From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 044/118] mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "1" Date: Thu, 30 Jan 2020 22:13:32 -0800 Message-ID: <20200131061332.OQK3vA8vG%akpm@linux-foundation.org> References: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail.kernel.org ([198.145.29.99]:33072 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725907AbgAaGNd (ORCPT ); Fri, 31 Jan 2020 01:13:33 -0500 In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, alex.williamson@redhat.com, aneesh.kumar@linux.ibm.com, axboe@kernel.dk, bjorn.topel@intel.com, corbet@lwn.net, dan.j.williams@intel.com, daniel.vetter@ffwll.ch, hch@lst.de, hverkuil-cisco@xs4all.nl, ira.weiny@intel.com, jack@suse.cz, jgg@mellanox.com, jgg@ziepe.ca, jglisse@redhat.com, jhubbard@nvidia.com, kirill@shutemov.name, leonro@mellanox.com, linux-mm@kvack.org, mchehab@kernel.org, mm-commits@vger.kernel.org, rppt@linux.ibm.com, torvalds@linux-foundation.org =46rom: John Hubbard Subject: mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-codi= ng "1" Fix the gup benchmark flags to use the symbolic FOLL_WRITE, instead of a hard-coded "1" value. Also, clean up the filtering of gup flags a little, by just doing it once before issuing any of the get_user_pages*() calls. This makes it harder to overlook, instead of having little "gup_flags & 1" phrases in the function calls. Link: http://lkml.kernel.org/r/20200107224558.2362728-22-jhubbard@nvidia.com Signed-off-by: John Hubbard Reviewed-by: Ira Weiny Cc: Alex Williamson Cc: Aneesh Kumar K.V Cc: Bj=C3=B6rn T=C3=B6pel Cc: Christoph Hellwig Cc: Daniel Vetter Cc: Dan Williams Cc: Hans Verkuil Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: Jens Axboe Cc: Jerome Glisse Cc: Jonathan Corbet Cc: Kirill A. Shutemov Cc: Leon Romanovsky Cc: Mauro Carvalho Chehab Cc: Mike Rapoport Signed-off-by: Andrew Morton --- mm/gup_benchmark.c | 9 ++++++--- tools/testing/selftests/vm/gup_benchmark.c | 6 +++++- 2 files changed, 11 insertions(+), 4 deletions(-) --- a/mm/gup_benchmark.c~mm-gup_benchmark-use-proper-foll_write-flags-inste= ad-of-hard-coding-1 +++ a/mm/gup_benchmark.c @@ -49,18 +49,21 @@ static int __gup_benchmark_ioctl(unsigne nr =3D (next - addr) / PAGE_SIZE; } =20 + /* Filter out most gup flags: only allow a tiny subset here: */ + gup->flags &=3D FOLL_WRITE; + switch (cmd) { case GUP_FAST_BENCHMARK: - nr =3D get_user_pages_fast(addr, nr, gup->flags & 1, + nr =3D get_user_pages_fast(addr, nr, gup->flags, pages + i); break; case GUP_LONGTERM_BENCHMARK: nr =3D get_user_pages(addr, nr, - (gup->flags & 1) | FOLL_LONGTERM, + gup->flags | FOLL_LONGTERM, pages + i, NULL); break; case GUP_BENCHMARK: - nr =3D get_user_pages(addr, nr, gup->flags & 1, pages + i, + nr =3D get_user_pages(addr, nr, gup->flags, pages + i, NULL); break; default: --- a/tools/testing/selftests/vm/gup_benchmark.c~mm-gup_benchmark-use-prope= r-foll_write-flags-instead-of-hard-coding-1 +++ a/tools/testing/selftests/vm/gup_benchmark.c @@ -18,6 +18,9 @@ #define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark) =20 +/* Just the flags we need, copied from mm.h: */ +#define FOLL_WRITE 0x01 /* check pte is writable */ + struct gup_benchmark { __u64 get_delta_usec; __u64 put_delta_usec; @@ -85,7 +88,8 @@ int main(int argc, char **argv) } =20 gup.nr_pages_per_call =3D nr_pages; - gup.flags =3D write; + if (write) + gup.flags |=3D FOLL_WRITE; =20 fd =3D open("/sys/kernel/debug/gup_benchmark", O_RDWR); if (fd =3D=3D -1) _