From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sphereful.davidgow.net (sphereful.davidgow.net [203.29.242.92]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 03BEE39E183; Thu, 26 Mar 2026 05:40:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.29.242.92 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774503652; cv=none; b=m6hw5+pBVYiZ/V0htOWZARXsDD1F1AQV8DQg0T3Lyha8n5OLema9EbZFGxe729eftfalpRoLTRH8izeMJtVQVKcuhQPyeCsKXJQehmdvIrWcUai4+rknACgc4fY+C6tt1iQvubeaT2vyjDGUcOcM03NyEUKQd7JH5/4FkEF9EtE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774503652; c=relaxed/simple; bh=n9xjHtpRhSH9ix3QmcQLv0kr4+Yq4N4rwcbqb/HE28g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=sPEMhpQZAsJbJ8B+6QTavi3lgxV5/iQifvv7HMgx25nNsHo9LjPIhg6GPVgDNmSFipQrAmFfz20oMiLLU9hj4wRy8LeQq4PYQ9ZTm+mW4OpMSAbpXNIEqjuOuRhrOPYIV4S6KhpBN9EezJWLt6LHPRUZlyvowh7IFe/TlTOk92A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=davidgow.net; spf=pass smtp.mailfrom=davidgow.net; dkim=pass (4096-bit key) header.d=davidgow.net header.i=@davidgow.net header.b=dLRebvcn; dkim=pass (4096-bit key) header.d=davidgow.net header.i=@davidgow.net header.b=ldcLAgFv; arc=none smtp.client-ip=203.29.242.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=davidgow.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=davidgow.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=davidgow.net header.i=@davidgow.net header.b="dLRebvcn"; dkim=pass (4096-bit key) header.d=davidgow.net header.i=@davidgow.net header.b="ldcLAgFv" DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=davidgow.net; s=201606; t=1774503291; bh=n9xjHtpRhSH9ix3QmcQLv0kr4+Yq4N4rwcbqb/HE28g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=dLRebvcntzwFpH7dQ1ezEtnqDQrnfqOEkALvx6okdHaLJcFTIf99TajN5GORbPKWZ pzWUXjjlB85klCEskTlHka1vHn7UFo+4kN8yYmLjwhKdVxjR4Tx2pGLccU7OvWX91b vsVM1JEIvYiMZ8cgOGZCAopB4/OvjyRL//b49SKEgkYEILkZFH2sp9LmdVYPOelCP2 P3Gft+GBYKZhwaVAddIXCBfwhTOlTRmoUUVsHAIOWmcBtj1QThwprO68PNS7mPnUJU dB+kjJ3+HtQy8CY4JmT7OeAfYlkpL2BlkbRK+AgDNs+oyCtz1E7ThssjRv15wNYTKc yQDTb44BrW7mfb4RDB095TPbgIv/8jYehe+/2A5zby9SFR5rpsa2HHaj4OrqVBiLI/ wACG+VnA1eEkKTXyCe0CaoqARO1hv1p00DHneWvEhK3puX587so1qBVLqmzoeWJj9K WIGHsIz/xlDwv4HGZ9ayBgbxsX7QP9cDGjA5v9KXYoh6HvtoRk9Pd1JjXD8034zc11 OwKwVmvhTy/14T0Qe/HagRLXKImMZDTaD3fA8MIOfweIIasKRlAR3+mxHTbtFzswDi +K3+ydlywGLxNurwWrMCSL+96gafwB0a6Q07wosQxDoM9zEuKQuBeIo8yRLYCDIdDx xFWMC4LRykuiwsrXV2HLMueA= Received: by sphereful.davidgow.net (Postfix, from userid 119) id 2C2471E833E; Thu, 26 Mar 2026 13:34:51 +0800 (AWST) X-Spam-Level: DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=davidgow.net; s=201606; t=1774503287; bh=n9xjHtpRhSH9ix3QmcQLv0kr4+Yq4N4rwcbqb/HE28g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ldcLAgFv276uo5NW6LPy7yICCVgujhSzmWWh6jq+0as7zdXji4UzHT6jmt4Pz/+33 S3izhb/lP9G6bwJL2/2H1qTs2LUaVuCj/ABRbszrZp4q62JjEXq55nTfRp2SvLuI9R fm906bBysocD7LOT3MwsI7/Yswz4Tiu7PEgJoKZ1suCr2uP3hzygBpq9Y/uHrCvnlV hL320KohBE1/nJw3XzMRLlA2C6A8q7IH7kiC+wl1eGgKbZUpqeffPGP1oYo0M96OJC b7+eOTWzv4JyqwtBOF8ElsXU3R7ytXb6QQaJ6JxxljEQwj2nIYkCAf94e9nYx5u4JE 4903DdFW1gSuzq8xO+jxBKsA7ZEGlu1on8XW++IES/3QjXnfMvh/tT99aAmzDk70mK Q12zsoXnahHRQZEKsNXsV7IS8i6e64DETF7+FG/6LFPOLnJzdxuyTYZMWVs6YLIIDG aFSeffc9zYPYLL5KHnYpKyLYtJTLbeBA1SbKt6JO1LkMj8NOUC7hfwUzjxN/oHDv2z 3/L5hJqEG8WzvGUCwLtLeVT2cCVUWYkRhKzxdIUzYLENGP4vUxvX5aCNKe1wTm38eG Uoepqbm42xqept2Sy0Ah2AWCkqIRpUM2alnyL+hUrW0AW3Nejd9c4XWG434jAvhFQB