From patchwork Tue Jan 21 18:01:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 233627 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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS 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 0B9C1C33CAA for ; Tue, 21 Jan 2020 18:03:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C92E724125 for ; Tue, 21 Jan 2020 18:03:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GeokAkpl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729127AbgAUSDe (ORCPT ); Tue, 21 Jan 2020 13:03:34 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:33303 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728901AbgAUSDe (ORCPT ); Tue, 21 Jan 2020 13:03:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579629813; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KTjEjUlMxE+1FeA+9rvGI6ZQpOmYiCnZtwWVJmVE5AQ=; b=GeokAkplraeLNOxKRB6t3XsZxBlsGSd2VZpO+KOrTAObeB/DWax6RF7EqP1v9WZhhiK0Vx nNl0FdmEJxqrQFPX9Js/F5kuTQFzcgg0VYuvDHRhcPIkDj+AwzeTE7y73EGYSGI1L4EOCM oIEoSH8Cwnk2qahK3hmz12VviUZgqPw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-260-XFlDHh-eM02tqBhl6FYmTw-1; Tue, 21 Jan 2020 13:03:29 -0500 X-MC-Unique: XFlDHh-eM02tqBhl6FYmTw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B1EED802569; Tue, 21 Jan 2020 18:03:27 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.36.118.56]) by smtp.corp.redhat.com (Postfix) with ESMTP id C26185C545; Tue, 21 Jan 2020 18:03:19 +0000 (UTC) From: David Hildenbrand To: stable@vger.kernel.org Cc: linux-mm@kvack.org, Michal Hocko , Greg Kroah-Hartman , Andrew Morton , "Aneesh Kumar K . V" , Baoquan He , Dan Williams , Oscar Salvador , Wei Yang , David Hildenbrand Subject: [PATCH for 4.19-stable v2 21/24] drivers/base/node.c: simplify unregister_memory_block_under_nodes() Date: Tue, 21 Jan 2020 19:01:47 +0100 Message-Id: <20200121180150.37454-22-david@redhat.com> In-Reply-To: <20200121180150.37454-1-david@redhat.com> References: <20200121180150.37454-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit d84f2f5a755208da3f93e17714631485cb3da11c upstream. We don't allow to offline memory block devices that belong to multiple numa nodes. Therefore, such devices can never get removed. It is sufficient to process a single node when removing the memory block. No need to iterate over each and every PFN. We already have the nid stored for each memory block. Make sure that the nid always has a sane value. Please note that checking for node_online(nid) is not required. If we would have a memory block belonging to a node that is no longer offline, then we would have a BUG in the node offlining code. Link: http://lkml.kernel.org/r/20190719135244.15242-1-david@redhat.com Signed-off-by: David Hildenbrand Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: David Hildenbrand Cc: Stephen Rothwell Cc: Pavel Tatashin Cc: Michal Hocko Cc: Oscar Salvador Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: David Hildenbrand --- drivers/base/memory.c | 1 + drivers/base/node.c | 39 +++++++++++++++------------------------ 2 files changed, 16 insertions(+), 24 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index fdda7a6d712e..fde8d34a1c16 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -693,6 +693,7 @@ static int init_memory_block(struct memory_block **memory, int block_id, mem->state = state; start_pfn = section_nr_to_pfn(mem->start_section_nr); mem->phys_device = arch_get_memory_phys_device(start_pfn); + mem->nid = NUMA_NO_NODE; ret = register_memory(mem); diff --git a/drivers/base/node.c b/drivers/base/node.c index bdff237f4167..f3565c2dbc52 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -409,8 +409,6 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) int ret, nid = *(int *)arg; unsigned long pfn, sect_start_pfn, sect_end_pfn; - mem_blk->nid = nid; - sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); sect_end_pfn += PAGES_PER_SECTION - 1; @@ -439,6 +437,13 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) if (page_nid != nid) continue; } + + /* + * If this memory block spans multiple nodes, we only indicate + * the last processed node. + */ + mem_blk->nid = nid; + ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj, &mem_blk->dev.kobj, kobject_name(&mem_blk->dev.kobj)); @@ -454,32 +459,18 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg) } /* - * Unregister memory block device under all nodes that it spans. - * Has to be called with mem_sysfs_mutex held (due to unlinked_nodes). + * Unregister a memory block device under the node it spans. Memory blocks + * with multiple nodes cannot be offlined and therefore also never be removed. */ void unregister_memory_block_under_nodes(struct memory_block *mem_blk) { - unsigned long pfn, sect_start_pfn, sect_end_pfn; - static nodemask_t unlinked_nodes; - - nodes_clear(unlinked_nodes); - sect_start_pfn = section_nr_to_pfn(mem_blk->start_section_nr); - sect_end_pfn = section_nr_to_pfn(mem_blk->end_section_nr); - for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) { - int nid; + if (mem_blk->nid == NUMA_NO_NODE) + return; - nid = get_nid_for_pfn(pfn); - if (nid < 0) - continue; - if (!node_online(nid)) - continue; - if (node_test_and_set(nid, unlinked_nodes)) - continue; - sysfs_remove_link(&node_devices[nid]->dev.kobj, - kobject_name(&mem_blk->dev.kobj)); - sysfs_remove_link(&mem_blk->dev.kobj, - kobject_name(&node_devices[nid]->dev.kobj)); - } + sysfs_remove_link(&node_devices[mem_blk->nid]->dev.kobj, + kobject_name(&mem_blk->dev.kobj)); + sysfs_remove_link(&mem_blk->dev.kobj, + kobject_name(&node_devices[mem_blk->nid]->dev.kobj)); } int link_mem_sections(int nid, unsigned long start_pfn, unsigned long end_pfn)