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=-6.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 B2946C43387 for ; Mon, 14 Jan 2019 11:48:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8243720659 for ; Mon, 14 Jan 2019 11:48:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547466539; bh=NvrUyPy0A3uWaEMDNX4FDMV+k0O809Dj1GBEiuyKzGg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=rphapupRlPlnydgUyIUDbHaSfePNV2mQ9aBr2F33Pn27W41jROf86K0xOmp2cL7x6 M6PU/8ERzpFkrpy1L/P/SsEzdR+YU8YeOtyQJxYDWtyZBFPeS3b6J19xy4t6rIZfQC YWtqXRLsVOtWSI1LLlPZqN57H3t37ZeqYCgrjP6w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726644AbfANLs6 (ORCPT ); Mon, 14 Jan 2019 06:48:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:55192 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726534AbfANLs5 (ORCPT ); Mon, 14 Jan 2019 06:48:57 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0B748ADD6; Mon, 14 Jan 2019 11:48:55 +0000 (UTC) Date: Mon, 14 Jan 2019 12:48:53 +0100 From: Michal Hocko To: Michael Ellerman Cc: linux-mm@kvack.org, Pingfan Liu , Dave Hansen , Peter Zijlstra , x86@kernel.org, Benjamin Herrenschmidt , Tony Luck , linuxppc-dev@lists.ozlabs.org, linux-ia64@vger.kernel.org, LKML Subject: Re: [RFC PATCH] x86, numa: always initialize all possible nodes Message-ID: <20190114114853.GE21345@dhcp22.suse.cz> References: <20190114082416.30939-1-mhocko@kernel.org> <87pnszzg9s.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87pnszzg9s.fsf@concordia.ellerman.id.au> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 14-01-19 21:26:39, Michael Ellerman wrote: > Michal Hocko writes: > > > From: Michal Hocko > > > > Pingfan Liu has reported the following splat > > [ 5.772742] BUG: unable to handle kernel paging request at 0000000000002088 > > [ 5.773618] PGD 0 P4D 0 > > [ 5.773618] Oops: 0000 [#1] SMP NOPTI > > [ 5.773618] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc1+ #3 > > [ 5.773618] Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS 1.4.3 06/29/2018 > > [ 5.773618] RIP: 0010:__alloc_pages_nodemask+0xe2/0x2a0 > > [ 5.773618] Code: 00 00 44 89 ea 80 ca 80 41 83 f8 01 44 0f 44 ea 89 da c1 ea 08 83 e2 01 88 54 24 20 48 8b 54 24 08 48 85 d2 0f 85 46 01 00 00 <3b> 77 08 0f 82 3d 01 00 00 48 89 f8 44 89 ea 48 89 > > e1 44 89 e6 89 > > [ 5.773618] RSP: 0018:ffffaa600005fb20 EFLAGS: 00010246 > > [ 5.773618] RAX: 0000000000000000 RBX: 00000000006012c0 RCX: 0000000000000000 > > [ 5.773618] RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000002080 > > [ 5.773618] RBP: 00000000006012c0 R08: 0000000000000000 R09: 0000000000000002 > > [ 5.773618] R10: 00000000006080c0 R11: 0000000000000002 R12: 0000000000000000 > > [ 5.773618] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000002 > > [ 5.773618] FS: 0000000000000000(0000) GS:ffff8c69afe00000(0000) knlGS:0000000000000000 > > [ 5.773618] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 5.773618] CR2: 0000000000002088 CR3: 000000087e00a000 CR4: 00000000003406e0 > > [ 5.773618] Call Trace: > > [ 5.773618] new_slab+0xa9/0x570 > > [ 5.773618] ___slab_alloc+0x375/0x540 > > [ 5.773618] ? pinctrl_bind_pins+0x2b/0x2a0 > > [ 5.773618] __slab_alloc+0x1c/0x38 > > [ 5.773618] __kmalloc_node_track_caller+0xc8/0x270 > > [ 5.773618] ? pinctrl_bind_pins+0x2b/0x2a0 > > [ 5.773618] devm_kmalloc+0x28/0x60 > > [ 5.773618] pinctrl_bind_pins+0x2b/0x2a0 > > [ 5.773618] really_probe+0x73/0x420 > > [ 5.773618] driver_probe_device+0x115/0x130 > > [ 5.773618] __driver_attach+0x103/0x110 > > [ 5.773618] ? driver_probe_device+0x130/0x130 > > [ 5.773618] bus_for_each_dev+0x67/0xc0 > > [ 