri, Feb 13, 2026 at 01:45:28PM +0100, Andreas Hindborg wrote: > > And same comment as for v2, none of this makes sense. Byte loads are not > > magically atomic. And they don't actually fix anything. > > I am curious about on what architectures byte loads can tear? That's not the point. It's just a byte load, not an atomic byte load. Unless you're thinking of using load-exclusive or something along those lines; but that would be completely insane, nor actually solve the problem.