From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ms.lwn.net (ms.lwn.net [45.79.88.28]) (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 88A103B27FB; Fri, 15 May 2026 14:26:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.79.88.28 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778855214; cv=none; b=kCZpQy4K/tg1kBNwQpGShNZI1Gk7Ih5NCcNwjenigI1pQmB2eXbiEt33nB9IVtJijb2UKaRUlI48Z7Ms2CJKUPE28xn0IJo6dvWCVrq4diUGFWUseD9QfVnw58QZCygAoAu977IK3ZtCj3AVc2bL96H8QyVpWmiH25AfsKirVFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778855214; c=relaxed/simple; bh=l4sUqsfEqPrWGz3d7rrX5FyMiR6PrxVNqr5HYPnzGeY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=YapFJTqJ6XVVmzsdTWDmtp/A/ylimEoW86uLAqzym6ZTB/FAar371eg8CtMZs8aLkkwjNqwNDVaiCOvs1q4uYPdmp7sDA8yoG8xYXrxHZeweGZGg8nHTaiPv/h3j7kfeoNIMbZiZ0LKYcExZObutaFRPjmTvpH072jyBgi42Fyo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net; spf=pass smtp.mailfrom=lwn.net; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b=Aa4DPsKK; arc=none smtp.client-ip=45.79.88.28 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lwn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lwn.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lwn.net header.i=@lwn.net header.b="Aa4DPsKK" DKIM-Filter: OpenDKIM Filter v2.11.0 ms.lwn.net D3505410B5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lwn.net; s=20201203; t=1778855213; bh=UBVn+424J8p1Gqvfvb04655le/ltoFHH0wfexrn4DoI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Aa4DPsKKnpwiXjMKfYykVgnz8re5Vp3lW53My7oe7pkDs5IuF/qFIRmHgkuBAiBvz LtGMkfXn6B4hM2rjgZCk1lWTV5oRz8eJuNbGYVdY84PTTEuNePZxJGI6OaP3UbwWip wDYJl6WkOBaNaY0KbQniNdhbAnYy5d8Sf2pSh2T9jEvbXyIvTROZOAe32Pz4qTCqYu BY2wJqZp9Nra+PwdROUSa2X3EaTuP+60fLN8f6nvLhakZvamygvDc3QhQp4OsPX+H8 w1V5X2wo2Hi/KhdPJM5sck6e5AeD23z3xedkT4jlzyDzEO4hnpWhY3XPZ6iISafG/G YmZ8Gw3UUte8Q== Received: from localhost (unknown [IPv6:2601:280:4600:27b:67c:16ff:fe81:5f9b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id D3505410B5; Fri, 15 May 2026 14:26:52 +0000 (UTC) From: Jonathan Corbet To: Jinjie Ruan , skhan@linuxfoundation.org, akpm@linux-foundation.org, bp@alien8.de, rdunlap@infradead.org, pmladek@suse.com, pawan.kumar.gupta@linux.intel.com, feng.tang@linux.alibaba.com, dapeng1.mi@linux.intel.com, kees@kernel.org, elver@google.com, paulmck@kernel.org, lirongqing@baidu.com, safinaskar@gmail.com, bhelgaas@google.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, skelley@nvidia.com Cc: ruanjinjie@huawei.com Subject: Re: [PATCH] docs: Update nosmt support for arm64 In-Reply-To: <20260417032540.3720627-1-ruanjinjie@huawei.com> References: <20260417032540.3720627-1-ruanjinjie@huawei.com> Date: Fri, 15 May 2026 08:26:51 -0600 Message-ID: <871pfcrbo4.fsf@trenco.lwn.net> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Jinjie Ruan writes: > commit eed4583bcf9a6 ("arm64: Kconfig: Enable HOTPLUG_SMT") enable > HOTPLUG_SMT for SMT control for arm64, but the documentation was > not updated accordingly to reflect that ARM64 now supports control SMT > via boot parameter and sysfs knobs: > > 1. Boot parameters: > > nosmt: Disable SMT, can be enabled via sysfs knobs. > nosmt=force: Disable SMT, cannot be enabled via sysfs knobs. > > 2. Runtime sysfs controls: > > Write "on", "off", "forceoff" or the number of SMT threads (1, 2, ...) > to /sys/devices/system/cpu/smt/control. > > Signed-off-by: Jinjie Ruan > --- > Documentation/admin-guide/kernel-parameters.txt | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index cb850e5290c2..6a73eb5abae9 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -4661,7 +4661,7 @@ Kernel parameters > nosmt [KNL,MIPS,PPC,EARLY] Disable symmetric multithreading (SMT). > Equivalent to smt=1. > > - [KNL,LOONGARCH,X86,PPC,S390] Disable symmetric multithreading (SMT). > + [KNL,LOONGARCH,X86,ARM64,PPC,S390] Disable symmetric multithreading (SMT). Applied, thanks. jon