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 69DF3C433EF for ; Tue, 19 Apr 2022 08:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350178AbiDSI4v (ORCPT ); Tue, 19 Apr 2022 04:56:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345296AbiDSI4t (ORCPT ); Tue, 19 Apr 2022 04:56:49 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8180220D5 for ; Tue, 19 Apr 2022 01:54:06 -0700 (PDT) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4KjHbT6Y5vzFqSY; Tue, 19 Apr 2022 16:51:33 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 19 Apr 2022 16:54:03 +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; Tue, 19 Apr 2022 16:54:03 +0800 Message-ID: <477dcc83-4298-b7e4-3a6a-c8fa23b27d01@huawei.com> Date: Tue, 19 Apr 2022 16:54:02 +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: Andrew Morton CC: 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> <1407c3bb-89c4-ae11-7b09-d42115ab693e@huawei.com> <20220418214040.419a2e17254eb33f68f94b59@linux-foundation.org> From: Kefeng Wang In-Reply-To: <20220418214040.419a2e17254eb33f68f94b59@linux-foundation.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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 2022/4/19 12:40, Andrew Morton wrote: > On Sat, 16 Apr 2022 09:21:45 +0800 Kefeng Wang wrote: > >> 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 >> > Does the v4 patch address the issues which were raised in this thread? Yes， v4 has fix this. > > > --- a/mm/hugetlb.c~hugetlb-fix-wrong-use-of-nr_online_nodes-v4 > +++ a/mm/hugetlb.c > @@ -2986,8 +2986,6 @@ int __alloc_bootmem_huge_page(struct hst > struct huge_bootmem_page *m = NULL; /* initialize for clang */ > int nr_nodes, node; > > - if (nid != NUMA_NO_NODE && !node_online(nid)) > - return 0; > /* do node specific alloc */ > if (nid != NUMA_NO_NODE) { > m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), > @@ -4174,7 +4172,7 @@ static int __init hugepages_setup(char * > pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); > return 0; > } > - if (!node_online(tmp)) > + if (tmp >= MAX_NUMNODES || !node_online(tmp)) > goto invalid; > node = array_index_nospec(tmp, MAX_NUMNODES); > p += count + 1; > _ > > .