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 7FBF4811E3 for ; Wed, 21 Feb 2024 15:52:04 +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=1708530734; cv=none; b=i88gILgnerFT7OXkf7uL4yT4ev51hgGAAmyKOYLrzJba1WyEynJSg2pIOJGXpUJhsV+E0s8tnr881QHBW8iMOAK+jHNAfvKAQhqise1ebBvQy5xL8yXCZJ3WUuG1BQY45evTGkdBrZ5zECqIznxvWTvMiuxMKvfVU3kcYZos8Oo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708530734; c=relaxed/simple; bh=GOdl8juPhn5nyV5Pl4HF5qwOPyavoNeFUHjkU2P9PL0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=K5ylqpN/LWgZ8ZR7+YlvyhPZ6m/c0HKM26+4AqQI2TBLJMANhQ/Ijaqy9QBdNYSbOnJVcVLYaM0DnqzId0augMcSr6FUCmZ0n4vKqzVHGQ21kO8zeglwosnnj/DApKVh4g2MxgM1b7RFtntBdkv/c+3wZiJQ4uNVsijJiTeDIfM= 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 7123E1007; Wed, 21 Feb 2024 07:52:39 -0800 (PST) Received: from [10.34.100.133] (e126645.nice.arm.com [10.34.100.133]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 112653F73F; Wed, 21 Feb 2024 07:51:58 -0800 (PST) Message-ID: <6843f6b2-4c41-4649-9885-88fde7215e3f@arm.com> Date: Wed, 21 Feb 2024 16:51:57 +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 v1 0/2] support NUMA emulation for genertic arch Content-Language: en-US To: Mike Rapoport , Rongwei Wang Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, gregkh@linuxfoundation.org, rafael@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, luto@kernel.org, teng.ma@linux.alibaba.com References: <20231012024842.99703-1-rongwei.wang@linux.alibaba.com> <20240220113602.6943-1-rongwei.wang@linux.alibaba.com> From: Pierre Gondois In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/21/24 07:12, Mike Rapoport wrote: > On Tue, Feb 20, 2024 at 07:36:00PM +0800, Rongwei Wang wrote: >> A brief introduction >> ==================== >> >> The NUMA emulation can fake more node base on a single >> node system, e.g. > > ... > >> Lastly, it seems not a good choice to realize x86 and other genertic >> archs separately. But it can indeed avoid some architecture related >> APIs adjustments and alleviate future maintenance. > > Why is it a good choice? Copying 1k lines from x86 to a new place and > having to maintain two copies does not sound like a good choice to me. I agree it would be better to avoid duplication and extract the common code from the original x86 implementation. The RFC seemed to go more in this direction. Also NITs: - genertic -> generic - there is a 'ifdef CONFIG_X86' in drivers/base/numa_emulation.c, but the file should not be used by x86 as the arch doesn't set CONFIG_GENERIC_ARCH_NUMA Regards, Pierre > >> The previous RFC link see [1]. >> >> Any advice are welcome, Thanks! >> >> Change log >> ========== >> >> RFC v1 -> v1 >> * add new CONFIG_NUMA_FAKE for genertic archs. >> * keep x86 implementation, realize numa emulation in driver/base/ for >> genertic arch, e.g, arm64. >> >> [1] RFC v1: https://patchwork.kernel.org/project/linux-arm-kernel/cover/20231012024842.99703-1-rongwei.wang@linux.alibaba.com/ >> >> Rongwei Wang (2): >> arch_numa: remove __init for early_cpu_to_node >> numa: introduce numa emulation for genertic arch >> >> drivers/base/Kconfig | 9 + >> drivers/base/Makefile | 1 + >> drivers/base/arch_numa.c | 32 +- >> drivers/base/numa_emulation.c | 909 ++++++++++++++++++++++++++++++++++ >> drivers/base/numa_emulation.h | 41 ++ >> include/asm-generic/numa.h | 2 +- >> 6 files changed, 992 insertions(+), 2 deletions(-) >> create mode 100644 drivers/base/numa_emulation.c >> create mode 100644 drivers/base/numa_emulation.h >> >> -- >> 2.32.0.3.gf3a3e56d6 >> >> >