From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3BCEE2AF00 for ; Fri, 14 Mar 2025 10:17:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741947469; cv=none; b=sCeuwcSvOKeKFBnoKdNgrV9q3u7+0IFGnT/pBE/KnaAeIhR0o9EMZU7CoX4GaZ3960cEGKXh9nuQ3lQvOewXiVzgHtpGcom2KZHkh1YYWYMBsHBaMp7Ip7WVILIFppIeF93KeJUgi21FML9m++7LuMtKFry6gq6O885YJoA1huM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741947469; c=relaxed/simple; bh=S6m75BNvABFyEwi0kFUZfGuKF5ZMAhOPmfUqAvqwFE8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RriihPyW3AswUFaLsJ5ThH3zQ1iEMwbB5fdf2Jl1I+eWLzddT5BUYsnCWLb2BVINKYLWwIC4++XLP7d+VcDu/fTnNvIG1L2mz1I4LyWNh4IL4XjMokHBGz76CIvXSNwYsD6yliPrSTfUP2nkawOtlMGr/Ig90rJ4Ec9EbAHCzW0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VdHEEF93; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VdHEEF93" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 229D0C4CEE3; Fri, 14 Mar 2025 10:17:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741947468; bh=S6m75BNvABFyEwi0kFUZfGuKF5ZMAhOPmfUqAvqwFE8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VdHEEF93t7r//l6heP3qlapvbf/rB8kInzDyu1/8ijyXfmbEZqo2Jn0IyezaOWaoY NNH63xbBpnEHKYDEZfQWET7LKcbWYb8LVF7Z3DnqQlzMkj9pS80hESWh5crWUhxLF2 Rbo8UfxX/ZGQ60uzCEJ8l/1COYWTCSezaB2bix2jkiJKXp2/MBLkjaMoY25MlZd988 fS2WMWTKvTeF+kvHD3rbbDlWgz5M3Nr+jP05PihHfSelkLVXSppsaVraixhJW8/PhA Aq7moZTFH8c/T0ENIwsiXlgU1aCRzNJppa86P54UG6KtU94n7Qn4L4RMVjReRr9+Kw kfIXmXtFQKxAg== Date: Fri, 14 Mar 2025 11:17:43 +0100 From: Ingo Molnar To: Borislav Petkov Cc: Uros Bizjak , x86@kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Dave Hansen , "H. Peter Anvin" , Linus Torvalds , Peter Zijlstra , Josh Poimboeuf Subject: Re: [PATCH] x86/asm: Use asm_inline() instead of asm() in amd_clear_divider() Message-ID: References: <20250313191828.83855-1-ubizjak@gmail.com> <96E2026E-CEF1-4A4C-B107-7FCE2CD9121F@alien8.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: * Ingo Molnar wrote: > > * Borislav Petkov wrote: > > > Sorry but this doesn't justify this churn. There's nothing > > quantifyingly palpable here to warrant this. > > I disagree, asm() is a known-bad inlining interface for fundamentally > single-instruction inlines like this one, and there's various > performance benefits to cleaning this up, as evidenced by the benchmark > numbers and analysis in this pending commit: > > 9628d19e91f1 ("x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions") Here's a link for those who'd like to view this via the web: https://lore.kernel.org/all/174188884263.14745.1542926632284353047.tip-bot2@tip-bot2/ Thanks, Ingo