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=-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 E6F5CC10F00 for ; Sat, 7 Mar 2020 20:58:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B59F02073D for ; Sat, 7 Mar 2020 20:58:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583614724; bh=zjJ//aCNs/vtEA6bY7bkmMnuDHhAMPNcMoGqO6sDy18=; h=Date:From:To:Subject:In-Reply-To:List-ID:From; b=cXRbrgLimyGvDw6f2X29JOrlfYJFBHOWjgoY2xvK5emSRkYO6eyoK5oLvmSSPMbVn zUvCgg1QEARI15vMJGpSnAwWaNuuEiS74KUAb8m+rzaqTX+y8jixHoj90i2PIHIaKO vugiPCKFC+Fs8wMFOvgvfbQcrs03shaUnAXxs0kg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726109AbgCGU6o (ORCPT ); Sat, 7 Mar 2020 15:58:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:53460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726098AbgCGU6o (ORCPT ); Sat, 7 Mar 2020 15:58:44 -0500 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 BD99620684; Sat, 7 Mar 2020 20:58:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583614723; bh=zjJ//aCNs/vtEA6bY7bkmMnuDHhAMPNcMoGqO6sDy18=; h=Date:From:To:Subject:In-Reply-To:From; b=QYatskmdK8AygpwrR7Pgq3e2vJG1f0StM1+FE6F0pZwIiKeanrmmfHEl311PyCRaZ 3ccO7hSJ4ajJfOn4mQ8qY3oEp+mERzID3Hilh9J+ZfEcyYtZB8+zl+pbHh84FRT0Vk 2hzH5cMMhuWDemyVK2XEhrrhV/+ZRebIO/5UJYMk= Date: Sat, 07 Mar 2020 12:58:42 -0800 From: Andrew Morton To: bhe@redhat.com, david@redhat.com, mhocko@suse.com, mm-commits@vger.kernel.org, osalvador@suse.de, richardw.yang@linux.intel.com, rppt@linux.ibm.com, stable@vger.kernel.org Subject: + mm-hotplug-fix-hot-remove-failure-in-sparsememvmemmap-case.patch added to -mm tree Message-ID: <20200307205842.m2xK7JlGC%akpm@linux-foundation.org> In-Reply-To: <20200305222751.6d781a3f2802d79510941e4e@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 The patch titled Subject: mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case has been added to the -mm tree. Its filename is mm-hotplug-fix-hot-remove-failure-in-sparsememvmemmap-case.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-hotplug-fix-hot-remove-failure-in-sparsememvmemmap-case.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-hotplug-fix-hot-remove-failure-in-sparsememvmemmap-case.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ 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. 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 Cc: Michal Hocko Cc: 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 = false; 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, _ Patches currently in -mm which might be from bhe@redhat.com are mm-hotplug-fix-hot-remove-failure-in-sparsememvmemmap-case.patch mm-hotplug-only-respect-mem=-parameter-during-boot-stage.patch