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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 D63C7C7619D for ; Wed, 19 Feb 2020 23:55:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99B91206A5 for ; Wed, 19 Feb 2020 23:55:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="dlfLLoL9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726820AbgBSXzN (ORCPT ); Wed, 19 Feb 2020 18:55:13 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:59341 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726613AbgBSXzN (ORCPT ); Wed, 19 Feb 2020 18:55:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582156512; h=from:from:reply-to:subject:subject: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=xqhYdZb7SrAR8FLlGW4qQPuarUA/m5WIsLVS7bktz2E=; b=dlfLLoL9tDlIJ3/kCeM80+9TK36+o55i+wMrBLAY/4Ir8176wtkYXDQIFpiAVxYSnZQJK6 cC6W8yyk60nOoTQwNatJafYG20YWPbSVcce3Y7v3rCT+CWcldtTiSGcoeUlrhRwqu6Krkm AlwRtnnxlC3WqG0PqwTGNVbEWBMMriM= 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-262-oqZy9s0TOi6SMnTK4Z6hbQ-1; Wed, 19 Feb 2020 18:55:08 -0500 X-MC-Unique: oqZy9s0TOi6SMnTK4Z6hbQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2C9B1800D48; Wed, 19 Feb 2020 23:55:07 +0000 (UTC) Received: from localhost (ovpn-12-32.pek2.redhat.com [10.72.12.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A90DF1001281; Wed, 19 Feb 2020 23:55:03 +0000 (UTC) Date: Thu, 20 Feb 2020 07:55:00 +0800 From: Baoquan He To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, richardw.yang@linux.intel.com, david@redhat.com, osalvador@suse.de, dan.j.williams@intel.com, mhocko@suse.com Subject: Re: [PATCH v2 RESEND] mm/sparsemem: pfn_to_page is not valid yet on SPARSEMEM Message-ID: <20200219235500.GC4937@MiWiFi-R3L-srv> References: <20200219030454.4844-1-bhe@redhat.com> <20200219115042.e8738272455292d3a6a6e498@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200219115042.e8738272455292d3a6a6e498@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/19/20 at 11:50am, Andrew Morton wrote: > On Wed, 19 Feb 2020 11:04:54 +0800 Baoquan He wrote: > > > From: Wei Yang > > > > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page() > > doesn't work before sparse_init_one_section() is called. This leads to a > > crash when hotplug memory: > > > > [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000 > > [ 41.840663] #PF: supervisor write access in kernel mode > > [ 41.841822] #PF: error_code(0x0002) - not-present page > > [ 41.842970] PGD 0 P4D 0 > > [ 41.843538] Oops: 0002 [#1] SMP PTI > > [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343 > > [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > > [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn > > [ 41.847904] RIP: 0010:__memset+0x24/0x30 > > [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 > > [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87 > > [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000 > > [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000 > > [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000 > > [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000 > > [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280 > > [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000 > > [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0 > > [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > [ 41.863628] Call Trace: > > [ 41.863983] sparse_add_section+0x1c9/0x26a > > [ 41.864570] __add_pages+0xbf/0x150 > > [ 41.865057] add_pages+0x12/0x60 > > [ 41.865489] add_memory_resource+0xc8/0x210 > > [ 41.866017] ? wake_up_q+0xa0/0xa0 > > [ 41.866416] __add_memory+0x62/0xb0 > > [ 41.866825] acpi_memory_device_add+0x13f/0x300 > > [ 41.867410] acpi_bus_attach+0xf6/0x200 > > [ 41.867890] acpi_bus_scan+0x43/0x90 > > [ 41.868448] acpi_device_hotplug+0x275/0x3d0 > > [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30 > > [ 41.869473] process_one_work+0x1a7/0x370 > > [ 41.869953] worker_thread+0x30/0x380 > > [ 41.870396] ? flush_rcu_work+0x30/0x30 > > [ 41.870846] kthread+0x112/0x130 > > [ 41.871236] ? kthread_create_on_node+0x60/0x60 > > [ 41.871770] ret_from_fork+0x35/0x40 > > > > We should use memmap as it did. > > > > Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug") > > Signed-off-by: Wei Yang > > Acked-by: David Hildenbrand > > Reviewed-by: Baoquan He > > CC: Dan Williams > > This should have included your signed-off-by, as you were on the patch > delivery path. I have made that change to my copy of the patch - is > that OK? OK, thanks. > > I also added a cc:stable. Do we agree this is appropriate? Agree, this breakage happened since subsection hotplug. > > I added Dan's "On x86 the impact is limited to x86_32 builds, or x86_64 > configurations that override the default setting for > SPARSEMEM_VMEMMAP." to the changelog. Looks good, thanks.