From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752019AbdJDLyL (ORCPT ); Wed, 4 Oct 2017 07:54:11 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:44467 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751696AbdJDLyI (ORCPT ); Wed, 4 Oct 2017 07:54:08 -0400 X-Google-Smtp-Source: AOwi7QA/EzEjoGCdFPlZRv2pawPTErqLnjkobotY2/nhBbLlQYGkIYXCY4xCjRX0Ze+SjKBjzzTioQ== From: Michal Nazarewicz To: Mike Kravetz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Cc: Marek Szyprowski , "Aneesh Kumar K.V" , Joonsoo Kim , Guy Shattah , Christoph Lameter , Mike Kravetz Subject: Re: [RFC] mmap(MAP_CONTIG) In-Reply-To: <21f1ec96-2822-1189-1c95-79a2bb491571@oracle.com> Organization: http://mina86.com/ References: <21f1ec96-2822-1189-1c95-79a2bb491571@oracle.com> Face: 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 X-Face: -TR8(rDTHy/(xl?SfWd1|3:TTgDIatE^t'vop%*gVg[kn$t{EpK(P"VQ=~T2#ysNmJKN$"yTRLB4YQs$4{[.]Fc1)*O]3+XO^oXM>Q#b^ix,O)Zbn)q[y06$`e3?C)`CwR9y5riE=fv^X@x$y?D:XO6L&x4f-}}I4=VRNwiA^t1-ZrVK^07.Pi/57c_du'& OpenPGP: id=AC1F5F5CD41888F8CC8458582060401250751FF4; url=http://mina86.com/mina86.pub X-Hashcash: 1:20:171004:aneesh.kumar@linux.vnet.ibm.com::LaHNIY1V3ogzUr6f:0000000000000000000000000000000Hkv X-Hashcash: 1:20:171004:m.szyprowski@samsung.com::E/gUMybL1Yx1gVBN:00000000000000000000000000000000000000TnF X-Hashcash: 1:20:171004:linux-mm@kvack.org::Lm/qGCLk69gVr598:00000000000000000000000000000000000000000002/2E X-Hashcash: 1:20:171004:mike.kravetz@oracle.com::zLbmKxlCu19onJX0:000000000000000000000000000000000000001s83 X-Hashcash: 1:20:171004:mike.kravetz@oracle.com::UEBxS9I/HcrtiWEr:000000000000000000000000000000000000002tG0 X-Hashcash: 1:20:171004:iamjoonsoo.kim@lge.com::yVnPKd5JJOvT3ARY:000000000000000000000000000000000000000282U X-Hashcash: 1:20:171004:linux-kernel@vger.kernel.org::TUDfD/kavVX97Mdk:0000000000000000000000000000000002VjS X-Hashcash: 1:20:171004:linux-api@vger.kernel.org::fkClTq2ljJnY0Jwr:00000000000000000000000000000000000047p5 X-Hashcash: 1:20:171004:sguy@mellanox.com::0cvRLRPsYy9VyV3U:00000000000000000000000000000000000000000000FYfs X-Hashcash: 1:20:171004:cl@linux.com::yYfv6RRABsmCWYMN:00000DU+b Date: Wed, 04 Oct 2017 13:54:05 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v94BsXSn020915 On Tue, Oct 03 2017, Mike Kravetz wrote: > At Plumbers this year, Guy Shattah and Christoph Lameter gave a presentation > titled 'User space contiguous memory allocation for DMA' [1]. The slides > point out the performance benefits of devices that can take advantage of > larger physically contiguous areas. Issue I have is that kind of memory needed may depend on a device. Some may require contiguous blocks. Some may support scatter-gather. Some may be behind IO-MMU and not care either way. Furthermore, I feel déjà vu. Wasn’t dmabuf supposed to address this issue? -- Best regards ミハウ “𝓶𝓲𝓷𝓪86” ナザレヴイツ «If at first you don’t succeed, give up skydiving»