From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 4C4D96B0033 for ; Wed, 29 Nov 2017 08:26:54 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id m9so2462748pff.0 for ; Wed, 29 Nov 2017 05:26:54 -0800 (PST) Received: from huawei.com (szxga04-in.huawei.com. [45.249.212.190]) by mx.google.com with ESMTPS id u10si1268238plu.512.2017.11.29.05.26.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 Nov 2017 05:26:53 -0800 (PST) Message-ID: <5A1EB57B.2080101@huawei.com> Date: Wed, 29 Nov 2017 21:26:19 +0800 From: zhong jiang MIME-Version: 1.0 Subject: Re: [PATCH] x86/numa: move setting parse numa node to num_add_memblk References: <1511946807-22024-1-git-send-email-zhongjiang@huawei.com> <20171129120328.dfbr26o4wsjpwct3@dhcp22.suse.cz> <5A1EAAF5.4040602@huawei.com> <20171129130158.hji24remijkaoydb@dhcp22.suse.cz> In-Reply-To: <20171129130158.hji24remijkaoydb@dhcp22.suse.cz> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, lenb@kernel.org, akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, richard.weiyang@gmail.com, pombredanne@nexb.com, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org On 2017/11/29 21:01, Michal Hocko wrote: > On Wed 29-11-17 20:41:25, zhong jiang wrote: >> On 2017/11/29 20:03, Michal Hocko wrote: >>> On Wed 29-11-17 17:13:27, zhong jiang wrote: >>>> Currently, Arm64 and x86 use the common code wehn parsing numa node >>>> in a acpi way. The arm64 will set the parsed node in numa_add_memblk, >>>> but the x86 is not set in that , then it will result in the repeatly >>>> setting. And the parsed node maybe is unreasonable to the system. >>>> >>>> we would better not set it although it also still works. because the >>>> parsed node is unresonable. so we should skip related operate in this >>>> node. This patch just set node in various architecture individually. >>>> it is no functional change. >>> I really have hard time to understand what you try to say above. Could >>> you start by the problem description and then how you are addressing it? >> I am so sorry for that. I will make the issue clear. >> >> Arm64 get numa information through acpi. The code flow is as follows. >> >> arm64_acpi_numa_init >> acpi_parse_memory_affinity >> acpi_numa_memory_affinity_init >> numa_add_memblk(nid, start, end); //it will set node to numa_nodes_parsed successfully. >> node_set(node, numa_nodes_parsed); // numa_add_memblk had set that. it will repeat. >> >> the root cause is that X86 parse numa also go through above code. and arch-related >> numa_add_memblk is not set the parsed node to numa_nodes_parsed. it need >> additional node_set(node, numa_parsed) to handle. therefore, the issue will be introduced. >> > No it is not much more clear. I would have to go and re-study the whole > code flow to see what you mean here. So you could simply state what _the > issue_ is? How can user observe it and what are the consequences? The patch do not fix a real issue. it is a cleanup. because the acpi code is public, I find they are messy between Arch64 and X86 when parsing numa message . therefore, I try to make the code more clear between them. Thanks zhongjiang > Sorry for my laziness, I could go and read the code but the primary > point of the changelog is to be _clear_ about the problem and the fix. > Call paths can help reviewers but the scope should be clear even without > them. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org