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=-7.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 262C0C4360F for ; Fri, 22 Mar 2019 22:06:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD0C321929 for ; Fri, 22 Mar 2019 22:06:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="ETh0Q+H5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728006AbfCVWGH (ORCPT ); Fri, 22 Mar 2019 18:06:07 -0400 Received: from mail-it1-f194.google.com ([209.85.166.194]:53420 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727440AbfCVWGH (ORCPT ); Fri, 22 Mar 2019 18:06:07 -0400 Received: by mail-it1-f194.google.com with SMTP id w85so5859655itc.3; Fri, 22 Mar 2019 15:06:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=zPnyPNGnsO/md2Fj5yEAI9x91Hz7J9uO8l7Sk2KMvIo=; b=ETh0Q+H5NErnf+anAIeNX89EpJjpuFOFrGA549zU6YNjyodAclghZqMAQhCYHmsdpr VBr/q0cU6fGUQZpceBNwr0M+bLWwnpat9RsFa50fk6EH+Ej3wT3fiVBe0lVTwTugrloo iFU6UFQ36JWbIMUYlh8YNEcsGoj838Wu1icdiWs1qphTBfThMQQSRXpaXXYbY3iRIz+R okhh/FvQVRXB/Q8a7q6XyZrBKwLnS/7Qc7BIuqBvFeFzP4QdI3IylwYJd+W54gfYHbbY V3ldQH0uIH3yxe3qtmId36/CRAoD48vcD7efQl3U/JsBsrDrQh+HlYfRz2uDtxUe2MaL raAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=zPnyPNGnsO/md2Fj5yEAI9x91Hz7J9uO8l7Sk2KMvIo=; b=LotVsiShS9tkqKwG4bbZFbxi8t2a1Ty71UX6agqn9LcC6VIIW1LLMiSFNHQe2Hjf1Y HUUMpgkr0TFzKWFsPMvNtqS//MO/ZLCU9Gcu7gyHBiehmhGpwNg1gzP+AUFkQI3B2ILj ci8vp5WigJj7X1QX7C1Tn/wQHDZdjlfW3YZwjfpwcET09Ech2bJZURzXXjBvMo4qV5RH gRKtfTgZ1ahWLFZ3ql4AnsHDWnxe/CcHpmFOa0l4pAhVTuOkERbAKVyt/Wbpam111Gjq 7r5WonPVlp1TrMqIY+mK0vrnsORsvuua1sEal9EUOSwWGp4E75xfzsfw7sTsYdhBDBvR D4Nw== X-Gm-Message-State: APjAAAUdUxgkLVE4PulqiDmU/mELviTaxf6Xw7/3xyEY97e+AjQ7mZai lRsJue1o3Ng7MTxEIYkmsm2mnzXsgXNvcqzcINA= X-Google-Smtp-Source: APXvYqzvkOUTluGSKTjETBKJlQ9d9U0bafaXjVPDo287WeJSv03XpVRn3tgZfH8AGEVriQsCe7Tjp8XH5gu+GSmr/AQ= X-Received: by 2002:a24:298b:: with SMTP id p133mr3554913itp.43.1553292365179; Fri, 22 Mar 2019 15:06:05 -0700 (PDT) MIME-Version: 1.0 References: <20190317183438.2057-1-ira.weiny@intel.com> <20190317183438.2057-4-ira.weiny@intel.com> In-Reply-To: <20190317183438.2057-4-ira.weiny@intel.com> From: Dan Williams Date: Fri, 22 Mar 2019 15:05:53 -0700 Message-ID: Subject: Re: [RESEND 3/7] mm/gup: Change GUP fast to use flags rather than a write 'bool' To: ira.weiny@intel.com Cc: Andrew Morton , John Hubbard , Michal Hocko , "Kirill A. Shutemov" , Peter Zijlstra , Jason Gunthorpe , Benjamin Herrenschmidt , Paul Mackerras , "David S. Miller" , Martin Schwidefsky , Heiko Carstens , Rich Felker , Yoshinori Sato , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Ralf Baechle , James Hogan , linux-mm , Linux Kernel Mailing List , linux-mips@vger.kernel.org, linuxppc-dev , linux-s390 , Linux-sh , sparclinux@vger.kernel.org, linux-rdma@vger.kernel.org, "netdev@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Mar 17, 2019 at 7:36 PM wrote: > > From: Ira Weiny > > To facilitate additional options to get_user_pages_fast() change the > singular write parameter to be gup_flags. > > This patch does not change any functionality. New functionality will > follow in subsequent patches. > > Some of the get_user_pages_fast() call sites were unchanged because they > already passed FOLL_WRITE or 0 for the write parameter. > > Signed-off-by: Ira Weiny > > --- > Changes from V1: > Rebase to current merge tree > arch/powerpc/mm/mmu_context_iommu.c no longer calls gup_fast > The