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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 93229CA9ED4 for ; Mon, 4 Nov 2019 17:42:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F4D2214B2 for ; Mon, 4 Nov 2019 17:42:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KqpQJptN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729445AbfKDRmT (ORCPT ); Mon, 4 Nov 2019 12:42:19 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:20341 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729488AbfKDRmM (ORCPT ); Mon, 4 Nov 2019 12:42:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572889331; 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; bh=Jx5P8upI6dI7oz+S3BNibk79bUjpeE+hNekAqjPP73c=; b=KqpQJptNv8+VCoCYgSVg0VArGRw30uivWKEdlAc1WfHpnkSr4S7ggMDNM9ukMYCvkhJlsQ ZaqOsJ64uTmKJ7Wq5bKk9yk9jF6PmgSudCEugow/TiOBO77aETV94QMJ+nqz/fbKTC0Dc4 DlfHSB9DgXEwL3FrHFDqcAjal752VmY= 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-256-XL6FPTikNZSBZoFGdWe7Ow-1; Mon, 04 Nov 2019 12:42:07 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 77158107ACC2; Mon, 4 Nov 2019 17:42:03 +0000 (UTC) Received: from redhat.com (unknown [10.20.6.178]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6427A5D6C8; Mon, 4 Nov 2019 17:41:57 +0000 (UTC) Date: Mon, 4 Nov 2019 12:41:55 -0500 From: Jerome Glisse To: John Hubbard Cc: Andrew Morton , Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , bpf@vger.kernel.org, dri-devel@lists.freedesktop.org, kvm@vger.kernel.org, linux-block@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-media@vger.kernel.org, linux-rdma@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-mm@kvack.org, LKML Subject: Re: [PATCH v2 08/18] mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() Message-ID: <20191104174155.GE5134@redhat.com> References: <20191103211813.213227-1-jhubbard@nvidia.com> <20191103211813.213227-9-jhubbard@nvidia.com> MIME-Version: 1.0 In-Reply-To: <20191103211813.213227-9-jhubbard@nvidia.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: XL6FPTikNZSBZoFGdWe7Ow-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Sun, Nov 03, 2019 at 01:18:03PM -0800, John Hubbard wrote: > Convert process_vm_access to use the new pin_user_pages_remote() > call, which sets FOLL_PIN. Setting FOLL_PIN is now required for > code that requires tracking of pinned pages. >=20 > Also, release the pages via put_user_page*(). >=20 > Also, rename "pages" to "pinned_pages", as this makes for > easier reading of process_vm_rw_single_vec(). >=20 > Reviewed-by: Ira Weiny > Signed-off-by: John Hubbard Reviewed-by: J=E9r=F4me Glisse > --- > mm/process_vm_access.c | 28 +++++++++++++++------------- > 1 file changed, 15 insertions(+), 13 deletions(-) >=20 > diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c > index 357aa7bef6c0..fd20ab675b85 100644 > --- a/mm/process_vm_access.c > +++ b/mm/process_vm_access.c > @@ -42,12 +42,11 @@ static int process_vm_rw_pages(struct page **pages, > =09=09if (copy > len) > =09=09=09copy =3D len; > =20 > -=09=09if (vm_write) { > +=09=09if (vm_write) > =09=09=09copied =3D copy_page_from_iter(page, offset, copy, iter); > -=09=09=09set_page_dirty_lock(page); > -=09=09} else { > +=09=09else > =09=09=09copied =3D copy_page_to_iter(page, offset, copy, iter); > -=09=09} > + > =09=09len -=3D copied; > =09=09if (copied < copy && iov_iter_count(iter)) > =09=09=09return -EFAULT; > @@ -96,7 +95,7 @@ static int process_vm_rw_single_vec(unsigned long addr, > =09=09flags |=3D FOLL_WRITE; > =20 > =09while (!rc && nr_pages && iov_iter_count(iter)) { > -=09=09int pages =3D min(nr_pages, max_pages_per_loop); > +=09=09int pinned_pages =3D min(nr_pages, max_pages_per_loop); > =09=09int locked =3D 1; > =09=09size_t bytes; > =20 > @@ -106,14 +105,15 @@ static int process_vm_rw_single_vec(unsigned long a= ddr, > =09=09 * current/current->mm > =09=09 */ > =09=09down_read(&mm->mmap_sem); > -=09=09pages =3D get_user_pages_remote(task, mm, pa, pages, flags, > -=09=09=09=09=09 process_pages, NULL, &locked); > +=09=09pinned_pages =3D pin_user_pages_remote(task, mm, pa, pinned_pages, > +=09=09=09=09=09=09 flags, process_pages, > +=09=09=09=09=09=09 NULL, &locked); > =09=09if (locked) > =09=09=09up_read(&mm->mmap_sem); > -=09=09if (pages <=3D 0) > +=09=09if (pinned_pages <=3D 0) > =09=09=09return -EFAULT; > =20 > -=09=09bytes =3D pages * PAGE_SIZE - start_offset; > +=09=09bytes =3D pinned_pages * PAGE_SIZE - start_offset; > =09=09if (bytes > len) > =09=09=09bytes =3D len; > =20 > @@ -122,10 +122,12 @@ static int process_vm_rw_single_vec(unsigned long a= ddr, > =09=09=09=09=09 vm_write); > =09=09len -=3D bytes; > =09=09start_offset =3D 0; > -=09=09nr_pages -=3D pages; > -=09=09pa +=3D pages * PAGE_SIZE; > -=09=09while (pages) > -=09=09=09put_page(process_pages[--pages]); > +=09=09nr_pages -=3D pinned_pages; > +=09=09pa +=3D pinned_pages * PAGE_SIZE; > + > +=09=09/* If vm_write is set, the pages need to be made dirty: */ > +=09=09put_user_pages_dirty_lock(process_pages, pinned_pages, > +=09=09=09=09=09 vm_write); > =09} > =20 > =09return rc; > --=20 > 2.23.0 >=20