Commit bdffe23e authored Jan 30, 2020 by John Hubbard Committed by Linus Torvalds Jan 31, 2020

mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "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 <jhubbard@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent aa4b87fe

mm/gup_benchmark.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -49,18 +49,21 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
		nr = (next - addr) / PAGE_SIZE;
		}

		/* Filter out most gup flags: only allow a tiny subset here: */
		gup->flags &= FOLL_WRITE;

		switch (cmd) {
		case GUP_FAST_BENCHMARK:
		nr = get_user_pages_fast(addr, nr, gup->flags & 1,
		nr = get_user_pages_fast(addr, nr, gup->flags,
		pages + i);
		break;
		case GUP_LONGTERM_BENCHMARK:
		nr = get_user_pages(addr, nr,
		(gup->flags & 1) \| FOLL_LONGTERM,
		gup->flags \| FOLL_LONGTERM,
		pages + i, NULL);
		break;
		case GUP_BENCHMARK:
		nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
		nr = get_user_pages(addr, nr, gup->flags, pages + i,
		NULL);
		break;
		default:

tools/testing/selftests/vm/gup_benchmark.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -18,6 +18,9 @@
		#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
		#define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark)

		/* 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)
		}

		gup.nr_pages_per_call = nr_pages;
		gup.flags = write;
		if (write)
		gup.flags \|= FOLL_WRITE;

		fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR);
		if (fd == -1)