gup_longterm was converted in patch 1 > > arch/mips/mm/gup.c | 11 ++++++----- > arch/powerpc/kvm/book3s_64_mmu_hv.c | 4 ++-- > arch/powerpc/kvm/e500_mmu.c | 2 +- > arch/s390/kvm/interrupt.c | 2 +- > arch/s390/mm/gup.c | 12 ++++++------ > arch/sh/mm/gup.c | 11 ++++++----- > arch/sparc/mm/gup.c | 9 +++++---- > arch/x86/kvm/paging_tmpl.h | 2 +- > arch/x86/kvm/svm.c | 2 +- > drivers/fpga/dfl-afu-dma-region.c | 2 +- > drivers/gpu/drm/via/via_dmablit.c | 3 ++- > drivers/infiniband/hw/hfi1/user_pages.c | 3 ++- > drivers/misc/genwqe/card_utils.c | 2 +- > drivers/misc/vmw_vmci/vmci_host.c | 2 +- > drivers/misc/vmw_vmci/vmci_queue_pair.c | 6 ++++-- > drivers/platform/goldfish/goldfish_pipe.c | 3 ++- > drivers/rapidio/devices/rio_mport_cdev.c | 4 +++- > drivers/sbus/char/oradax.c | 2 +- > drivers/scsi/st.c | 3 ++- > drivers/staging/gasket/gasket_page_table.c | 4 ++-- > drivers/tee/tee_shm.c | 2 +- > drivers/vfio/vfio_iommu_spapr_tce.c | 3 ++- > drivers/vhost/vhost.c | 2 +- > drivers/video/fbdev/pvr2fb.c | 2 +- > drivers/virt/fsl_hypervisor.c | 2 +- > drivers/xen/gntdev.c | 2 +- > fs/orangefs/orangefs-bufmap.c | 2 +- > include/linux/mm.h | 4 ++-- > kernel/futex.c | 2 +- > lib/iov_iter.c | 7 +++++-- > mm/gup.c | 10 +++++----- > mm/util.c | 8 ++++---- > net/ceph/pagevec.c | 2 +- > net/rds/info.c | 2 +- > net/rds/rdma.c | 3 ++- > 35 files changed, 79 insertions(+), 63 deletions(-) > > diff --git a/arch/mips/mm/gup.c b/arch/mips/mm/gup.c > index 0d14e0d8eacf..4c2b4483683c 100644 > --- a/arch/mips/mm/gup.c > +++ b/arch/mips/mm/gup.c > @@ -235,7 +235,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, > * get_user_pages_fast() - pin user pages in memory > * @start: starting user address > * @nr_pages: number of pages from start to pin > - * @write: whether pages will be written to > + * @gup_flags: flags modifying pin behaviour > * @pages: array that receives pointers to the pages pinned. > * Should be at least nr_pages long. > * > @@ -247,8 +247,8 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, > * requested. If nr_pages is 0 or negative, returns 0. If no pages > * were pinned, returns -errno. > */ > -int get_user_pages_fast(unsigned long start, int nr_pages, int write, > - struct page **pages) > +int get_user_pages_fast(unsigned long start, int nr_pages, > + unsigned int gup_flags, struct page **pages) This looks a tad scary given all related thrash especially when it's only 1 user that wants to do get_user_page_fast_longterm, right? Maybe something like the following. Note I explicitly moved the flags to the end so that someone half paying attention that calls __get_user_pages_fast will get a compile error if they specify the args in the same order. diff --git a/include/linux/mm.h b/include/linux/mm.h index 76ba638ceda8..c6c743bc2c68 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1505,8 +1505,15 @@ static inline long get_user_pages_longterm(unsigned long start, } #endif /* CONFIG_FS_DAX */ -int get_user_pages_fast(unsigned long start, int nr_pages, int write, - struct page **pages); + +int __get_user_pages_fast(unsigned long start, int nr_pages, + struct page **pages, unsigned int gup_flags); + +static inline int get_user_pages_fast(unsigned long start, int nr_pages, int write, + struct page **pages) +{ + return __get_user_pages_fast(start, nr_pages, pages, write ? FOLL_WRITE); +} /* Container for pinned pfns / pages */ struct frame_vector {