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 EF2A5C433F5 for ; Tue, 19 Apr 2022 04:40:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347721AbiDSEn1 (ORCPT ); Tue, 19 Apr 2022 00:43:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233079AbiDSEn0 (ORCPT ); Tue, 19 Apr 2022 00:43:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 993B322B3F for ; Mon, 18 Apr 2022 21:40:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 54D2CB810FD for ; Tue, 19 Apr 2022 04:40:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B313BC385A5; Tue, 19 Apr 2022 04:40:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1650343242; bh=uWEDIFY5XKIDC4ytCvtAvvDemC0uJmsZ3J7/cOGseE4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=wXUa2JPfjIbzdwqGl4yeLF6mkOHOiNVK4PCNhA5t+O4GbLdtzLX2vMjlyq4YgEdmb cqOllu4AJPMHJFpC1gRRHUFa9nOr6e2g5JRBQzMLLPDTHY0fceGDpJnVe6Tkcetnul Kqv7toiheDxv0Jh2r7ozhGkgzT/+AjzKd0B2Ki58= Date: Mon, 18 Apr 2022 21:40:40 -0700 From: Andrew Morton To: Kefeng Wang Cc: Peng Liu , , , , , , , , Subject: Re: [PATCH v3 1/4] hugetlb: Fix wrong use of nr_online_nodes Message-Id: <20220418214040.419a2e17254eb33f68f94b59@linux-foundation.org> In-Reply-To: <1407c3bb-89c4-ae11-7b09-d42115ab693e@huawei.com> 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> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? --- 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; _