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[209.85.218.42]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-abf0c7bbfb5sm167589666b.170.2025.02.27.11.16.11 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 Feb 2025 11:16:11 -0800 (PST) Received: by mail-ej1-f42.google.com with SMTP id a640c23a62f3a-abb7520028bso170514066b.3 for ; Thu, 27 Feb 2025 11:16:11 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCUAOd9dzOlwXay5cUuz33dVqmvRj4f+lMqAA+WcbQYvVJLH36IikDXSgskU69jUSTrAF/RW3Fpe@lists.linux.dev X-Received: by 2002:a17:907:86ac:b0:ab6:df79:f577 with SMTP id a640c23a62f3a-abf25d945c1mr67115866b.9.1740683771357; Thu, 27 Feb 2025 11:16:11 -0800 (PST) Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <6pwjvkejyw2wjxobu6ffeyolkk2fppuuvyrzqpigchqzhclnhm@v5zhfpmirk2c> <5d7363b0-785c-4101-8047-27cb7afb0364@ralfj.de> <0f3bc0e8-5111-4e2f-83b5-36b3aec0cbbd@ralfj.de> In-Reply-To: <0f3bc0e8-5111-4e2f-83b5-36b3aec0cbbd@ralfj.de> From: Linus Torvalds Date: Thu, 27 Feb 2025 11:15:54 -0800 X-Gmail-Original-Message-ID: X-Gm-Features: AQ5f1Jptz1SWwyUusZnRoigWvZHElhRRDe0KZ_mwrHUSOFHPo4sqdKCJh4Qdo6A Message-ID: Subject: Re: C aggregate passing (Rust kernel policy) To: Ralf Jung Cc: Kent Overstreet , Martin Uecker , "Paul E. McKenney" , Alice Ryhl , Ventura Jack , Gary Guo , airlied@gmail.com, boqun.feng@gmail.com, david.laight.linux@gmail.com, ej@inai.de, gregkh@linuxfoundation.org, hch@infradead.org, hpa@zytor.com, ksummit@lists.linux.dev, linux-kernel@vger.kernel.org, miguel.ojeda.sandonis@gmail.com, rust-for-linux@vger.kernel.org Content-Type: text/plain; charset="UTF-8" On Thu, 27 Feb 2025 at 10:33, Ralf Jung wrote: > > The way you do global flags in Rust is like this: Note that I was really talking mainly about the unsafe cases, an din particular when interfacing with C code. Also, honestly: > FLAG.store(true, Ordering::SeqCst); // or release/acquire/relaxed I suspect in reality it would be hidden as accessor functions, or people just continue to write things in C. Yes, I know all about the C++ memory ordering. It's not only a standards mess, it's all very illegible code too. Linus