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 AD94127FD74 for ; Wed, 17 Dec 2025 15:30:22 +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=1765985422; cv=none; b=R3eBdiPUrKez+UlT3ZDBdVNbm21dQXYzZL1FbE2zafs49cywU5KibzKzR0FnLIxx2QJT2/lQ1GGvIBz++wesA3ry7oFuAZ30QR/sHL8E4xx69t+RUBGaIGy+ZV+BY26pduHGw91D8Mp5Xacv97p7UCCQIhM/9TDcYI2wjJsuGwo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765985422; c=relaxed/simple; bh=m3Nt0gUoK9aooXAul3ONk+se3Q2FtAKEBEEIHKlZ9J0=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=YTq47CGNZHY6YEsLfnqOcMd0RYdNMx5BRgdpz5DDpXR+IwAeHy1YGRjy3oBAWE5rU6q0vAAcA8RXD1VNp82vjvipgCR97ah1RoOhCCFns6mS8beE1RSIT89Wy8Q++7EFIlQws7YWGWevq6tEyfnRbREGDViW7miyAGyyL0M5tcQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pohOHMBD; 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="pohOHMBD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CDF1C4CEF5; Wed, 17 Dec 2025 15:30:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1765985422; bh=m3Nt0gUoK9aooXAul3ONk+se3Q2FtAKEBEEIHKlZ9J0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pohOHMBDRBIiaCMtb1gbyLCPCR8MjWcTTVncfoJUyitdjFmgH2dv7gq5BfZqwhzZ+ 2J8iGATtGPI8hWa3z6pd29ve+ifuj3Vk+Z21VhC15vRygtdFROj2UAx+JaCQVyjtg+ N2Sq+i9s8f/uZEGN0mQf70L7bfQLlgOYmmbzalnPHgWF4YkFngHvpvZOn+uAF+ar0y EVgtU+cN6Q8yXztpoEvVQEpM5PBVqAc2AHdJKMgpC9Ko125eJ8cANMzsHfRyrqYWW+ kU+U30cJfZ6gFSDQgvHeGHKDr9rKN6jOygKxygdOHZylJvO88TtLFFaTtfJxBAb620 BbrmIOfxqZWvQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1vVtTo-0000000DPru-0ESd; Wed, 17 Dec 2025 15:30:20 +0000 Date: Wed, 17 Dec 2025 15:30:19 +0000 Message-ID: <86wm2lm8hg.wl-maz@kernel.org> From: Marc Zyngier To: tanze@kylinos.cn Cc: xry111@xry111.site, james.morse@arm.com, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v1] arm64/mpam: Replace the arm64.nompam parameter with arm64.mpam In-Reply-To: <20251217151159.1076002-1-tanze@kylinos.cn> References: <20251217151159.1076002-1-tanze@kylinos.cn> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: tanze@kylinos.cn, xry111@xry111.site, james.morse@arm.com, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Wed, 17 Dec 2025 15:11:59 +0000, tanze@kylinos.cn wrote: > > From: tanze > > In practical application scenarios, some manufacturers use outdated > firmware and do not add relevant configurations to the kernel command > line during deployment, which will result in system boot failure. > For manufacturers, disabling the MPAM feature by default and > enabling it via additional boot parameters only when required > is a more effective way to ensure compatibility. No. I don't see the need to be overly cooperative with people who do not care about what they ship. If you want to run on broken systems, pass the option that allow you to do so. But don't make it more complicated for people who have HW that actually works. I would rather remove the option to disable MPAM altogether and leave these broken systems completely unsupported. M. -- Without deviation from the norm, progress is not possible.