SI3cbpjzbw15rKzFZT3TjCdA= Received: from [IPV6:2001:8003:8824:9e00:6d16:7ef9:c827:387c] (unknown [IPv6:2001:8003:8824:9e00:6d16:7ef9:c827:387c]) by sphereful.davidgow.net (Postfix) with ESMTPSA id DC56A1E737C; Thu, 26 Mar 2026 13:34:46 +0800 (AWST) Message-ID: Date: Thu, 26 Mar 2026 13:34:42 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 0/3] Inline helpers into Rust without full LTO To: Miguel Ojeda , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Russell King , Richard Weinberger , Anton Ivanov , Johannes Berg , aliceryhl@google.com Cc: linux-um@lists.infradead.org, llvm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, a.hindborg@kernel.org, acourbot@nvidia.com, akpm@linux-foundation.org, bjorn3_gh@protonmail.com, boqun.feng@gmail.com, dakr@kernel.org, gary@garyguo.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lossin@kernel.org, mark.rutland@arm.com, mmaurer@google.com, nicolas.schier@linux.dev, peterz@infradead.org, rust-for-linux@vger.kernel.org, tmgross@umich.edu, urezki@gmail.com, will@kernel.org References: <20260203-inline-helpers-v2-0-beb8547a03c9@google.com> <20260322192159.88138-1-ojeda@kernel.org> Content-Language: fr From: David Gow In-Reply-To: <20260322192159.88138-1-ojeda@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 23/03/2026 à 3:21 AM, Miguel Ojeda a écrit : > On Tue, 03 Feb 2026 11:34:07 +0000 Alice Ryhl wrote: >> >> To get rid of these helper symbols, provide functionality to inline >> helpers into Rust using llvm-link. This option complements full LTO, by >> being much cheaper and avoiding incompatibility with BTF. > > I have been testing this. I think we can go ahead with it, with a few > notes. > > I will reply to a couple other bindings in separate emails to avoid > spamming people too much. > > - I will mark the Kconfig option as "(EXPERIMENTAL)", since that is > what the commit message says and it allows us to be a bit > conservative. > > > - Clang passes `-Werror=unused-command-line-argument`, which means > under arm (i.e. 32-bit) we get: > > clang: error: argument unused during compilation: '-U arm' [-Werror,-Wunused-command-line-argument] > > And under UML I see: > > clang: error: argument unused during compilation: '-I ./arch/um/include/shared' [-Werror,-Wunused-command-line-argument] > clang: error: argument unused during compilation: '-I ./arch/x86/um/shared' [-Werror,-Wunused-command-line-argument] > clang: error: argument unused during compilation: '-I ./arch/um/include/shared/skas' [-Werror,-Wunused-command-line-argument] > > So we would need e.g. `-Wno-unused-command-line-argument` there > close to the `-Wno-override-module` one, unless Kbuild or > ClangBuiltLinux thinks it is important to keep it for this case. > > On the other hand, regardless of whether we fix this (and another > issue in a separate email found thanks to the UML build), we could > instead add `depends on` listing explicitly the architectures where > this is going to be actually tested. That way maintainers can decide > whether they want to support it when they are ready. Thoughts? > > Cc'ing Nathan, Nicolas, Nick, Bill, Justin, David, UML, ARM. I'm quite happy personally to just have -Wno-unused-command-line-argument here, given that it otherwise is working pretty well on UML and 32-bit UML. That being said, I expect it won't get a lot of testing (regardless of architecture) while it's hidden behind CONFIG_EXPERT. Cheers, -- David