From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BCDE826038A for ; Fri, 28 Feb 2025 11:12:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740741139; cv=none; b=HnlY4vU3wqYRS9WSmftuD+iqkZgt5SI3dujUeej0+xnBFdFlZkwyaQv9fMm1Y1vs4VBM4H2xNqCpKByyfn+GWLx/oEgf+HpW58XuFbwDMbXaFqjsjfCNKfMxeDcvXuWvjBWznlszO32kqVSRhkKV4a0a9UrR43tcfgxyIj1KosU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740741139; c=relaxed/simple; bh=9lQ103/GC3slcRVO1G6NpdTptAg8raUxv7XB6+kJ7bE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fuf/guWDVlas4ESiLgvUEoOsevmOLvqdVGSXkkdjkAEo9JGo8vG6z0S1nq5Ge5H/zi2ZwzGMVZPpIchmuLx+y2H07s1hr6Ub7bzPc+3DIjGy9PeMEJySZTtYoFdXWXmi8mnN13YQDL1Bmk3vYI095m5u+7Ax9hGuG/dCkp9iFn0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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