From patchwork Sun Mar 22 01:22:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 228914 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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=no 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 285B5C4332D for ; Sun, 22 Mar 2020 01:22:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1FDA20776 for ; Sun, 22 Mar 2020 01:22:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584840136; bh=wxm93Vm+4qrFdWvilJt/Pg/Fhx76X//hnCX8KhDSgDw=; h=Date:From:To:Subject:In-Reply-To:List-ID:From; b=cM610W7zKZ5w7U21kJ8fouJVntSSHs3gY5NwUoi4DQiUsmJ+93LDGKM9PifW9Ip5N Bi5WnlRzkkClggVrNJcqaBJo+rvpQ0NnRPwG8O8nuuzIk0fZUsdnleb6WE26hmPOts 8ylwomRvHizoo51RCp6NKQFV0pHCOk9gQd1Ibmm4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728075AbgCVBWP (ORCPT ); Sat, 21 Mar 2020 21:22:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:41006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726859AbgCVBWP (ORCPT ); Sat, 21 Mar 2020 21:22:15 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1B68C20757; Sun, 22 Mar 2020 01:22:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584840134; bh=wxm93Vm+4qrFdWvilJt/Pg/Fhx76X//hnCX8KhDSgDw=; h=Date:From:To:Subject:In-Reply-To:From; b=AgAD4p4m7Rib0TctHxKmYFN1SWbLGb8Boi9TndmYjtCEeh5+mUSx2qBYP8deUyjCM +8upMLkjOytTf9bEokl5bLtJEYt1IN8HcdSqpDbzADZG5BiFZaRhEzxB8kLacQrGa7 7PYI8L7ZRD9bvGqRRRL/++YtX2nAlT7/Giv+9RM0= Date: Sat, 21 Mar 2020 18:22:13 -0700 From: Andrew Morton To: akpm@linux-foundation.org, bhe@redhat.com, david@redhat.com, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, osalvador@suse.de, pankaj.gupta.linux@gmail.com, richardw.yang@linux.intel.com, rppt@linux.ibm.com, stable@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 02/10] mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case Message-ID: <20200322012213.bAcH5rYaA%akpm@linux-foundation.org> In-Reply-To: <20200321181954.c0564dfd5514cd742b534884@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Baoquan He Subject: mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case In section_deactivate(), pfn_to_page() doesn't work any more after ms->section_mem_map is resetting to NULL in SPARSEMEM|!VMEMMAP case. It caused hot remove failure: kernel BUG at mm/page_alloc.c:4806! invalid opcode: 0000 [#1] SMP PTI CPU: 3 PID: 8 Comm: kworker/u16:0 Tainted: G W 5.5.0-next-20200205+ #340 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: kacpi_hotplug acpi_hotplug_work_fn RIP: 0010:free_pages+0x85/0xa0 Call Trace: __remove_pages+0x99/0xc0 arch_remove_memory+0x23/0x4d try_remove_memory+0xc8/0x130 ? walk_memory_blocks+0x72/0xa0 __remove_memory+0xa/0x11 acpi_memory_device_remove+0x72/0x100 acpi_bus_trim+0x55/0x90 acpi_device_hotplug+0x2eb/0x3d0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x1a7/0x370 worker_thread+0x30/0x380 ? flush_rcu_work+0x30/0x30 kthread+0x112/0x130 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x35/0x40 Let's move the ->section_mem_map resetting after depopulate_section_memmap() to fix it. [akpm@linux-foundation.org: remove unneeded initialization, per David] Link: http://lkml.kernel.org/r/20200307084229.28251-2-bhe@redhat.com Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") Signed-off-by: Baoquan He Acked-by: Michal Hocko Reviewed-by: Pankaj Gupta Reviewed-by: David Hildenbrand Cc: Wei Yang Cc: Oscar Salvador Cc: Mike Rapoport Cc: Signed-off-by: Andrew Morton --- mm/sparse.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/mm/sparse.c~mm-hotplug-fix-hot-remove-failure-in-sparsememvmemmap-case +++ a/mm/sparse.c @@ -734,6 +734,7 @@ static void section_deactivate(unsigned struct mem_section *ms = __pfn_to_section(pfn); bool section_is_early = early_section(ms); struct page *memmap = NULL; + bool empty; unsigned long *subsection_map = ms->usage ? &ms->usage->subsection_map[0] : NULL; @@ -764,7 +765,8 @@ static void section_deactivate(unsigned * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified */ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); - if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { + empty = bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION); + if (empty) { unsigned long section_nr = pfn_to_section_nr(pfn); /* @@ -779,13 +781,15 @@ static void section_deactivate(unsigned ms->usage = NULL; } memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); - ms->section_mem_map = (unsigned long)NULL; } if (section_is_early && memmap) free_map_bootmem(memmap); else depopulate_section_memmap(pfn, nr_pages, altmap); + + if (empty) + ms->section_mem_map = (unsigned long)NULL; } static struct page * __meminit section_activate(int nid, unsigned long pfn,