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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76D24C3A5A2 for ; Mon, 23 Sep 2019 02:33:07 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A9066206C2 for ; Mon, 23 Sep 2019 02:33:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9066206C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46c7f80DQXzDqLX for ; Mon, 23 Sep 2019 12:33:04 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=huawei.com (client-ip=45.249.212.190; helo=huawei.com; envelope-from=linyunsheng@huawei.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from huawei.com (szxga04-in.huawei.com [45.249.212.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46c7c80JlMzDqH1 for ; Mon, 23 Sep 2019 12:31:17 +1000 (AEST) Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 7E713D4AB52CFE913988; Mon, 23 Sep 2019 10:31:11 +0800 (CST) Received: from [127.0.0.1] (10.74.191.121) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Mon, 23 Sep 2019 10:31:09 +0800 Subject: Re: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO_NODE aware To: Paul Burton References: <1568724534-146242-1-git-send-email-linyunsheng@huawei.com> <20190921223818.sodqc2ui7mpt7ig5@pburton-laptop> From: Yunsheng Lin Message-ID: <57b3f143-f83b-f96a-de7b-1eccecc81dbb@huawei.com> Date: Mon, 23 Sep 2019 10:31:08 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20190921223818.sodqc2ui7mpt7ig5@pburton-laptop> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.74.191.121] X-CFilter-Loop: Reflected X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "dalias@libc.org" , "linux-sh@vger.kernel.org" , "peterz@infradead.org" , "catalin.marinas@arm.com" , "dave.hansen@linux.intel.com" , "heiko.carstens@de.ibm.com" , "jiaxun.yang@flygoat.com" , "linux-mips@vger.kernel.org" , "mwb@linux.vnet.ibm.com" , "paulus@samba.org" , "hpa@zytor.com" , "sparclinux@vger.kernel.org" , "chenhc@lemote.com" , "will@kernel.org" , "cai@lca.pw" , "linux-s390@vger.kernel.org" , "ysato@users.sourceforge.jp" , "x86@kernel.org" , "rppt@linux.ibm.com" , "borntraeger@de.ibm.com" , "dledford@redhat.com" , "mingo@redhat.com" , "jeffrey.t.kirsher@intel.com" , "jhogan@kernel.org" , "mattst88@gmail.com" , "len.brown@intel.com" , "gor@linux.ibm.com" , "anshuman.khandual@arm.com" , "gregkh@linuxfoundation.org" , "bp@alien8.de" , "luto@kernel.org" , "tglx@linutronix.de" , "mhocko@kernel.org" , "naveen.n.rao@linux.vnet.ibm.com" , "linux-arm-kernel@lists.infradead.org" , "rth@twiddle.net" , "axboe@kernel.dk" , "linuxppc-dev@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" , "ralf@linux-mips.org" , "tbogendoerfer@suse.de" , "linux-alpha@vger.kernel.org" , "rafael@kernel.org" , "ink@jurassic.park.msu.ru" , "akpm@linux-foundation.org" , "robin.murphy@arm.com" , "davem@davemloft.net" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 2019/9/22 6:38, Paul Burton wrote: > Hi Yunsheng, > > On Tue, Sep 17, 2019 at 08:48:54PM +0800, Yunsheng Lin wrote: >> When passing the return value of dev_to_node() to cpumask_of_node() >> without checking if the device's node id is NUMA_NO_NODE, there is >> global-out-of-bounds detected by KASAN. >> >> From the discussion [1], NUMA_NO_NODE really means no node affinity, >> which also means all cpus should be usable. So the cpumask_of_node() >> should always return all cpus online when user passes the node id as >> NUMA_NO_NODE, just like similar semantic that page allocator handles >> NUMA_NO_NODE. >> >> But we cannot really copy the page allocator logic. Simply because the >> page allocator doesn't enforce the near node affinity. It just picks it >> up as a preferred node but then it is free to fallback to any other numa >> node. This is not the case here and node_to_cpumask_map will only restrict >> to the particular node's cpus which would have really non deterministic >> behavior depending on where the code is executed. So in fact we really >> want to return cpu_online_mask for NUMA_NO_NODE. >> >> Also there is a debugging version of node_to_cpumask_map() for x86 and >> arm64, which is only used when CONFIG_DEBUG_PER_CPU_MAPS is defined, this >> patch changes it to handle NUMA_NO_NODE as normal node_to_cpumask_map(). >> >> [1] https://lore.kernel.org/patchwork/patch/1125789/ >> Signed-off-by: Yunsheng Lin >> Suggested-by: Michal Hocko >> Acked-by: Michal Hocko > > If you end up sending another revision then I think it would be worth > replacing -1 with NUMA_NO_NODE in > arch/mips/include/asm/mach-ip27/topology.h for consistency, but in any > case: Perhaps it is better to replace -1 with NUMA_NO_NODE along with cpu_all_mask -> cpu_online_mask change if the cpu_all_mask -> cpu_online_mask change is reasonable. Anyway, will do that if there is another version needed. > > Acked-by: Paul Burton # MIPS bits Thanks for that. > > Thanks, > Paul > >> --- >> V6: Drop the cpu_all_mask -> cpu_online_mask change for it seems a >> little controversial, may need deeper investigation, and rebased >> on the latest linux-next. >> V5: Drop unsigned "fix" change for x86/arm64, and change comment log >> according to Michal's comment. >> V4: Have all these changes in a single patch. >> V3: Change to only handle NUMA_NO_NODE, and return cpu_online_mask >> for NUMA_NO_NODE case, and change the commit log to better justify >> the change. >> V2: make the node id checking change to other arches too. >> --- >> arch/arm64/include/asm/numa.h | 3 +++ >> arch/arm64/mm/numa.c | 3 +++ >> arch/mips/include/asm/mach-loongson64/topology.h | 4 +++- >> arch/s390/include/asm/topology.h | 3 +++ >> arch/x86/include/asm/topology.h | 3 +++ >> arch/x86/mm/numa.c | 3 +++ >> 6 files changed, 18 insertions(+), 1 deletion(-) > > . >