From patchwork Tue Oct 15 02:18:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 13835674 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 1405FCFC501 for ; Tue, 15 Oct 2024 02:26:28 +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-Type: Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=lBshwZIYGFwv2HKPpf3NWkHRe4/cWjAH+tFufgEMU+w=; b=KgJ+vqGVZ1djBPJz95QwBZdgYs V+LC3Ya08JpdMWrc9OrXfEIZVLOr6fHBUDZtEHhx2XtY8Suxpt7YhX2LJyiih83dG/ZmzLjm/6hHR LnCSkHQK/2ySmc5G9rgt9YE+nyCG8/vUCKR7cB2rAbVKwogaS2SYEIXAYZZlT0NACL7mBuPv0LBkn gsOjUDH2vA78Gf2179hN5y/DRqN9XWbdAlJHu1hT0B6Nt3WNe+D+CPephIiHs2Lhf1Mz9FSeukQgQ DL6MbasOPgwgr9n3kQQJxRbI5LVLk06F5Xyv1lXM/S1khSVT67Tn0tQwrMiTpyP/GbYrUoPEOF4Sb 3nDTVM3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t0XGJ-00000006smL-15sy; Tue, 15 Oct 2024 02:26:15 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t0X9T-00000006rby-3qWG for linux-arm-kernel@lists.infradead.org; Tue, 15 Oct 2024 02:19:14 +0000 Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4XSHn61Wg3z2DdfX; Tue, 15 Oct 2024 10:17:46 +0800 (CST) Received: from kwepemd200014.china.huawei.com (unknown [7.221.188.8]) by mail.maildlp.com (Postfix) with ESMTPS id A961B1400D4; Tue, 15 Oct 2024 10:18:58 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) by kwepemd200014.china.huawei.com (7.221.188.8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 15 Oct 2024 10:18:57 +0800 From: Yicong Yang To: , , , , , , , , , , , CC: , , , , , , , , , , , , Subject: [PATCH v6 0/4] Support SMT control on arm64 Date: Tue, 15 Oct 2024 10:18:37 +0800 Message-ID: <20241015021841.35713-1-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 X-Originating-IP: [10.50.165.33] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemd200014.china.huawei.com (7.221.188.8) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241014_191913_084936_1EFA23ED X-CRM114-Status: GOOD ( 10.46 ) 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 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 real ACPI based arm64 server and on ACPI/OF based QEMU VMs. Change since v5: - Drop the dependency on CONFIG_SMP since it's always on on arm64, per Pierre - Avoid potential multiple calls of cpu_smt_set_num_threads() on asymmetric system, per Dietmar - Detect heterogenous SMT topology and issue a warning for partly support, per Pierre - Thanks Dietmar for testing, didn't pickup the tag due to code changes. Thanks testing by Pierre Link: https://lore.kernel.org/linux-arm-kernel/20240806085320.63514-1-yangyicong@huawei.com/ Change since v4: - Provide a default topology_is_primary_thread() in the framework, Per Will Link: https://lore.kernel.org/linux-arm-kernel/20231121092602.47792-1-yangyicong@huawei.com/ Change since v3: - Fix some build and kconfig error reported by kernel test robot Link: https://lore.kernel.org/linux-arm-kernel/20231114040110.54590-1-yangyicong@huawei.com/ Change since v2: - Detect SMT thread number at topology build from ACPI/DT, avoid looping CPUs - Split patches into ACPI/OF/arch_topology path and enable the kconfig for arm64 Link: https://lore.kernel.org/linux-arm-kernel/20231010115335.13862-1-yangyicong@huawei.com/ 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 | 61 +++++++++++++++++++++++++++++ arch/powerpc/include/asm/topology.h | 1 + arch/x86/include/asm/topology.h | 2 +- drivers/base/arch_topology.c | 21 ++++++++++ include/linux/topology.h | 14 +++++++ 6 files changed, 99 insertions(+), 1 deletion(-)