5.773618] ? klist_add_tail+0x3b/0x70 > > [ 5.773618] bus_add_driver+0x41/0x260 > > [ 5.773618] ? pcie_port_setup+0x4d/0x4d > > [ 5.773618] driver_register+0x5b/0xe0 > > [ 5.773618] ? pcie_port_setup+0x4d/0x4d > > [ 5.773618] do_one_initcall+0x4e/0x1d4 > > [ 5.773618] ? init_setup+0x25/0x28 > > [ 5.773618] kernel_init_freeable+0x1c1/0x26e > > [ 5.773618] ? loglevel+0x5b/0x5b > > [ 5.773618] ? rest_init+0xb0/0xb0 > > [ 5.773618] kernel_init+0xa/0x110 > > [ 5.773618] ret_from_fork+0x22/0x40 > > [ 5.773618] Modules linked in: > > [ 5.773618] CR2: 0000000000002088 > > [ 5.773618] ---[ end trace 1030c9120a03d081 ]--- > > > > with his AMD machine with the following topology > > NUMA node0 CPU(s): 0,8,16,24 > > NUMA node1 CPU(s): 2,10,18,26 > > NUMA node2 CPU(s): 4,12,20,28 > > NUMA node3 CPU(s): 6,14,22,30 > > NUMA node4 CPU(s): 1,9,17,25 > > NUMA node5 CPU(s): 3,11,19,27 > > NUMA node6 CPU(s): 5,13,21,29 > > NUMA node7 CPU(s): 7,15,23,31 > > > > [ 0.007418] Early memory node ranges > > [ 0.007419] node 1: [mem 0x0000000000001000-0x000000000008efff] > > [ 0.007420] node 1: [mem 0x0000000000090000-0x000000000009ffff] > > [ 0.007422] node 1: [mem 0x0000000000100000-0x000000005c3d6fff] > > [ 0.007422] node 1: [mem 0x00000000643df000-0x0000000068ff7fff] > > [ 0.007423] node 1: [mem 0x000000006c528000-0x000000006fffffff] > > [ 0.007424] node 1: [mem 0x0000000100000000-0x000000047fffffff] > > [ 0.007425] node 5: [mem 0x0000000480000000-0x000000087effffff] > > > > and nr_cpus set to 4. The underlying reason is tha the device is bound > > to node 2 which doesn't have any memory and init_cpu_to_node only > > initializes memory-less nodes for possible cpus which nr_cpus restrics. > > This in turn means that proper zonelists are not allocated and the page > > allocator blows up. > > > > Fix the issue by reworking how x86 initializes the memory less nodes. > > The current implementation is hacked into the workflow and it doesn't > > allow any flexibility. There is init_memory_less_node called for each > > offline node that has a CPU as already mentioned above. This will make > > sure that we will have a new online node without any memory. Much later > > on we build a zone list for this node and things seem to work, except > > they do not (e.g. due to nr_cpus). Not to mention that it doesn't really > > make much sense to consider an empty node as online because we just > > consider this node whenever we want to iterate nodes to use and empty > > node is obviously not the best candidate. This is all just too fragile. > > > > Reported-by: Pingfan Liu > > Tested-by: Pingfan Liu > > Signed-off-by: Michal Hocko > > --- > > > > Hi, > > I am sending this as an RFC because I am not sure this is the proper way > > to go myself. I am especially not sure about other architectures > > supporting memoryless nodes (ppc and ia64 AFAICS or are there more?). > > > > I would appreciate a help with those architectures because I couldn't > > really grasp how the memoryless nodes are really initialized there. E.g. > > ppc only seem to call setup_node_data for online nodes but I couldn't > > find any special treatment for nodes without any memory. > > We have a somewhat dubious hack in our hotplug code, see: > > e67e02a544e9 ("powerpc/pseries: Fix cpu hotplug crash with memoryless nodes") > > Which basically onlines the node when we hotplug a CPU into it. Hmm, interesting. So what happens if somebody tries to allocate a memory from a node when it is not online yet? E.g. something like the above. And do I get it right that this patch will not break the current ppc code? -- Michal Hocko SUSE Labs