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=-6.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 B4C5FC433E6 for ; Sun, 10 Jan 2021 15:40:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 853F22343F for ; Sun, 10 Jan 2021 15:40:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726761AbhAJPky (ORCPT ); Sun, 10 Jan 2021 10:40:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:41438 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726503AbhAJPkx (ORCPT ); Sun, 10 Jan 2021 10:40:53 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 70B6A23358; Sun, 10 Jan 2021 15:40:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610293212; bh=sZZwlJ3yo9cdo2Q1feiwUb2pEDhJYLI0mxxpeUfoZCY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ndleLGPbsnozSM1XAeMwQoc/f5uM0MBaDF+lNILTFOeZwombat42tWmZhvgKxf6n2 tbPBVQ3nRtxEyALKmYz7AGA2uFij+cARr4MqCrbVTVLL8NCS1YjOFVL8UWDU8z5Gc7 KkoTCxCuAlqMRvwA22DoH/dQKY2Ld4g67prHllkFZOasoTkoy/Ed2gjD0GVecUiS7E 8ejavUqPyjt90qe5yWpA8F648bWXfsZGNmtN5gJT/Ez0xjDkh6vNGghkDOJOQx7L73 lfqYws/j6e9rm/31slgpvFko0U6oTUTFu05H90rV3sJJoHY0Ii/seGOGVBTb/9yIp4 0N1Ov9F1nelrA== Date: Sun, 10 Jan 2021 17:39:56 +0200 From: Mike Rapoport To: Qian Cai Cc: Andrew Morton , Andrea Arcangeli , Baoquan He , David Hildenbrand , Mel Gorman , Michal Hocko , Mike Rapoport , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Stephen Rothwell , Linux Next Mailing List Subject: Re: [PATCH v2 2/2] mm: fix initialization of struct page for holes in memory layout Message-ID: <20210110153956.GD1106298@kernel.org> References: <20201209214304.6812-1-rppt@kernel.org> <20201209214304.6812-3-rppt@kernel.org> <768cb57d6ef0989293b3f9fbe0af8e8851723ea1.camel@redhat.com> <20210105082403.GA1106298@kernel.org> <67ef893f27551f80ecf49ef78c0ebc05d3e41b46.camel@redhat.com> <20210106080553.GB1106298@kernel.org> <8171f5a5a8b407a1fcca56bab912555bde80d323.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8171f5a5a8b407a1fcca56bab912555bde80d323.camel@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 06, 2021 at 04:04:21PM -0500, Qian Cai wrote: > On Wed, 2021-01-06 at 10:05 +0200, Mike Rapoport wrote: > > I think we trigger PF_POISONED_CHECK() in PageSlab(), then fffffffffffffffe > > is "accessed" from VM_BUG_ON_PAGE(). > > > > It seems to me that we are not initializing struct pages for holes at the node > > boundaries because zones are already clamped to exclude those holes. > > > > Can you please try to see if the patch below will produce any useful info: > > [ 0.000000] init_unavailable_range: spfn: 8c, epfn: 9b, zone: DMA, node: 0 > [ 0.000000] init_unavailable_range: spfn: 1f7be, epfn: 1f9fe, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 28784, epfn: 288e4, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 298b9, epfn: 298bd, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 29923, epfn: 29931, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 29933, epfn: 29941, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 29945, epfn: 29946, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 29ff9, epfn: 2a823, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 33a23, epfn: 33a53, zone: DMA32, node: 0 > [ 0.000000] init_unavailable_range: spfn: 78000, epfn: 100000, zone: DMA32, node: 0 > ... > [ 572.222563][ T2302] kpagecount_read: pfn 47f380 is poisoned ... > [ 590.570032][ T2302] kpagecount_read: pfn 47ffff is poisoned > [ 604.268653][ T2302] kpagecount_read: pfn 87ff80 is poisoned ... > [ 604.611698][ T2302] kpagecount_read: pfn 87ffbc is poisoned > [ 617.484205][ T2302] kpagecount_read: pfn c7ff80 is poisoned ... > [ 618.212344][ T2302] kpagecount_read: pfn c7ffff is poisoned > [ 633.134228][ T2302] kpagecount_read: pfn 107ff80 is poisoned ... > [ 633.874087][ T2302] kpagecount_read: pfn 107ffff is poisoned > [ 647.686412][ T2302] kpagecount_read: pfn 147ff80 is poisoned ... > [ 648.425548][ T2302] kpagecount_read: pfn 147ffff is poisoned > [ 663.692630][ T2302] kpagecount_read: pfn 187ff80 is poisoned ... > [ 664.432671][ T2302] kpagecount_read: pfn 187ffff is poisoned > [ 675.462757][ T2302] kpagecount_read: pfn 1c7ff80 is poisoned ... > [ 676.202548][ T2302] kpagecount_read: pfn 1c7ffff is poisoned > [ 687.121605][ T2302] kpagecount_read: pfn 207ff80 is poisoned ... > [ 687.860981][ T2302] kpagecount_read: pfn 207ffff is poisoned The e820 map has a hole near the end of each node and these holes are not initialized with init_unavailable_range() after it was interleaved with memmap initialization because such holes are not accounted by zone->spanned_pages. Yet, I'm still cannot really understand how this never triggered VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page); before v5.7 as all the struct pages for these holes would have zone=0 and node=0 ... @Qian, can you please boot your system with memblock=debug and share the logs? -- Sincerely yours, Mike.