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authorJohn Hubbard <jhubbard@nvidia.com>2020-01-31 07:13:32 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-31 19:30:38 +0100
commitbdffe23eee672fcaa732198c3661f7c1302c6bfa (patch)
tree8f06cfbf828c60f7bbce2a38d2e187ce581565cc
parentpowerpc: book3s64: convert to pin_user_pages() and put_user_page() (diff)
downloadlinux-bdffe23eee672fcaa732198c3661f7c1302c6bfa.tar.xz
linux-bdffe23eee672fcaa732198c3661f7c1302c6bfa.zip
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>
-rw-r--r--mm/gup_benchmark.c9
-rw-r--r--tools/testing/selftests/vm/gup_benchmark.c6
2 files changed, 11 insertions, 4 deletions
diff --git a/mm/gup_benchmark.c b/mm/gup_benchmark.c
index ad9d5b1c4473..8dba38e79a9f 100644
--- a/mm/gup_benchmark.c
+++ b/mm/gup_benchmark.c
@@ -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:
diff --git a/tools/testing/selftests/vm/gup_benchmark.c b/tools/testing/selftests/vm/gup_benchmark.c
index 485cf06ef013..389327e9b30a 100644
--- a/tools/testing/selftests/vm/gup_benchmark.c
+++ b/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)
+/* 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)