selftests/vm: use a common gup_test.h

Avoid the need to copy-paste the gup_test ioctl commands and the struct
gup_test definition, between the kernel and the user space application, by
providing a new header file for these.  This allows easier and safer
adding of new ioctl calls, as well as reducing the overall line count.

Details: The header file has to be able to compile independently, because
of the arguably unfortunate way that the Makefile is written: the Makefile
tries to build all of its prerequisites, when really it should be only
building the .c files, and leaving the other prerequisites (LOCAL_HDRS) as
pure dependencies.

That Makefile limitation is probably not worth fixing, but it explains why
one of the includes had to be moved into the new header file.

Also: simplify the ioctl struct (struct gup_test), by deleting the unused
__expansion[10] field.  This sort of thing is what you might see in a
stable ABI, but this low-level, kernel-developer-oriented selftests/vm
system is very much not subject to ABI stability.  So "expansion" and
"reserved" fields are unnecessary here.

Link: https://lkml.kernel.org/r/20201026064021.3545418-3-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
John Hubbard 2020-12-14 19:05:08 -08:00 committed by Linus Torvalds
parent 9c84f22926
commit b9dcfdff8b
4 changed files with 26 additions and 37 deletions

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@ -4,22 +4,7 @@
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <linux/debugfs.h>
#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_test)
#define GUP_BENCHMARK _IOWR('g', 2, struct gup_test)
#define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_test)
#define PIN_BENCHMARK _IOWR('g', 4, struct gup_test)
#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_test)
struct gup_test {
__u64 get_delta_usec;
__u64 put_delta_usec;
__u64 addr;
__u64 size;
__u32 nr_pages_per_call;
__u32 flags;
__u64 expansion[10]; /* For future use */
};
#include "gup_test.h"
static void put_back_pages(unsigned int cmd, struct page **pages,
unsigned long nr_pages)

22
mm/gup_test.h Normal file
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@ -0,0 +1,22 @@
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __GUP_TEST_H
#define __GUP_TEST_H
#include <linux/types.h>
#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_test)
#define GUP_BENCHMARK _IOWR('g', 2, struct gup_test)
#define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_test)
#define PIN_BENCHMARK _IOWR('g', 4, struct gup_test)
#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_test)
struct gup_test {
__u64 get_delta_usec;
__u64 put_delta_usec;
__u64 addr;
__u64 size;
__u32 nr_pages_per_call;
__u32 flags;
};
#endif /* __GUP_TEST_H */

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@ -134,3 +134,5 @@ endif
$(OUTPUT)/userfaultfd: LDLIBS += -lpthread
$(OUTPUT)/mlock-random-test: LDLIBS += -lcap
$(OUTPUT)/gup_test: ../../../../mm/gup_test.h

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@ -2,39 +2,19 @@
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <linux/types.h>
#include "../../../../mm/gup_test.h"
#define MB (1UL << 20)
#define PAGE_SIZE sysconf(_SC_PAGESIZE)
#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_test)
#define GUP_BENCHMARK _IOWR('g', 2, struct gup_test)
/* Similar to above, but use FOLL_PIN instead of FOLL_GET. */
#define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_test)
#define PIN_BENCHMARK _IOWR('g', 4, struct gup_test)
#define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_test)
/* Just the flags we need, copied from mm.h: */
#define FOLL_WRITE 0x01 /* check pte is writable */
struct gup_test {
__u64 get_delta_usec;
__u64 put_delta_usec;
__u64 addr;
__u64 size;
__u32 nr_pages_per_call;
__u32 flags;
__u64 expansion[10]; /* For future use */
};
int main(int argc, char **argv)
{
struct gup_test gup;