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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 987C9C43603 for ; Wed, 4 Dec 2019 14:57:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4D726206DF for ; Wed, 4 Dec 2019 14:57:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MtqA9yTV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D726206DF 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 DE5766B0B20; Wed, 4 Dec 2019 09:57:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D95F56B0B21; Wed, 4 Dec 2019 09:57:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C853D6B0B22; Wed, 4 Dec 2019 09:57:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id B27CC6B0B20 for ; Wed, 4 Dec 2019 09:57:12 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 7019252A7 for ; Wed, 4 Dec 2019 14:57:12 +0000 (UTC) X-FDA: 76227761904.16.ring47_3ed2b31693263 X-HE-Tag: ring47_3ed2b31693263 X-Filterd-Recvd-Size: 9212 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Dec 2019 14:57:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575471430; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=sIVe4Jmb8Oj4OLHEaPn7pLPLkOrzQ1mFBxyZ+OgrwuI=; b=MtqA9yTVNiGowGsXVHp0co+rw2gJyZtFn497UAGQQKxh3sPS6Qt3tfp87AOcN3XlJR5AZd /D0/s4BddKJk1Oq5kSkVi2LFBfLB6vYONU30d38KnhTi7FPNno/OK563HdIhvasPvH4Aui FHbd1DVGX5E7AdjPPWG247YQOdNt2GQ= 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-196-ynFj1op_P7mBY-2IGz3O7Q-1; Wed, 04 Dec 2019 09:57:07 -0500 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 1A4E4101F4E0; Wed, 4 Dec 2019 14:57:04 +0000 (UTC) Received: from [10.36.118.91] (unknown [10.36.118.91]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC9841001B28; Wed, 4 Dec 2019 14:56:58 +0000 (UTC) Subject: Re: [PATCH v15 00/23] Generic page walk and ptdump To: Qian Cai Cc: Steven Price , Andrew Morton , Linux-MM , Mark Rutland , the arch/x86 maintainers , Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-kernel@vger.kernel.org, =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Will Deacon , linux-arm-kernel@lists.infradead.org, "Liang, Kan" References: <20191101140942.51554-1-steven.price@arm.com> <1572896147.5937.116.camel@lca.pw> <7B040741-EC8A-4CC0-964B-4046AE2E617A@lca.pw> <16da6118-ac4d-a165-6202-0731a776ac72@arm.com> <911fac4a-2204-f994-a101-16a60fba12e8@redhat.com> <0FA196FD-3FCD-431A-AA3E-21BF00EA07DC@lca.pw> From: David Hildenbrand Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAj4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+uQINBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABiQIl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <9d5f1689-db82-a6da-d51d-08070aa4bad5@redhat.com> Date: Wed, 4 Dec 2019 15:56:58 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <0FA196FD-3FCD-431A-AA3E-21BF00EA07DC@lca.pw> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: ynFj1op_P7mBY-2IGz3O7Q-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit 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: On 04.12.19 15:54, Qian Cai wrote: > > >> On Dec 3, 2019, at 6:02 AM, David Hildenbrand wrote: >> >> On 06.11.19 16:05, Steven Price wrote: >>> On 06/11/2019 13:31, Qian Cai wrote: >>>> >>>> >>>>> On Nov 4, 2019, at 2:35 PM, Qian Cai wrote: >>>>> >>>>> On Fri, 2019-11-01 at 14:09 +0000, Steven Price wrote: >>> [...] >>>>>> Changes since v14: >>>>>> https://lore.kernel.org/lkml/20191028135910.33253-1-steven.price@arm.com/ >>>>>> * Switch walk_page_range() into two functions, the existing >>>>>> walk_page_range() now still requires VMAs (and treats areas without a >>>>>> VMA as a 'hole'). The new walk_page_range_novma() ignores VMAs and >>>>>> will report the actual page table layout. This fixes the previous >>>>>> breakage of /proc//pagemap >>>>>> * New patch at the end of the series which reduces the 'level' numbers >>>>>> by 1 to simplify the code slightly >>>>>> * Added tags >>>>> >>>>> Does this new version also take care of this boot crash seen with v14? Suppose >>>>> it is now breaking CONFIG_EFI_PGT_DUMP=y? The full config is, >>>>> >>>>> https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config >>>>> >>>> >>>> V15 is indeed DOA here. >>> >>> Thanks for finding this, it looks like EFI causes issues here. The below fixes >>> this for me (booting in QEMU). >>> >>> Andrew: do you want me to send out the entire series again for this fix, or >>> can you squash this into mm-pagewalk-allow-walking-without-vma.patch? >>> >>> Thanks, >>> >>> Steve >>> >>> ---8<--- >>> diff --git a/mm/pagewalk.c b/mm/pagewalk.c >>> index c7529dc4f82b..70dcaa23598f 100644 >>> --- a/mm/pagewalk.c >>> +++ b/mm/pagewalk.c >>> @@ -90,7 +90,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, >>> split_huge_pmd(walk->vma, pmd, addr); >>> if (pmd_trans_unstable(pmd)) >>> goto again; >>> - } else if (pmd_leaf(*pmd)) { >>> + } else if (pmd_leaf(*pmd) || !pmd_present(*pmd)) { >>> continue; >>> } >>> >>> @@ -141,7 +141,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, >>> split_huge_pud(walk->vma, pud, addr); >>> if (pud_none(*pud)) >>> goto again; >>> - } else if (pud_leaf(*pud)) { >>> + } else if (pud_leaf(*pud) || !pud_present(*pud)) { >>> continue; >>> } >>> >>> >> >> Even with this fix, booting for me under QEMU fails. See >> >> https://lore.kernel.org/linux-mm/b7ce62f2-9a48-6e48-6685-003431e521aa@redhat.com/ >> > > Yes, for some reasons, this starts to crash on almost all arches here, so it might be worth > for Andrew to revert those in the meantime while allowing Steven to rework. I agree, this produces too much noise. -- Thanks, David / dhildenb