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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 94E29C10F27 for ; Tue, 10 Mar 2020 18:22:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D98F208C3 for ; Tue, 10 Mar 2020 18:22:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727250AbgCJSWZ (ORCPT ); Tue, 10 Mar 2020 14:22:25 -0400 Received: from shelob.surriel.com ([96.67.55.147]:50150 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726752AbgCJSWZ (ORCPT ); Tue, 10 Mar 2020 14:22:25 -0400 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.3) (envelope-from ) id 1jBjWD-0007pX-Th; Tue, 10 Mar 2020 14:22:17 -0400 Message-ID: <833c188c0c1b9b0b842973952907bdabed774122.camel@surriel.com> Subject: Re: [PATCH v2] mm: hugetlb: optionally allocate gigantic hugepages using cma From: Rik van Riel To: Roman Gushchin , Mike Kravetz Cc: Andrew Morton , Johannes Weiner , Michal Hocko , linux-mm@kvack.org, kernel-team@fb.com, linux-kernel@vger.kernel.org Date: Tue, 10 Mar 2020 14:22:17 -0400 In-Reply-To: <20200310180558.GD85000@carbon.dhcp.thefacebook.com> References: <20200310002524.2291595-1-guro@fb.com> <5cfa9031-fc15-2bcc-adb9-9779285ef0f7@oracle.com> <20200310180558.GD85000@carbon.dhcp.thefacebook.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-D94rFl3rXI1Y1H51/0DC" User-Agent: Evolution 3.34.3 (3.34.3-1.fc31) MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-D94rFl3rXI1Y1H51/0DC Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2020-03-10 at 11:05 -0700, Roman Gushchin wrote: > On Tue, Mar 10, 2020 at 10:27:01AM -0700, Mike Kravetz wrote: > >=20 > > > + for_each_node_state(nid, N_ONLINE) { > > > + unsigned long min_pfn =3D 0, max_pfn =3D 0; > > > + > > > + for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, > > > NULL) { > > > + if (!min_pfn) > > > + min_pfn =3D start_pfn; > > > + max_pfn =3D end_pfn; > > > + } > > > + > > > + res =3D cma_declare_contiguous(PFN_PHYS(min_pfn), size, > > > + PFN_PHYS(max_pfn), (1UL << > > > 30), > >=20 > > The alignment is hard coded for x86 gigantic page size. If this > > supports > > more architectures or becomes arch independent we will need to > > determine > > what this alignment should be. Perhaps an arch specific call back > > to get > > the alignment for gigantic pages. That will require a little > > thought as > > some arch's support multiple gigantic page sizes. >=20 > Good point! > Should we take the biggest possible size as a reference? > Or the smallest (larger than MAX_ORDER)? I would say biggest. You can always allocate multiple smaller gigantic pages inside the space reserved for one ginormous one. --=20 All Rights Reversed. --=-D94rFl3rXI1Y1H51/0DC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAl5n2tkACgkQznnekoTE 3oN+Owf/Sy6WliqWQnAbEHq56M8WlOqyAKoXZupvl2NMopJY6+FsMKMtOezaF0+s 7jli5AA4QEwoCAcLAWsfwZa5lmnrCs918KI8pnQ+6xFFDh7bg9j+iyxvS87SUseM jOiAjAdjHIODLlz5Q7lHktmtO68cU8QDcKjbBtobntk+LS7oGA+FwucdRaZ/hLyI +Rn43qwaod6UxqZCkoNblYlxJhosQfF7bZ99Gkmh+K09lEmgylK0fObIpPIfKI4q sYBTMe7qUzdsfqAOFmF5xzRZX2q0mwOCdTZhjpZ68MjRpHsvKstrlh4UqfAgd7D+ uDn75ec2IPpFAR/8DTp06Kl6a1+q2g== =tGVb -----END PGP SIGNATURE----- --=-D94rFl3rXI1Y1H51/0DC--