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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 42738C282DD for ; Fri, 10 Jan 2020 14:48:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 076392082E for ; Fri, 10 Jan 2020 14:48:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="AYaJEd1o" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 076392082E 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 9346C8E0007; Fri, 10 Jan 2020 09:48:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8E4218E0001; Fri, 10 Jan 2020 09:48:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7FA478E0007; Fri, 10 Jan 2020 09:48:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0224.hostedemail.com [216.40.44.224]) by kanga.kvack.org (Postfix) with ESMTP id 686F48E0001 for ; Fri, 10 Jan 2020 09:48:49 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 20A2782499A8 for ; Fri, 10 Jan 2020 14:48:49 +0000 (UTC) X-FDA: 76362006378.15.bulb14_69f5aacf2905b X-HE-Tag: bulb14_69f5aacf2905b X-Filterd-Recvd-Size: 8448 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Fri, 10 Jan 2020 14:48:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578667727; 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=0754l4wH5GpH8+J8tmqv449PcEO7/r8v1M0+jsB/sr4=; b=AYaJEd1omk4xcDMxC+3pgvyHEND52W3wiHFhN2AI7kf+QeMU9r3+EJjfyoVxnrM6Rrp6+U 4yQV2GSy2uUOX1krXnbpH8pXm7j2YT00zY32OKktoOx/AqDzQEzIujqx9E5aG2OYT2RGHo 3xIur7HB9qJR44ovak88VOkWO8jhmY0= 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-98-lHHsAGbZNs6Du-T4uK9rMA-1; Fri, 10 Jan 2020 09:48:44 -0500 X-MC-Unique: lHHsAGbZNs6Du-T4uK9rMA-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 BAD26CF989; Fri, 10 Jan 2020 14:48:42 +0000 (UTC) Received: from [10.36.118.66] (unknown [10.36.118.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id A248F1001938; Fri, 10 Jan 2020 14:48:40 +0000 (UTC) Subject: Re: [PATCH] mm/page_alloc: Skip non present sections on zone initialization To: "Kirill A. Shutemov" Cc: Michal Hocko , Andrew Morton , Dan Williams , Vlastimil Babka , Mel Gorman , "Jin, Zhi" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" References: <20191230093828.24613-1-kirill.shutemov@linux.intel.com> <20200108144044.GB30379@dhcp22.suse.cz> <73437651-822f-fcec-3b96-281fb1064cf8@redhat.com> <20200110134547.v6ju5dxazknfjdj3@box> <20200110144717.xufpf4yjkjlngymy@box> 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: <6cf49e65-ee02-7cbd-596f-ebbc057717c2@redhat.com> Date: Fri, 10 Jan 2020 15:48:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <20200110144717.xufpf4yjkjlngymy@box> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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 10.01.20 15:47, Kirill A. Shutemov wrote: > On Fri, Jan 10, 2020 at 03:34:49PM +0100, David Hildenbrand wrote: >> On 10.01.20 14:45, Kirill A. Shutemov wrote: >>> On Fri, Jan 10, 2020 at 02:15:26PM +0100, David Hildenbrand wrote: >>>> On 08.01.20 15:40, Michal Hocko wrote: >>>>> On Mon 30-12-19 12:38:28, Kirill A. Shutemov wrote: >>>>>> memmap_init_zone() can be called on the ranges with holes during the >>>>>> boot. It will skip any non-valid PFNs one-by-one. It works fine as long >>>>>> as holes are not too big. >>>>>> >>>>>> But huge holes in the memory map causes a problem. It takes over 20 >>>>>> seconds to walk 32TiB hole. x86-64 with 5-level paging allows for much >>>>>> larger holes in the memory map which would practically hang the system. >>>>>> >>>>>> Deferred struct page init doesn't help here. It only works on the >>>>>> present ranges. >>>>>> >>>>>> Skipping non-present sections would fix the issue. >>>>> >>>>> Makes sense to me. >>>>> >>>>>> Signed-off-by: Kirill A. Shutemov >>>>> >>>>> That pfn inc back and forth is quite ugly TBH but whatever. >>>> >>>> Indeed, can we please rewrite the loop to fix that? >>> >>> Any suggestions? >>> >>> I don't see an obvious way to not break readablity in another place. >>> >> >> I'd probably do it like this (applied some other tweaks, untested) >> >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index cb766aac6772..a96b1ad1d74b 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -5859,6 +5859,22 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn) >> return false; >> } >> >> +static inline __meminit unsigned long next_present_pfn(unsigned long pfn) >> +{ >> +#ifdef CONFIG_SPARSEMEM > > I would rather keep it around function, but it's matter of taste. Yes > >> + unsigned long section_nr = pfn_to_section_nr(pfn + 1); >> + >> + /* >> + * Note: We don't check the subsection bitmap, so this can produce >> + * false positives when only subsections are present/valid. The >> + * caller should recheck if the returned pfn is valid. >> + */ >> + if (!present_section_nr(section_nr)) >> + return section_nr_to_pfn(next_present_section_nr(section_nr)); > > This won't compile. next_present_section_nr() is static to mm/sparse.c. We should then move that to the header IMHO. -- Thanks, David / dhildenb