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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 00693C432C0 for ; Mon, 2 Dec 2019 09:10:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 996C7215E5 for ; Mon, 2 Dec 2019 09:10:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JctgQWMo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 996C7215E5 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 4C0046B0006; Mon, 2 Dec 2019 04:10:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 49A7A6B0007; Mon, 2 Dec 2019 04:10:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 388366B0008; Mon, 2 Dec 2019 04:10:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 245AB6B0006 for ; Mon, 2 Dec 2019 04:10:19 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id B009C180AD80F for ; Mon, 2 Dec 2019 09:10:18 +0000 (UTC) X-FDA: 76219630116.16.toad94_76ead90ba140c X-HE-Tag: toad94_76ead90ba140c X-Filterd-Recvd-Size: 12045 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Mon, 2 Dec 2019 09:10:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575277816; 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=bPkUsTzhkVfJSR03ILlrl/kodSdI4Qx6sX5AFEiswM0=; b=JctgQWMolp2c5Vj5zTU6ql2SQjPr5OO4dhkDZO3BywpOZxg70Op1Bb4CzGT23rqBTkoa3N /iaZjpXcbZFo0TINmk6EDITfHTGT+hWwwTYFviNE036RVzN3EcBDYgB0uEemqJ3WhTp4d1 awXkAfjwTyxO8H5IMM8Lgy+cenb2Ytw= 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-174-gDO2WDkPO7OKY0q6fsiHtA-1; Mon, 02 Dec 2019 04:10:11 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8AD1D1005516; Mon, 2 Dec 2019 09:10:05 +0000 (UTC) Received: from [10.36.117.49] (ovpn-117-49.ams2.redhat.com [10.36.117.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4384A60C05; Mon, 2 Dec 2019 09:09:52 +0000 (UTC) Subject: Re: [PATCH v6 00/10] mm/memory_hotplug: Shrink zones before removing memory To: linux-kernel@vger.kernel.org, Michal Hocko , Oscar Salvador Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, x86@kernel.org, "Aneesh Kumar K . V" , Andrew Morton , Dan Williams , Alexander Duyck , Alexander Potapenko , Andy Lutomirski , Anshuman Khandual , Benjamin Herrenschmidt , Borislav Petkov , Catalin Marinas , Christian Borntraeger , Christophe Leroy , Dave Hansen , Fenghua Yu , Gerald Schaefer , Greg Kroah-Hartman , Halil Pasic , Heiko Carstens , "H. Peter Anvin" , Ingo Molnar , Ira Weiny , Jason Gunthorpe , Jun Yao , Logan Gunthorpe , Mark Rutland , Masahiro Yamada , "Matthew Wilcox (Oracle)" , Mel Gorman , Michael Ellerman , Mike Rapoport , Pankaj Gupta , Paul Mackerras , Pavel Tatashin , Pavel Tatashin , Peter Zijlstra , Qian Cai , Rich Felker , Robin Murphy , Steve Capper , Thomas Gleixner , Tom Lendacky , Tony Luck , Vasily Gorbik , Vlastimil Babka , Wei Yang , Wei Yang , Will Deacon , Yoshinori Sato , Yu Zhao References: <20191006085646.5768-1-david@redhat.com> 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: Date: Mon, 2 Dec 2019 10:09:51 +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: <20191006085646.5768-1-david@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: gDO2WDkPO7OKY0q6fsiHtA-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 06.10.19 10:56, David Hildenbrand wrote: > This series fixes the access of uninitialized memmaps when shrinking > zones/nodes and when removing memory. Also, it contains all fixes for > crashes that can be triggered when removing certain namespace using > memunmap_pages() - ZONE_DEVICE, reported by Aneesh. > > We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be > more involved (we don't have SECTION_IS_ONLINE as an indicator), and > shrinking is only of limited use (set_zone_contiguous() cannot detect > the ZONE_DEVICE as contiguous). > > We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount of > code to a minimum. Shrinking is especially necessary to keep > zone->contiguous set where possible, especially, on memory unplug of > DIMMs at zone boundaries. > > -------------------------------------------------------------------------- > > Zones are now properly shrunk when offlining memory blocks or when > onlining failed. This allows to properly shrink zones on memory unplug > even if the separate memory blocks of a DIMM were onlined to different > zones or re-onlined to a different zone after offlining. > > Example: > > :/# cat /proc/zoneinfo > Node 1, zone Movable > spanned 0 > present 0 > managed 0 > :/# echo "online_movable" > /sys/devices/system/memory/memory41/state > :/# echo "online_movable" > /sys/devices/system/memory/memory43/state > :/# cat /proc/zoneinfo > Node 1, zone Movable > spanned 98304 > present 65536 > managed 65536 > :/# echo 0 > /sys/devices/system/memory/memory43/online > :/# cat /proc/zoneinfo > Node 1, zone Movable > spanned 32768 > present 32768 > managed 32768 > :/# echo 0 > /sys/devices/system/memory/memory41/online > :/# cat /proc/zoneinfo > Node 1, zone Movable > spanned 0 > present 0 > managed 0 > > -------------------------------------------------------------------------- > > I tested this with DIMMs on x86. I didn't test the ZONE_DEVICE part. > > v4 -> v6: > - "mm/memunmap: Don't access uninitialized memmap in memunmap_pages()" > -- Minimize code changes, rephrase subject and description > - "mm/memory_hotplug: Don't access uninitialized memmaps in shrink_zone_span()" > -- Add ifdef to make it compile without ZONE_DEVICE > > v4 -> v5: > - "mm/memory_hotplug: Don't access uninitialized memmaps in shrink_zone_span()" > -- Add more details why ZONE_DEVICE is special > - Include two patches from Aneesh > -- "mm/memunmap: Use the correct start and end pfn when removing pages > from zone" > -- "mm/memmap_init: Update variable name in memmap_init_zone" > > v3 -> v4: > - Drop "mm/memremap: Get rid of memmap_init_zone_device()" > -- As Alexander noticed, it was messy either way > - Drop "mm/memory_hotplug: Exit early in __remove_pages() on BUGs" > - Drop "mm: Exit early in set_zone_contiguous() if already contiguous" > - Drop "mm/memory_hotplug: Optimize zone shrinking code when checking for > holes" > - Merged "mm/memory_hotplug: Remove pages from a zone before removing > memory" and "mm/memory_hotplug: Remove zone parameter from > __remove_pages()" into "mm/memory_hotplug: Shrink zones when offlining > memory" > - Added "mm/memory_hotplug: Poison memmap in remove_pfn_range_from_zone()" > - Stop shrinking ZONE_DEVICE > - Reshuffle patches, moving all fixes to the front. Add Fixes: tags. > - Change subject/description of various patches > - Minor changes (too many to mention) > > Cc: Aneesh Kumar K.V > Cc: Andrew Morton > Cc: Dan Williams > Cc: Michal Hocko > So, patch #1-#4 are already upstream. The other patches have been in -next for quite a long time, and I (+other RH people) ran excessive tests on them. Especially patch #5 is a BUG fix I want to see upstream rather sooner than later (last know "uninitialized memmap" access). Andrew decided not to send these for 5.5 due to lack of ack/review - which is unfortunate, but the right thing to do. @Michal, @Oscar, can some of you at least have a patch #5 now so we can proceed with that? (the other patches can stay in -next some time longer) -- Thanks, David / dhildenb