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=-6.9 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=unavailable 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 D91B8C2D0CE for ; Tue, 21 Jan 2020 18:03:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8AE2324125 for ; Tue, 21 Jan 2020 18:03:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ADwL1iFj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8AE2324125 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 210A66B0279; Tue, 21 Jan 2020 13:03:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C1956B027A; Tue, 21 Jan 2020 13:03:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 05EEB6B027B; Tue, 21 Jan 2020 13:03:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0176.hostedemail.com [216.40.44.176]) by kanga.kvack.org (Postfix) with ESMTP id DEC246B0279 for ; Tue, 21 Jan 2020 13:03:18 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 96E63181AEF15 for ; Tue, 21 Jan 2020 18:03:18 +0000 (UTC) X-FDA: 76402413276.12.north33_74289f5c02b28 X-HE-Tag: north33_74289f5c02b28 X-Filterd-Recvd-Size: 8584 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Jan 2020 18:03:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579629797; 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=uTtwNHdS2IIpvaTdfYSk+ONIaqPDsbPlM+ndeM14IWo=; b=ADwL1iFjmACyHCP/fYBNkOP63K4am+GIWpxw7peTbHQvVcfgCbcHQp6jsa+w7nt75RkrBz gYE6qpphF9Wd3ye/krU0wsbXtjzpWxEIJTwhVERuvBCU3iwTz2E2fJiGIruHlw1gohf6CK Fzrc2LjLpB0bp8Ede5LLQbwfqXtpOms= 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-37-bCHomBeXPL6CaetSmbt7zw-1; Tue, 21 Jan 2020 13:03:09 -0500 X-MC-Unique: bCHomBeXPL6CaetSmbt7zw-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 8F7AC100551A; Tue, 21 Jan 2020 18:03:07 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.36.118.56]) by smtp.corp.redhat.com (Postfix) with ESMTP id DDA015C290; Tue, 21 Jan 2020 18:03:03 +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 18/24] mm/memory_hotplug: make unregister_memory_block_under_nodes() never fail Date: Tue, 21 Jan 2020 19:01:44 +0100 Message-Id: <20200121180150.37454-19-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 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: commit a31b264c2b415b29660da0bc2ba291a98629ce51 upstream. We really don't want anything during memory hotunplug to fail. We always pass a valid memory block device, that check can go. Avoid allocating memory and eventually failing. As we are always called under lock, we can use a static piece of memory. This avoids having to put the structure onto the stack, having to guess about the stack size of callers. Patch inspired by a patch from Oscar Salvador. In the future, there might be no need to iterate over nodes at all. mem->nid should tell us exactly what to remove. Memory block devices with mixed nodes (added during boot) should properly fenced off and never removed. Link: http://lkml.kernel.org/r/20190527111152.16324-11-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Wei Yang Reviewed-by: Oscar Salvador Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: Alex Deucher Cc: "David S. Miller" Cc: Mark Brown Cc: Chris Wilson Cc: David Hildenbrand Cc: Jonathan Cameron Cc: Andrew Banman Cc: Andy Lutomirski Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arun KS Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Chintan Pandya Cc: Christophe Leroy Cc: Dan Williams Cc: Dave Hansen Cc: Fenghua Yu Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Joonsoo Kim Cc: Jun Yao Cc: "Kirill A. Shutemov" Cc: Logan Gunthorpe Cc: Mark Rutland Cc: Masahiro Yamada Cc: Mathieu Malaterre Cc: Michael Ellerman Cc: Mike Rapoport Cc: "mike.travis@hpe.com" Cc: Nicholas Piggin Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Qian Cai Cc: Rich Felker Cc: Rob Herring Cc: Robin Murphy Cc: Thomas Gleixner Cc: Tony Luck Cc: Vasily Gorbik Cc: Will Deacon Cc: Yoshinori Sato Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: David Hildenbrand --- drivers/base/node.c | 18 +++++------------- include/linux/node.h | 5 ++--- 2 files changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index 1211794d658c..bdff237f4167 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -455,20 +455,14 @@ int register_mem_sect_under_node(struct memory_bloc= k *mem_blk, void *arg) =20 /* * Unregister memory block device under all nodes that it spans. + * Has to be called with mem_sysfs_mutex held (due to unlinked_nodes). */ -int unregister_memory_block_under_nodes(struct memory_block *mem_blk) +void unregister_memory_block_under_nodes(struct memory_block *mem_blk) { - NODEMASK_ALLOC(nodemask_t, unlinked_nodes, GFP_KERNEL); unsigned long pfn, sect_start_pfn, sect_end_pfn; + static nodemask_t unlinked_nodes; =20 - if (!mem_blk) { - NODEMASK_FREE(unlinked_nodes); - return -EFAULT; - } - if (!unlinked_nodes) - return -ENOMEM; - nodes_clear(*unlinked_nodes); - + nodes_clear(unlinked_nodes); sect_start_pfn =3D section_nr_to_pfn(mem_blk->start_section_nr); sect_end_pfn =3D section_nr_to_pfn(mem_blk->end_section_nr); for (pfn =3D sect_start_pfn; pfn <=3D sect_end_pfn; pfn++) { @@ -479,15 +473,13 @@ int unregister_memory_block_under_nodes(struct memo= ry_block *mem_blk) continue; if (!node_online(nid)) continue; - if (node_test_and_set(nid, *unlinked_nodes)) + 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)); } - NODEMASK_FREE(unlinked_nodes); - return 0; } =20 int link_mem_sections(int nid, unsigned long start_pfn, unsigned long en= d_pfn) diff --git a/include/linux/node.h b/include/linux/node.h index 9a6db437f2d1..708939bae9aa 100644 --- a/include/linux/node.h +++ b/include/linux/node.h @@ -72,7 +72,7 @@ extern int register_cpu_under_node(unsigned int cpu, un= signed int nid); extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)= ; extern int register_mem_sect_under_node(struct memory_block *mem_blk, void *arg); -extern int unregister_memory_block_under_nodes(struct memory_block *mem_= blk); +extern void unregister_memory_block_under_nodes(struct memory_block *mem= _blk); =20 #ifdef CONFIG_HUGETLBFS extern void register_hugetlbfs_with_node(node_registration_func_t doregi= ster, @@ -104,9 +104,8 @@ static inline int register_mem_sect_under_node(struct= memory_block *mem_blk, { return 0; } -static inline int unregister_memory_block_under_nodes(struct memory_bloc= k *mem_blk) +static inline void unregister_memory_block_under_nodes(struct memory_blo= ck *mem_blk) { - return 0; } =20 static inline void register_hugetlbfs_with_node(node_registration_func_t= reg, --=20 2.24.1