From patchwork Mon Nov 25 23:10:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11261181 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 65F8D1393 for ; Mon, 25 Nov 2019 23:13:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EDF020748 for ; Mon, 25 Nov 2019 23:13:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="ndO1kyYw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727227AbfKYXKt (ORCPT ); Mon, 25 Nov 2019 18:10:49 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:11207 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727217AbfKYXKs (ORCPT ); Mon, 25 Nov 2019 18:10:48 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate16.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 25 Nov 2019 15:10:41 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 25 Nov 2019 15:10:39 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 25 Nov 2019 15:10:39 -0800 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 25 Nov 2019 23:10:39 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Mon, 25 Nov 2019 23:10:38 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 25 Nov 2019 15:10:37 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v2 00/19] pin_user_pages(): reduced-risk series for Linux 5.5 Date: Mon, 25 Nov 2019 15:10:16 -0800 Message-ID: <20191125231035.1539120-1-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1574723442; bh=+fKR9i8A1AVbpAkGEFz1AM9ETJRVeSf0J2MygF32l5w=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: MIME-Version:X-NVConfidentiality:Content-Type: Content-Transfer-Encoding; b=ndO1kyYw+Aj7PJ1b4CON5Q8+SrIcwXlb45V4tj+JVPm5a7tM/5raJmkf+oA8o+7Gn q+DZKnhL8HDAd4gc+VTmeQE/lO9R3WtF6DClR/Ox8lkKenA2hi3RkIsDbZBRb7/N9I u7vqu7OPX0uJIMsnOGPaXiQsQ3livkjU+Uydd8H70Bkagfvsff/O1UWDvtASk/ZD/5 j3u+3hA9MXsiO5zM+Fvjg+mWEqNbbdrTimvMMM1CyULJLiNKjbxsllY9FZaTQHKnou 7YD0HiYvc6l3EAutS7qMBed3ruw+5cxaPaf8mdXNhpDMt5CU2G9r209+vuG622feZ3 9j/62y8q4ASVw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi, Changes since v1: * Fixed up ppc in response to Jan Kara's review comments (thanks for those!). * Fixed a kbuilt robot-detected build failure: added a stub function for the !CONFIG_MMU case. * Cover letter: now refers to "unpin_user_page()", reflecting the name change in the last patch (instead of put_user_page() ). * Rebased onto today's linux-next: c165016bac27 ("Add linux-next specific files for 20191125") ======================================================================== Here is a set of well-reviewed (expect for one patch), lower-risk items that can go into Linux 5.5. (Update: the powerpc conversion patch has had some initial review now, since v1 was posted.) This is essentially a cut-down v8 of "mm/gup: track dma-pinned pages: FOLL_PIN" [1], and with one of the VFIO patches split into two patches. The idea here is to get this long list of "noise" checked into 5.5, so that the actual, higher-risk "track FOLL_PIN pages" (which is deferred: not part of this series) will be a much shorter patchset to review. For the v4l2-core changes, I've left those here (instead of sending them separately to the -media tree), in order to get the name change done now (put_user_page --> unpin_user_page). However, I've added a Cc stable, as recommended during the last round of reviews. Here are the relevant notes from the original cover letter, edited to match the current situation: This is a prerequisite to tracking dma-pinned pages. That in turn is a prerequisite to solving the larger problem of proper interactions between file-backed pages, and [R]DMA activities, as discussed in [1], [2], [3], and in a remarkable number of email threads since about 2017. :) A new internal gup flag, FOLL_PIN is introduced, and thoroughly documented in the last patch's Documentation/vm/pin_user_pages.rst. I believe that this will provide a good starting point for doing the layout lease work that Ira Weiny has been working on. That's because these new wrapper functions provide a clean, constrained, systematically named set of functionality that, again, is required in order to even know if a page is "dma-pinned". In contrast to earlier approaches, the page tracking can be incrementally applied to the kernel call sites that, until now, have been simply calling get_user_pages() ("gup"). In other words, opt-in by changing from this: get_user_pages() (sets FOLL_GET) put_page() to this: pin_user_pages() (sets FOLL_PIN) unpin_user_page() Because there are interdependencies with FOLL_LONGTERM, a similar conversion as for FOLL_PIN, was applied. The change was from this: get_user_pages(FOLL_LONGTERM) (also sets FOLL_GET) put_page() to this: pin_longterm_pages() (sets FOLL_PIN | FOLL_LONGTERM) unpin_user_page() [1] https://lore.kernel.org/r/20191121071354.456618-1-jhubbard@nvidia.com thanks, John Hubbard NVIDIA Dan Williams (1): mm: Cleanup __put_devmap_managed_page() vs ->page_free() John Hubbard (18): mm/gup: factor out duplicate code from four routines mm/gup: move try_get_compound_head() to top, fix minor issues goldish_pipe: rename local pin_user_pages() routine mm: fix get_user_pages_remote()'s handling of FOLL_LONGTERM vfio: fix FOLL_LONGTERM use, simplify get_user_pages_remote() call mm/gup: introduce pin_user_pages*() and FOLL_PIN goldish_pipe: convert to pin_user_pages() and put_user_page() IB/{core,hw,umem}: set FOLL_PIN via pin_user_pages*(), fix up ODP mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() drm/via: set FOLL_PIN via pin_user_pages_fast() fs/io_uring: set FOLL_PIN via pin_user_pages() net/xdp: set FOLL_PIN via pin_user_pages() media/v4l2-core: set pages dirty upon releasing DMA buffers media/v4l2-core: pin_user_pages (FOLL_PIN) and put_user_page() conversion vfio, mm: pin_user_pages (FOLL_PIN) and put_user_page() conversion powerpc: book3s64: convert to pin_user_pages() and put_user_page() mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "1" mm, tree-wide: rename put_user_page*() to unpin_user_page*() Documentation/core-api/index.rst | 1 + Documentation/core-api/pin_user_pages.rst | 233 ++++++++++++++ arch/powerpc/mm/book3s64/iommu_api.c | 12 +- drivers/gpu/drm/via/via_dmablit.c | 6 +- drivers/infiniband/core/umem.c | 4 +- drivers/infiniband/core/umem_odp.c | 13 +- drivers/infiniband/hw/hfi1/user_pages.c | 4 +- drivers/infiniband/hw/mthca/mthca_memfree.c | 8 +- drivers/infiniband/hw/qib/qib_user_pages.c | 4 +- drivers/infiniband/hw/qib/qib_user_sdma.c | 8 +- drivers/infiniband/hw/usnic/usnic_uiom.c | 4 +- drivers/infiniband/sw/siw/siw_mem.c | 4 +- drivers/media/v4l2-core/videobuf-dma-sg.c | 8 +- drivers/nvdimm/pmem.c | 6 - drivers/platform/goldfish/goldfish_pipe.c | 35 +- drivers/vfio/vfio_iommu_type1.c | 35 +- fs/io_uring.c | 6 +- include/linux/mm.h | 77 +++-- mm/gup.c | 340 +++++++++++++------- mm/gup_benchmark.c | 9 +- mm/memremap.c | 80 ++--- mm/process_vm_access.c | 28 +- net/xdp/xdp_umem.c | 4 +- tools/testing/selftests/vm/gup_benchmark.c | 6 +- 24 files changed, 650 insertions(+), 285 deletions(-) create mode 100644 Documentation/core-api/pin_user_pages.rst