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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 EA108C433DF for ; Mon, 6 Jul 2020 09:04:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B049D206F5 for ; Mon, 6 Jul 2020 09:04:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Olu4Kq8l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B049D206F5 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 1CF1B6B0008; Mon, 6 Jul 2020 05:04:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 17F7C6B000A; Mon, 6 Jul 2020 05:04:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 047996B000C; Mon, 6 Jul 2020 05:04:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id E066A6B0008 for ; Mon, 6 Jul 2020 05:04:11 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 652F5181AC9CC for ; Mon, 6 Jul 2020 09:04:11 +0000 (UTC) X-FDA: 77007064302.08.north79_060a87e26eaa Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin08.hostedemail.com (Postfix) with ESMTP id 3E25B1819E785 for ; Mon, 6 Jul 2020 09:04:11 +0000 (UTC) X-HE-Tag: north79_060a87e26eaa X-Filterd-Recvd-Size: 8540 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Mon, 6 Jul 2020 09:04:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594026250; 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=c/UNohWnDyRP26YKnrvwmyHTPQiPda2RaM2s08Zocn8=; b=Olu4Kq8ldyxHpkV+8Nu22gWZZ4KSlIptfnrZ5v5Qf+wC6iq0LaN7SyTsS+SjRUHLjyJSPe 2ZrVLL8rgWyMw1wEWA8e9OzA9bCyYRfQ2PSQJES3kekN0TGV5kZwpnF/+wuesG4D+0fDH+ Uw1yqyRFzNgtQystd0lHutcBaRm20J8= 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-405-cAkoAm6hPrSbSaimbaQd_w-1; Mon, 06 Jul 2020 05:04:06 -0400 X-MC-Unique: cAkoAm6hPrSbSaimbaQd_w-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 603B2107ACCA; Mon, 6 Jul 2020 09:04:02 +0000 (UTC) Received: from [10.36.114.3] (ovpn-114-3.ams2.redhat.com [10.36.114.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id B51AB1001268; Mon, 6 Jul 2020 09:03:49 +0000 (UTC) Subject: Re: [PATCH V4 1/3] mm/sparsemem: Enable vmem_altmap support in vmemmap_populate_basepages() To: Anshuman Khandual , linux-mm@kvack.org Cc: justin.he@arm.com, catalin.marinas@arm.com, akpm@linux-foundation.org, Will Deacon , Mark Rutland , Paul Walmsley , Palmer Dabbelt , Tony Luck , Fenghua Yu , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Mike Rapoport , Michal Hocko , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Dan Williams , Pavel Tatashin , linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org References: <1594004178-8861-1-git-send-email-anshuman.khandual@arm.com> <1594004178-8861-2-git-send-email-anshuman.khandual@arm.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 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: Date: Mon, 6 Jul 2020 11:03:47 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <1594004178-8861-2-git-send-email-anshuman.khandual@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Rspamd-Queue-Id: 3E25B1819E785 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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: > return 0; > @@ -1505,7 +1505,7 @@ int __meminit vmemmap_populate(unsigned long star= t, unsigned long end, int node, > int err; > =20 > if (end - start < PAGES_PER_SECTION * sizeof(struct page)) > - err =3D vmemmap_populate_basepages(start, end, node); > + err =3D vmemmap_populate_basepages(start, end, node, NULL); > else if (boot_cpu_has(X86_FEATURE_PSE)) > err =3D vmemmap_populate_hugepages(start, end, node, altmap); > else if (altmap) { It's somewhat weird that we don't allocate basepages from altmap on x86 (both for sub-sections and without PSE). I wonder if we can simply unlock that with your change. Especially, also handle the !X86_FEATURE_PSE case below properly with an altmap. a) all hw with PMEM has PSE - except special QEMU setups, so nobody cared to implement. For the sub-section special case, nobody cared about a handfull of memmap not ending up on the altmap. (but it's still wasted system memory IIRC). b) the pagetable overhead for small pages is not-neglectable and might result in similar issues as solved by the switch to altmap on very huge PMEM (with small amount of system RAM). I guess it is due to a). [...] > =20 > -pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr,= int node) > +pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr,= int node, > + struct vmem_altmap *altmap) > { > pte_t *pte =3D pte_offset_kernel(pmd, addr); > if (pte_none(*pte)) { > pte_t entry; > - void *p =3D vmemmap_alloc_block_buf(PAGE_SIZE, node); > + void *p; > + > + if (altmap) > + p =3D altmap_alloc_block_buf(PAGE_SIZE, altmap); > + else > + p =3D vmemmap_alloc_block_buf(PAGE_SIZE, node); > if (!p) > return NULL; I was wondering if if (altmap) p =3D altmap_alloc_block_buf(PAGE_SIZE, altmap); if (!p) p =3D vmemmap_alloc_block_buf(PAGE_SIZE, node); if (!p) return NULL Would make sense. But I guess this isn't really relevant in practice, because the altmap is usually sized properly. In general, LGTM. --=20 Thanks, David / dhildenb