From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f46.google.com (mail-ed1-f46.google.com [209.85.208.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C41E26A1A4 for ; Thu, 27 Feb 2025 20:28:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740688114; cv=none; b=eGrWQzWy4TFHqS77h0ROQRgfLpHp/Ygchwn7IAINh7MKu1e+d+G9ThkUXpFYuGtuSCb8Wt8BbiDLYBqn1s3tmABh1QF6eCxYY7aFdEqhorfhUoBtk1VtcEP6BllVQI1aXZGKue1ZQRZb/M181SC8qWVuyWX7coILefiHw5GZzbs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740688114; c=relaxed/simple; bh=H3HVkz+A6rXVuiDniuy3LDGPxjutY3NbEPqK++G8ir8=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=ASpjCA6lJKwwn3vAjKVcj8+gXVpGIrAZVfWOh3WR8fhyA/YEZXzGMuolzV7Oj0FGz1btuwtpIaboCj6jayxES2IectzNukVRgLQf9z5/FNCPw1snmE7Ky5d6bIMsdnQZT6SiM1uP1NqwDtvrZCMYNyrlPwHB9aPocqWStKMdnJ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org; spf=pass smtp.mailfrom=linuxfoundation.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=T3ZKr7KI; arc=none smtp.client-ip=209.85.208.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linuxfoundation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="T3ZKr7KI" Received: by mail-ed1-f46.google.com with SMTP id 4fb4d7f45d1cf-5ded69e6134so2262329a12.0 for ; Thu, 27 Feb 2025 12:28:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; t=1740688110; x=1741292910; darn=lists.linux.dev; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=3iaC90NRH1e1Syvsd/il6x0lQMXHnv8BIHQEgKW5Yhc=; b=T3ZKr7KIa5Lwf7GQeed1HPlzHYkAUKCo8xdTKem2x6wZvIFBEpOrAdVyDu/eRavFOb Eti1a6AYk2rZmrJ75f10IH4wopVgn4mL/D6ZJ0nyv560qkQzGsNNY+BEpBLvMfdcxENC VjfGEQnKh///s6S36An5lpe5G5cDOlzZV6JJY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1740688110; x=1741292910; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=3iaC90NRH1e1Syvsd/il6x0lQMXHnv8BIHQEgKW5Yhc=; b=w4qxLoaqBnlnFXjoDUsXzfrMeMLbPKanRVcukYbMSWpqVP4vS+v9YR5HUO73b2zG2E 4HICkJO20/xAaTTmrQsRZNM1SOagaK1NJWKrm3QI+JFSpKDYCy/qn3AXLhZDxPLjNws3 kK+OzWLJe9dQPhbFdYLNoDtGyCQ9h+8z+cqe0Q6zguxUIyrt9989dsEkvavg9JTzZcx9 slDhl1UBzBOyuWV1H4+K0/M3jvFzQfl29r3RcLPAexF0m852nediwibgW+HflFH99r0k XPGBQ6HpyUD/HMkg9NxtGfnUXUGUVG8QqrxFYGmNxazF25oSf+MOtt8AZInj7hD8+Iz6 /37w== X-Forwarded-Encrypted: i=1; AJvYcCWhxjOOjL6a7okN5EKGkWcfx440Gj+kLp0GDzv4k80WX1y7gp+7js/0qOjZCXBFiy7OSDveM1uA@lists.linux.dev X-Gm-Message-State: AOJu0YxfrwSiQa7CBPyF1b+0Z9XdbPVOrBpoUFnqqOb6KhsX7BVLnInK zCa7LGXGX4NhoGEHpjOp9+7l3RYP6tou0wpBaKidugE3v/LFLY+XCHVfdDNqncvkHnG4JKqka80 FY5wg+Q== X-Gm-Gg: ASbGncsinPjCQOW4c1PUVjSYRiyLaO1v2Iql8/J0dp4noyrAztMjjhJc59/oYSug1Bp k6pJRoQq9EC2ACShE1eWABum6dNseDhUwMD7m71wcfr3Wviq2X8tw6UCTYbPlptoZsJb/33Cr1h j2zxJ1FlPHZI4wHW9rtn1xWwsFkPtORFpXYCI4U+Rquk0D900lVHMxjR9pncQ7puLK/lqZG7kgu o+MJxUZa2vXjcZbfqGdN8dO5lTYmAKyWdII0PWHgWQBQZ/LiUuII+1FMGN2NdIdgVKzRjN094bq bT9Mm+lvwNn2uSCNsgISfC8KKwz96w6pEFMhKqytQw9jjRVuRHOe/na7dbhi6TZJVByTmxuGhZ1 p X-Google-Smtp-Source: AGHT+IFBOmu4bmBfHFfNQ0r6lNL5oM3aZLz4a7FovxyuOJKfARDzVGNWz/GtYAQVqouGksracz4bxA== X-Received: by 2002:a17:907:7f86:b0:abe:e2ac:62db with SMTP id a640c23a62f3a-abf25d90142mr103750366b.7.1740688110100; Thu, 27 Feb 2025 12:28:30 -0800 (PST) Received: from mail-ed1-f43.google.com (mail-ed1-f43.google.com. [209.85.208.43]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-abf0c7bc008sm172628966b.166.2025.02.27.12.28.29 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 27 Feb 2025 12:28:29 -0800 (PST) Received: by mail-ed1-f43.google.com with SMTP id 4fb4d7f45d1cf-5e0b70fb1daso2178232a12.1 for ; Thu, 27 Feb 2025 12:28:29 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCUS/AKVQXORO94zgwCJ6JDGDfFCYXjtaALwEN6n3Xj65tr27y9hcyvAKhUTV/bwlJ0q9TlqL52Q@lists.linux.dev X-Received: by 2002:a17:907:c50a:b0:abe:ea93:2ca3 with SMTP id a640c23a62f3a-abf261d3cd5mr91983066b.29.1740688108692; Thu, 27 Feb 2025 12:28:28 -0800 (PST) Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <5d7363b0-785c-4101-8047-27cb7afb0364@ralfj.de> <0f3bc0e8-5111-4e2f-83b5-36b3aec0cbbd@ralfj.de> In-Reply-To: From: Linus Torvalds Date: Thu, 27 Feb 2025 12:28:12 -0800 X-Gmail-Original-Message-ID: X-Gm-Features: AQ5f1Jr2HELUmBJIPyKcHVA4YKc0nNSI_EcgaYvP2EtpcHUej5s4s67UyCptmgE Message-ID: Subject: Re: C aggregate passing (Rust kernel policy) To: Kent Overstreet Cc: Ralf Jung , 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 11:55, Kent Overstreet wrote: > > It's more explicit, and that's probably not a bad thing - compare it to > our smp_mb__after_atomic(), it's not uncommon to find code where the > barriers are missing because the person who wrote the code was assuming > x86. Sadly, judging by the memory ordering discussions I saw, I will almost guarantee you that the compiler support for memory ordering will be buggy. When we miss details in our wrappers or our users, we can fix them. And when the compilers mess up, we'll use the wrappers anyway. Linus