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 48CB9C433EF for ; Wed, 8 Dec 2021 08:54:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229925AbhLHI6B (ORCPT ); Wed, 8 Dec 2021 03:58:01 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:46560 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229901AbhLHI55 (ORCPT ); Wed, 8 Dec 2021 03:57:57 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 6759A2190C; Wed, 8 Dec 2021 08:54:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1638953665; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=pm3CQqzDfZysNCdDrMNsbc14dEhsOSwcfRZosLCd9F0=; b=s66lMePlAwCh1//ggKlRXJ7Y6WsGxR6ORREo0/HVMDypZ2gPcCl1esJJo9O7R2OsraHWPF QEGIA0xlXOGCnqdB5dJsG5TvK/AYEjMpYj2OpohLbscyS1BQ8fhpPD7fMQhRaw65N4sqKL wBcc5DgP9Owc6XNulOkYtYwiRGbsGOA= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 3890FA3B81; Wed, 8 Dec 2021 08:54:25 +0000 (UTC) Date: Wed, 8 Dec 2021 09:54:24 +0100 From: Michal Hocko To: Alexey Makhalov Cc: Dennis Zhou , Eric Dumazet , "linux-mm@kvack.org" , Andrew Morton , David Hildenbrand , Oscar Salvador , Tejun Heo , Christoph Lameter , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: Re: [PATCH v3] mm: fix panic in __alloc_pages Message-ID: References: <20211108202325.20304-1-amakhalov@vmware.com> <2e191db3-286f-90c6-bf96-3f89891e9926@gmail.com> <5239D699-523C-4F0C-923A-B068E476043E@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexey, this is still not finalized but it would really help if you could give it a spin on your setup. I still have to think about how to transition from a memoryless node to standard node (in hotplug code). Also there might be other surprises on the way. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c5952749ad40..8ed8db2ccb13 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6382,7 +6382,11 @@ static void __build_all_zonelists(void *data) if (self && !node_online(self->node_id)) { build_zonelists(self); } else { - for_each_online_node(nid) { + /* + * All possible nodes have pgdat preallocated + * free_area_init + */ + for_each_node(nid) { pg_data_t *pgdat = NODE_DATA(nid); build_zonelists(pgdat); @@ -8032,8 +8036,32 @@ void __init free_area_init(unsigned long *max_zone_pfn) /* Initialise every node */ mminit_verify_pageflags_layout(); setup_nr_node_ids(); - for_each_online_node(nid) { - pg_data_t *pgdat = NODE_DATA(nid); + for_each_node(nid) { + pg_data_t *pgdat; + + if (!node_online(nid)) { + pr_warn("Node %d uninitialized by the platform. Please report with boot dmesg.\n", nid); + + /* Allocator not initialized yet */ + pgdat = memblock_alloc(sizeof(*pgdat), SMP_CACHE_BYTES); + if (!pgdat) { + pr_err("Cannot allocate %zuB for node %d.\n", + sizeof(*pgdat), nid); + continue; + } + /* TODO do we need this for memoryless nodes */ + pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); + arch_refresh_nodedata(nid, pgdat); + free_area_init_memoryless_node(nid); + /* + * not marking this node online because we do not want to + * confuse userspace by sysfs files/directories for node + * without any memory attached to it (see topology_init) + */ + continue; + } + + pgdat = NODE_DATA(nid); free_area_init_node(nid); /* Any memory on that node */ -- Michal Hocko SUSE Labs