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 4BBD1C352A3 for ; Tue, 11 Feb 2020 14:44:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0065920708 for ; Tue, 11 Feb 2020 14:44:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DeZrttTz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0065920708 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 A05106B02DF; Tue, 11 Feb 2020 09:44:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9B56D6B02E1; Tue, 11 Feb 2020 09:44:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8A4366B02E2; Tue, 11 Feb 2020 09:44:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0121.hostedemail.com [216.40.44.121]) by kanga.kvack.org (Postfix) with ESMTP id 73D726B02DF for ; Tue, 11 Feb 2020 09:44:22 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0B7CC181AEF00 for ; Tue, 11 Feb 2020 14:44:22 +0000 (UTC) X-FDA: 76478116764.03.fowl50_25ffa73073556 X-HE-Tag: fowl50_25ffa73073556 X-Filterd-Recvd-Size: 9904 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Tue, 11 Feb 2020 14:44:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581432260; 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=GvzkN8vqYFc4OaLRpIuWAah6LI9AskSgWunVMTUbzC0=; b=DeZrttTzXcmv3dxXumiwV57LfYwoBltWSfsAGwM44quDKrsOw6+LAjbd5B2/NYD+RxN9cq kkEiwlzhFnaWQnaD5FbOSoj3/t9wr0wKQe1X4UpyjGN4ENyWEy90O7RwklNj1jYkqsCcO4 XTkd8dN1ZDLLbuyLp6a+cDx0qoq62iY= 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-281-LYeryXiCPSajLsJf-hm37A-1; Tue, 11 Feb 2020 09:44:18 -0500 X-MC-Unique: LYeryXiCPSajLsJf-hm37A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DE130801FA2; Tue, 11 Feb 2020 14:44:16 +0000 (UTC) Received: from [10.36.117.14] (ovpn-117-14.ams2.redhat.com [10.36.117.14]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B08090067; Tue, 11 Feb 2020 14:44:15 +0000 (UTC) Subject: Re: [PATCH 1/7] mm/sparse.c: Introduce new function fill_subsection_map() To: Baoquan He Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, dan.j.williams@intel.com, richardw.yang@linux.intel.com References: <20200209104826.3385-1-bhe@redhat.com> <20200209104826.3385-2-bhe@redhat.com> <0463a54b-12cb-667e-7c86-66cd707cec84@redhat.com> <20200211124648.GF8965@MiWiFi-R3L-srv> 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: <659d16c9-79f7-a1d6-ca05-d6164c9c11a6@redhat.com> Date: Tue, 11 Feb 2020 15:44:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200211124648.GF8965@MiWiFi-R3L-srv> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Content-Transfer-Encoding: quoted-printable 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 11.02.20 13:46, Baoquan He wrote: > On 02/10/20 at 10:49am, David Hildenbrand wrote: >> On 09.02.20 11:48, Baoquan He wrote: >>> Wrap the codes filling subsection map in section_activate() into >>> fill_subsection_map(), this makes section_activate() cleaner and >>> easier to follow. >>> >>> Signed-off-by: Baoquan He >>> --- >>> mm/sparse.c | 45 ++++++++++++++++++++++++++++++++++----------- >>> 1 file changed, 34 insertions(+), 11 deletions(-) >>> >>> diff --git a/mm/sparse.c b/mm/sparse.c >>> index c184b69460b7..9ad741ccbeb6 100644 >>> --- a/mm/sparse.c >>> +++ b/mm/sparse.c >>> @@ -788,24 +788,28 @@ static void section_deactivate(unsigned long pf= n, unsigned long nr_pages, >>> depopulate_section_memmap(pfn, nr_pages, altmap); >>> } >>> =20 >>> -static struct page * __meminit section_activate(int nid, unsigned lo= ng pfn, >>> - unsigned long nr_pages, struct vmem_altmap *altmap) >>> +/** >>> + * fill_subsection_map - fill subsection map of a memory region >>> + * @pfn - start pfn of the memory range >>> + * @nr_pages - number of pfns to add in the region >>> + * >>> + * This clears the related subsection map inside one section, and on= ly >>> + * intended for hotplug. >>> + * >>> + * Return: >>> + * * 0 - On success. >>> + * * -EINVAL - Invalid memory region. >>> + * * -EEXIST - Subsection map has been set. >>> + */ >>> +static int fill_subsection_map(unsigned long pfn, unsigned long nr_p= ages) >>> { >>> - DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) =3D { 0 }; >>> struct mem_section *ms =3D __pfn_to_section(pfn); >>> - struct mem_section_usage *usage =3D NULL; >>> + DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) =3D { 0 }; >>> unsigned long *subsection_map; >>> - struct page *memmap; >>> int rc =3D 0; >>> =20 >>> subsection_mask_set(map, pfn, nr_pages); >>> =20 >>> - if (!ms->usage) { >>> - usage =3D kzalloc(mem_section_usage_size(), GFP_KERNEL); >>> - if (!usage) >>> - return ERR_PTR(-ENOMEM); >>> - ms->usage =3D usage; >>> - } >>> subsection_map =3D &ms->usage->subsection_map[0]; >>> =20 >>> if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) >>> @@ -816,6 +820,25 @@ static struct page * __meminit section_activate(= int nid, unsigned long pfn, >>> bitmap_or(subsection_map, map, subsection_map, >>> SUBSECTIONS_PER_SECTION); >>> =20 >>> + return rc; >>> +} >>> + >>> +static struct page * __meminit section_activate(int nid, unsigned lo= ng pfn, >>> + unsigned long nr_pages, struct vmem_altmap *altmap) >>> +{ >>> + struct mem_section *ms =3D __pfn_to_section(pfn); >>> + struct mem_section_usage *usage =3D NULL; >>> + struct page *memmap; >>> + int rc =3D 0; >>> + >>> + if (!ms->usage) { >>> + usage =3D kzalloc(mem_section_usage_size(), GFP_KERNEL); >>> + if (!usage) >>> + return ERR_PTR(-ENOMEM); >>> + ms->usage =3D usage; >>> + } >>> + >>> + rc =3D fill_subsection_map(pfn, nr_pages); >>> if (rc) { >>> if (usage) >>> ms->usage =3D NULL; >>> >> >> What about having two variants of >> section_activate()/section_deactivate() instead? Then we don't have an= y >> subsection related stuff in !subsection code. >=20 > Thanks for looking into this, David. >=20 > Having two variants of section_activate()/section_deactivate() is also > good. Just not like memmap handling which is very different between cla= ssic > sparse and vmemmap, makes having two variants very attractive, the code > and logic in section_activate()/section_deactivate() is not too much, > and both of them basically can share the most of code, these make the > variants way not so necessary. I personally prefer the current way, wha= t > do you think? I was looking at if (nr_pages < PAGES_PER_SECTION && early_section(ms)) return pfn_to_page(pfn); and thought that it is also specific to sub-section handling. I wonder if we can simply move that into the VMEMMAP variant of populate_section_memmap()? But apart from that I agree that the end result with the current approach is also nice. Can you reshuffle the patches, moving the fixes to the very front so we can backport more easily? --=20 Thanks, David / dhildenb