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 6484ACDB482 for ; Mon, 16 Oct 2023 04:09:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231477AbjJPEJz (ORCPT ); Mon, 16 Oct 2023 00:09:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229478AbjJPEJx (ORCPT ); Mon, 16 Oct 2023 00:09:53 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8E77C5 for ; Sun, 15 Oct 2023 21:09:50 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id d2e1a72fcca58-6bd96cfb99cso517502b3a.2 for ; Sun, 15 Oct 2023 21:09:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697429390; x=1698034190; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=wGM0mRZxvBtzql9FwK0jFJh47x4n6KkdzlqXBUfZfHs=; b=lqmEvE9T64HUDNRIS8ka06+SHjzROuIprkmBczNwNBf7P/dSnOMVRakU1yTRBeVp4D u8x+hJYFTxo/Uo731JZ5GI9/fhGhqLv3dwEiTiV4T3/Bc/V9/XmEWiIx5pmeqXScQ1hV xIgUR44ixvZFw6MmQbxg6rW3faBq0oODjq8BmLbHC760xkj8eqT8WB9eW5h7NHHfKof3 mVT4kEQUekNpJDFnALwJ43CrvDUfNQMipVMhbyDmkUOievMhO6EN0A2X1XtMgPwyJhnL A3QYxMUftM3yxil9ncHqBXn8829CW27TsR9BX3egqOg6i6A/3705OUHhFW50UcAwzMTm WxrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697429390; x=1698034190; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=wGM0mRZxvBtzql9FwK0jFJh47x4n6KkdzlqXBUfZfHs=; b=Um1dA7ihGVKW171KZcGNXRSwWsyfjo/DiXgYuPk76230Dq+XYPfoKIL4Ev9R8xyRNg F/aQ0y5ks3bQzfwhpYzDjce0R1dNj1O/4EGjEonaxzZcft6mMsrkmMYCl7f4XGN5HmKA rEmGt760oJ2cenfD5Ejd10rlTrj0hcQ6M5+ChO3I2O+h80lb/xvGryr1AUJn5M/uTmAm Ybs54nV71nhAO2hb/OAOB/C9eZ1RSQmBjuRaTMalT0eRGt8LmQA/2qD8aNb52C84elAD 7MPh64/rB4KUB9Mz2QoUjzZWl+C4fTqmyk41SsoH3ohEm3aU3Umygi0c/WH7lLEM1L58 9XOw== X-Gm-Message-State: AOJu0Yxaa7blL9obAMSDuQ1xYgHzNtm/HpLyRQScXcz4n8QH20H+51id A2EA3zi+6a0aCTD00uRsXJQ= X-Google-Smtp-Source: AGHT+IHAbPbjF+cqVgpdkO+Soafo+YgWVpt5DgzO/plnHTgAw1Zg8d7wh2s4hvd6jPM2I7y35acBqQ== X-Received: by 2002:a05:6a00:2e20:b0:68e:42c9:74e0 with SMTP id fc32-20020a056a002e2000b0068e42c974e0mr33993929pfb.3.1697429390290; Sun, 15 Oct 2023 21:09:50 -0700 (PDT) Received: from [10.84.155.153] ([203.208.167.147]) by smtp.gmail.com with ESMTPSA id b184-20020a62cfc1000000b0068c006dd5c1sm2605085pfg.115.2023.10.15.21.09.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 15 Oct 2023 21:09:49 -0700 (PDT) Message-ID: <8f506561-44f7-a243-f0cc-59543f487e4d@gmail.com> Date: Mon, 16 Oct 2023 12:09:42 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH] mm: page_alloc: don't allocate page from memoryless nodes Content-Language: en-US To: Mike Rapoport Cc: Michal Hocko , David Hildenbrand , Qi Zheng , Vlastimil Babka , akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Teng Hu , Matthew Wilcox , Mel Gorman , Oscar Salvador , Muchun Song , x86@kernel.org References: <67240e55-af49-f20a-2b4b-b7d574cd910d@gmail.com> <22f0e262-982e-ea80-e52a-a3c924b31d58@redhat.com> <4386151c-0328-d207-9a71-933ef61817f9@redhat.com> From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mike, On 2023/2/15 17:30, Mike Rapoport wrote: [...] > > How about we try this: > > From b670120bcacd3fe34a40d7179c70ca2ab69279e0 Mon Sep 17 00:00:00 2001 > From: "Mike Rapoport (IBM)" > Date: Wed, 15 Feb 2023 11:12:18 +0200 > Subject: [PATCH] x86/mm: drop 4MB restriction on minimal NUMA node size > > Qi Zheng reports crashes in a production environment and provides a > simplified example as a reproducer: > > For example, if we use qemu to start a two NUMA node kernel, > one of the nodes has 2M memory (less than NODE_MIN_SIZE), > and the other node has 2G, then we will encounter the > following panic: > > [ 0.149844] BUG: kernel NULL pointer dereference, address: 0000000000000000 > [ 0.150783] #PF: supervisor write access in kernel mode > [ 0.151488] #PF: error_code(0x0002) - not-present page > <...> > [ 0.156056] RIP: 0010:_raw_spin_lock_irqsave+0x22/0x40 > <...> > [ 0.169781] Call Trace: > [ 0.170159] > [ 0.170448] deactivate_slab+0x187/0x3c0 > [ 0.171031] ? bootstrap+0x1b/0x10e > [ 0.171559] ? preempt_count_sub+0x9/0xa0 > [ 0.172145] ? kmem_cache_alloc+0x12c/0x440 > [ 0.172735] ? bootstrap+0x1b/0x10e > [ 0.173236] bootstrap+0x6b/0x10e > [ 0.173720] kmem_cache_init+0x10a/0x188 > [ 0.174240] start_kernel+0x415/0x6ac > [ 0.174738] secondary_startup_64_no_verify+0xe0/0xeb > [ 0.175417] > [ 0.175713] Modules linked in: > [ 0.176117] CR2: 0000000000000000 > > The crashes happen because of inconsistency between nodemask that has > nodes with less than 4MB as memoryless and the actual memory fed into > core mm. > > The commit 9391a3f9c7f1 ("[PATCH] x86_64: Clear more state when ignoring > empty node in SRAT parsing") that introduced minimal size of a NUMA node > does not explain why a node size cannot be less than 4MB and what boot > failures this restriction might fix. > > Since then a lot has changed and core mm won't confuse badly about small > node sizes. > > Drop the limitation for the minimal node size. > > Link: https://lore.kernel.org/all/20230212110305.93670-1-zhengqi.arch@bytedance.com/ > Signed-off-by: Mike Rapoport (IBM) > --- > arch/x86/include/asm/numa.h | 7 ------- > arch/x86/mm/numa.c | 7 ------- > 2 files changed, 14 deletions(-) What's the current progress on this patch? This patch doesn't seem to be merged into any trees. Did I miss something? Thanks, Qi > > diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h > index e3bae2b60a0d..ef2844d69173 100644 > --- a/arch/x86/include/asm/numa.h > +++ b/arch/x86/include/asm/numa.h > @@ -12,13 +12,6 @@ > > #define NR_NODE_MEMBLKS (MAX_NUMNODES*2) > > -/* > - * Too small node sizes may confuse the VM badly. Usually they > - * result from BIOS bugs. So dont recognize nodes as standalone > - * NUMA entities that have less than this amount of RAM listed: > - */ > -#define NODE_MIN_SIZE (4*1024*1024) > - > extern int numa_off; > > /* > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > index 2aadb2019b4f..55e3d895f15c 100644 > --- a/arch/x86/mm/numa.c > +++ b/arch/x86/mm/numa.c > @@ -601,13 +601,6 @@ static int __init numa_register_memblks(struct numa_meminfo *mi) > if (start >= end) > continue; > > - /* > - * Don't confuse VM with a node that doesn't have the > - * minimum amount of memory: > - */ > - if (end && (end - start) < NODE_MIN_SIZE) > - continue; > - > alloc_node_data(nid); > } >