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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 805B7C4CEC6 for ; Sun, 15 Sep 2019 06:14:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56BA920830 for ; Sun, 15 Sep 2019 06:14:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726205AbfIOGOB (ORCPT ); Sun, 15 Sep 2019 02:14:01 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:2269 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725497AbfIOGOB (ORCPT ); Sun, 15 Sep 2019 02:14:01 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id EBDFD36DDAEE5ECE5E61; Sun, 15 Sep 2019 14:13:56 +0800 (CST) Received: from [127.0.0.1] (10.74.191.121) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.439.0; Sun, 15 Sep 2019 14:13:52 +0800 Subject: Re: [PATCH v3 7/8] mips: numa: make node_to_cpumask_map() NUMA_NO_NODE aware for mips To: Mike Rapoport CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , References: <1568283334-178380-1-git-send-email-linyunsheng@huawei.com> <1568283334-178380-8-git-send-email-linyunsheng@huawei.com> <20190915054901.GC11429@linux.ibm.com> From: Yunsheng Lin Message-ID: <938be3af-ece4-7f5f-34d6-f949ee2a3d32@huawei.com> Date: Sun, 15 Sep 2019 14:13:51 +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: <20190915054901.GC11429@linux.ibm.com> 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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/9/15 13:49, Mike Rapoport wrote: > Hi, > > On Thu, Sep 12, 2019 at 06:15:33PM +0800, Yunsheng Lin wrote: >> When passing the return value of dev_to_node() to cpumask_of_node() >> without checking the node id if the 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. >> >> Since this arch was already NUMA_NO_NODE aware, this patch only changes >> it to return cpu_online_mask and use NUMA_NO_NODE instead of "-1". >> >> [1] https://lore.kernel.org/patchwork/patch/1125789/ >> Signed-off-by: Yunsheng Lin >> Suggested-by: Michal Hocko >> --- >> 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. >> --- >> arch/mips/include/asm/mach-ip27/topology.h | 4 ++-- > > Nit: the subject says "mips:", but this patch only touches sgi-ip27 and > loongson is updated as a separate patch. I don't see why both patches > cannot be merged. Moreover, the whole set can be made as a single patch, > IMHO. Thanks for reviewing. As this patchset touches a few files, which may has different maintainer. I am not sure if a separate patch for different arch will make the merging process easy, or a single patch will make the merging process easy? It can be made as a single patch if a single patch will make the merging process easy. > >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/mips/include/asm/mach-ip27/topology.h b/arch/mips/include/asm/mach-ip27/topology.h >> index 965f079..04505e6 100644 >> --- a/arch/mips/include/asm/mach-ip27/topology.h >> +++ b/arch/mips/include/asm/mach-ip27/topology.h >> @@ -15,8 +15,8 @@ struct cpuinfo_ip27 { >> extern struct cpuinfo_ip27 sn_cpu_info[NR_CPUS]; >> >> #define cpu_to_node(cpu) (sn_cpu_info[(cpu)].p_nodeid) >> -#define cpumask_of_node(node) ((node) == -1 ? \ >> - cpu_all_mask : \ >> +#define cpumask_of_node(node) ((node) == NUMA_NO_NODE ? \ >> + cpu_online_mask : \ >> &hub_data(node)->h_cpus) >> struct pci_bus; >> extern int pcibus_to_node(struct pci_bus *); >> -- >> 2.8.1 >> >