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 54FFA2BEFEA; Fri, 25 Jul 2025 08:36:07 +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=1753432567; cv=none; b=B/8eU5cycofv+Sl8E6IWZ3qLQPMRFGWwIjTUlKpMgiQGWHdO40N1YIMN4B3bhKrxneu6caCJVgRglkWEOANSD19pL+KAPtoPhui2gZaP+Yv3t6JydqXgF9ltdFJ062TycPPdsQo1bCZgCtF90SXyYQjol94rKfP2bj1Yl8mVPEs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753432567; c=relaxed/simple; bh=cJQS8lbXyn1E0/VlT2bt0JOiVdthkOPUe5hZKO356CM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Yy8SrU7te2/lYPlqU3Q++ZWoJxMiburJiO7eIRaMVV67+nWdXXtg/4lX25fZ2dXe4e95J/9Kipk8RTHrOkwGj5sOREcu2ONBS+cCVH+gGOpQh3pmMkhoxRONt1T7PQqjaRgbC48ZpHdft/M+1/Lp7hbJgtTSPPakh3w64/GtUdM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF7B9C4CEE7; Fri, 25 Jul 2025 08:36:05 +0000 (UTC) Date: Fri, 25 Jul 2025 09:36:03 +0100 From: Catalin Marinas To: Suchit Karunakaran Cc: will@kernel.org, linux-arm-kernel@lists.infradead.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: allow NR_CPUS=1 for non-SMP and adjust default accordingly Message-ID: References: <20250724165639.13926-1-suchitkarunakaran@gmail.com> 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: <20250724165639.13926-1-suchitkarunakaran@gmail.com> On Thu, Jul 24, 2025 at 10:26:39PM +0530, Suchit Karunakaran wrote: > The arm64 Kconfig for NR_CPUS previously required a minimum of 2 CPUs. > This patch changes the minimum allowed CPUs to 1, enabling single-core > non-SMP configurations. Do you have such single-core system? > config NR_CPUS > - int "Maximum number of CPUs (2-4096)" > - range 2 4096 > - default "512" > + int "Maximum number of CPUs (1-4096)" > + range 1 4096 > + default "1" if !SMP > + default "512" if SMP It's been some time since we forced CONFIG_SMP always on for arm64. -- Catalin