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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10759C433EF for ; Sat, 16 Apr 2022 02:06:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229587AbiDPCIZ (ORCPT ); Fri, 15 Apr 2022 22:08:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229683AbiDPCGO (ORCPT ); Fri, 15 Apr 2022 22:06:14 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39451F3A for ; Fri, 15 Apr 2022 19:00:44 -0700 (PDT) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KgFl70tV3zfYpJ; Sat, 16 Apr 2022 09:21:07 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 16 Apr 2022 09:21:46 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 16 Apr 2022 09:21:45 +0800 Message-ID: <1407c3bb-89c4-ae11-7b09-d42115ab693e@huawei.com> Date: Sat, 16 Apr 2022 09:21:45 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.5.1 Subject: Re: [PATCH v3 1/4] hugetlb: Fix wrong use of nr_online_nodes Content-Language: en-US To: Peng Liu , , , , , , , , , References: <20220413032915.251254-1-liupeng256@huawei.com> <20220413032915.251254-2-liupeng256@huawei.com> <20220415020927.x7ylevbd5uaevfyt@offworld> <08896d0c-8821-000e-4cc2-9e64beda167f@huawei.com> From: Kefeng Wang In-Reply-To: <08896d0c-8821-000e-4cc2-9e64beda167f@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/4/15 13:41, Kefeng Wang wrote: > > On 2022/4/15 10:09, Davidlohr Bueso wrote: >> On Wed, 13 Apr 2022, Peng Liu wrote: >> >>> Certain systems are designed to have sparse/discontiguous nodes. In >>> this case, nr_online_nodes can not be used to walk through numa node. >>> Also, a valid node may be greater than nr_online_nodes. >>> >>> However, in hugetlb, it is assumed that nodes are contiguous. Recheck >>> all the places that use nr_online_nodes, and repair them one by one. >>> >>> Suggested-by: David Hildenbrand >>> Fixes: 4178158ef8ca ("hugetlbfs: fix issue of preallocation of >>> gigantic pages can't work") >>> Fixes: b5389086ad7b ("hugetlbfs: extend the definition of hugepages >>> parameter to support node allocation") >>> Fixes: e79ce9832316 ("hugetlbfs: fix a truncation issue in hugepages >>> parameter") >>> Fixes: f9317f77a6e0 ("hugetlb: clean up potential spectre issue >>> warnings") >>> Signed-off-by: Peng Liu >>> Reviewed-by: Baolin Wang >>> Reviewed-by: Mike Kravetz >> >> Reviewed-by: Davidlohr Bueso >> >> ... but >> >>> --- >>> mm/hugetlb.c | 12 ++++++------ >>> 1 file changed, 6 insertions(+), 6 deletions(-) >>> >>> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >>> index b34f50156f7e..5b5a2a5a742f 100644 >>> --- a/mm/hugetlb.c >>> +++ b/mm/hugetlb.c >>> @@ -2979,7 +2979,7 @@ int __alloc_bootmem_huge_page(struct hstate >>> *h, int nid) >>>     struct huge_bootmem_page *m = NULL; /* initialize for clang */ >>>     int nr_nodes, node; >>> >>> -    if (nid != NUMA_NO_NODE && nid >= nr_online_nodes) >>> +    if (nid != NUMA_NO_NODE && !node_online(nid)) >> >> afaict null_blk could also use this, actually the whole thing wants a >> helper - node_valid()? >> > This one should be unnecessary, and this patch looks has a bug, > > if a very nid passed to node_online(), it may crash,  could you > re-check it, > > see my changes below, > > 1) add tmp check against MAX_NUMNODES before node_online() check, > >     and move it after get tmp in hugepages_setup() , this could cover > both per-node alloc and normal alloc sorry，for normal alloc, tmp is the number of huge pages, we don't  need the movement,   only add tmp >= MAX_NUMNODES is ok > > 2) due to for_each_online_node() usage, we can drop additional check > of nid in __alloc_bootmem_huge_page() >