From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7D8E6C19776 for ; Fri, 28 Feb 2025 11:59:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=VsbgSY0KdK4WCEQoWD7P7DX8QHItEdhrghN3ri4wOyw=; b=DblAzBS8hNfHQ/m+bm33vDsOCd fTDtG7gUF8mxaXB/7tAunzycWNbOeRqPT+1178l2VLv3kTxwrsfY1gL9buxsCB955Av92GAbN4RYA lvkYBpQqL4n4eoBBmfJVpC6in11iq766e+ns0pFh/eo8PznRg20r6WKnSftIYLJ7Ulf40vpQnORjt ++yB15d9JG5zVfGRidjiZ9v9awQimT1kNn0liWPpJP0a6Rnfq5ejOReVA3lZUZN0S/8ltMdl5u9pU 0KQDWXSJSfs7zV9MPxPrlTJlKgfwWuQXr9SWdrS9Y/LirNmdoazWnM4SebvQhSB+YhDX+NLM/tmXy Ynlc0rLQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tnz1s-0000000ApT8-3NyS; Fri, 28 Feb 2025 11:59:44 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tnyHx-0000000Ai5g-2RGp for linux-arm-kernel@lists.infradead.org; Fri, 28 Feb 2025 11:12:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4566D1063; Fri, 28 Feb 2025 03:12:32 -0800 (PST) Received: from [192.168.178.115] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 92FD63F673; Fri, 28 Feb 2025 03:12:12 -0800 (PST) Message-ID: Date: Fri, 28 Feb 2025 12:12:02 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 0/4] Support SMT control on arm64 To: Yicong Yang , catalin.marinas@arm.com, will@kernel.org, sudeep.holla@arm.com, tglx@linutronix.de, peterz@infradead.org, mpe@ellerman.id.au, linux-arm-kernel@lists.infradead.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, pierre.gondois@arm.com Cc: linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, morten.rasmussen@arm.com, msuchanek@suse.de, gregkh@linuxfoundation.org, rafael@kernel.org, jonathan.cameron@huawei.com, prime.zeng@hisilicon.com, linuxarm@huawei.com, yangyicong@hisilicon.com, xuwei5@huawei.com, guohanjun@huawei.com, sshegde@linux.ibm.com References: <20250218141018.18082-1-yangyicong@huawei.com> From: Dietmar Eggemann Content-Language: en-US In-Reply-To: <20250218141018.18082-1-yangyicong@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250228_031217_666998_13EA7257 X-CRM114-Status: GOOD ( 10.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 18/02/2025 15:10, Yicong Yang wrote: > From: Yicong Yang > > The core CPU control framework supports runtime SMT control which > is not yet supported on arm64. Besides the general vulnerabilities > concerns we want this runtime control on our arm64 server for: > > - better single CPU performance in some cases > - saving overall power consumption > > This patchset implements it in the following aspects: > > - Provides a default topology_is_primary_thread() > - support retrieve SMT thread number on OF based system > - support retrieve SMT thread number on ACPI based system > - select HOTPLUG_SMT for arm64 > > Tests has been done on our ACPI based arm64 server and on ACPI/OF > based QEMU VMs. [...] > Yicong Yang (4): > cpu/SMT: Provide a default topology_is_primary_thread() > arch_topology: Support SMT control for OF based system > arm64: topology: Support SMT control on ACPI based system > arm64: Kconfig: Enable HOTPLUG_SMT > > arch/arm64/Kconfig | 1 + > arch/arm64/kernel/topology.c | 66 +++++++++++++++++++++++++++++ > arch/powerpc/include/asm/topology.h | 1 + > arch/x86/include/asm/topology.h | 2 +- > drivers/base/arch_topology.c | 27 ++++++++++++ > include/linux/topology.h | 22 ++++++++++ > 6 files changed, 118 insertions(+), 1 deletion(-) With the review comments on the individual patches [0-3]/4: Reviewed-by: Dietmar Eggemann