[PATCH 5/8] selftests/vm: only some gup_test items are really benchmarks

John Hubbard
2020-09-28T06:22:03Z

Therefore, some minor cleanup and improvements are in order:

1. Rename the other items appropriately.

2. Stop reporting timing information on the non-benchmark items. It's
still being recorded and is available, but there's no point in
cluttering up the report with data that no one reasonably needs to
check.

3. Don't do iterations, for non-benchmark items.

4. Print out a shorter, more appropriate report for the non-benchmark
tests.

5. Add the command that was run, to the report. This really helps, as
there are quite a lot of options now.

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
Documentation/core-api/pin_user_pages.rst | 2 +-
mm/gup_test.c | 14 +++----
mm/gup_test.h | 8 ++--
tools/testing/selftests/vm/gup_test.c | 47 +++++++++++++++++++----
4 files changed, 51 insertions(+), 20 deletions(-)

diff --git a/Documentation/core-api/pin_user_pages.rst b/Documentation/core-api/pin_user_pages.rst
index eae972b23224..fcf605be43d0 100644
--- a/Documentation/core-api/pin_user_pages.rst
+++ b/Documentation/core-api/pin_user_pages.rst
@@ -226,7 +226,7 @@ This file::
has the following new calls to exercise the new pin*() wrapper functions:

* PIN_FAST_BENCHMARK (./gup_test -a)
-* PIN_BENCHMARK (./gup_test -b)
+* PIN_BASIC_TEST (./gup_test -b)

You can monitor how many total dma-pinned pages have been acquired and released
since the system was booted, via two new /proc/vmstat entries: ::
diff --git a/mm/gup_test.c b/mm/gup_test.c
index a3c86d0fdff7..a980c4a194f0 100644
--- a/mm/gup_test.c
+++ b/mm/gup_test.c
@@ -13,13 +13,13 @@ static void put_back_pages(unsigned int cmd, struct page **pages,

switch (cmd) {
case GUP_FAST_BENCHMARK:
- case GUP_BENCHMARK:
+ case GUP_BASIC_TEST:
for (i = 0; i < nr_pages; i++)
put_page(pages[i]);
break;

case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK:
+ case PIN_BASIC_TEST:
case PIN_LONGTERM_BENCHMARK:
unpin_user_pages(pages, nr_pages);
break;
@@ -34,7 +34,7 @@ static void verify_dma_pinned(unsigned int cmd, struct page **pages,

switch (cmd) {
case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK:
+ case PIN_BASIC_TEST:
case PIN_LONGTERM_BENCHMARK:
for (i = 0; i < nr_pages; i++) {
page = pages[i];
@@ -87,7 +87,7 @@ static int __gup_test_ioctl(unsigned int cmd,
nr = get_user_pages_fast(addr, nr, gup->flags,
pages + i);
break;
- case GUP_BENCHMARK:
+ case GUP_BASIC_TEST:
nr = get_user_pages(addr, nr, gup->flags, pages + i,
NULL);
break;
@@ -95,7 +95,7 @@ static int __gup_test_ioctl(unsigned int cmd,
nr = pin_user_pages_fast(addr, nr, gup->flags,
pages + i);
break;
- case PIN_BENCHMARK:
+ case PIN_BASIC_TEST:
nr = pin_user_pages(addr, nr, gup->flags, pages + i,
NULL);
break;
@@ -148,10 +148,10 @@ static long gup_test_ioctl(struct file *filep, unsigned int cmd,

switch (cmd) {
case GUP_FAST_BENCHMARK:
- case GUP_BENCHMARK:
case PIN_FAST_BENCHMARK:
- case PIN_BENCHMARK:
case PIN_LONGTERM_BENCHMARK:
+ case GUP_BASIC_TEST:
+ case PIN_BASIC_TEST:
break;
default:
return -EINVAL;
diff --git a/mm/gup_test.h b/mm/gup_test.h
index 931c2f3f477a..921b4caad8ef 100644
--- a/mm/gup_test.h
+++ b/mm/gup_test.h
@@ -5,10 +5,10 @@
#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)
+#define PIN_FAST_BENCHMARK _IOWR('g', 2, struct gup_test)
+#define PIN_LONGTERM_BENCHMARK _IOWR('g', 3, struct gup_test)
+#define GUP_BASIC_TEST _IOWR('g', 4, struct gup_test)
+#define PIN_BASIC_TEST _IOWR('g', 5, struct gup_test)

struct gup_test {
__u64 get_delta_usec;
diff --git a/tools/testing/selftests/vm/gup_test.c b/tools/testing/selftests/vm/gup_test.c
index 4e9f5d0ed0fc..67d57a1cc8b6 100644
--- a/tools/testing/selftests/vm/gup_test.c
+++ b/tools/testing/selftests/vm/gup_test.c
@@ -14,12 +14,30 @@
/* Just the flags we need, copied from mm.h: */
#define FOLL_WRITE 0x01 /* check pte is writable */

+static char *cmd_to_str(unsigned long cmd)
+{
+ switch (cmd) {
+ case GUP_FAST_BENCHMARK:
+ return "GUP_FAST_BENCHMARK";
+ case PIN_FAST_BENCHMARK:
+ return "PIN_FAST_BENCHMARK";
+ case PIN_LONGTERM_BENCHMARK:
+ return "PIN_LONGTERM_BENCHMARK";
+ case GUP_BASIC_TEST:
+ return "GUP_BASIC_TEST";
+ case PIN_BASIC_TEST:
+ return "PIN_BASIC_TEST";
+ }
+ return "Unknown command";
+}
+
int main(int argc, char **argv)
{
struct gup_test gup;
unsigned long size = 128 * MB;
int i, fd, filed, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0;
- int cmd = GUP_FAST_BENCHMARK, flags = MAP_PRIVATE;
+ int cmd = GUP_FAST_BENCHMARK;
+ int flags = MAP_PRIVATE;
char *file = "/dev/zero";
char *p;

@@ -29,7 +47,7 @@ int main(int argc, char **argv)
cmd = PIN_FAST_BENCHMARK;
break;
case 'b':
- cmd = PIN_BENCHMARK;
+ cmd = PIN_BASIC_TEST;
break;
case 'L':
cmd = PIN_LONGTERM_BENCHMARK;
@@ -50,7 +68,7 @@ int main(int argc, char **argv)
thp = 0;
break;
case 'U':
- cmd = GUP_BENCHMARK;
+ cmd = GUP_BASIC_TEST;
break;
case 'u':
cmd = GUP_FAST_BENCHMARK;
@@ -100,16 +118,29 @@ int main(int argc, char **argv)
for (; (unsigned long)p < gup.addr + size; p += PAGE_SIZE)
p[0] = 0;

- for (i = 0; i < repeats; i++) {
+ /* Only report timing information on the *_BENCHMARK commands: */
+ if ((cmd == PIN_FAST_BENCHMARK) || (cmd == GUP_FAST_BENCHMARK) ||
+ (cmd == PIN_LONGTERM_BENCHMARK)) {
+ for (i = 0; i < repeats; i++) {
+ gup.size = size;
+ if (ioctl(fd, cmd, &gup))
+ perror("ioctl"), exit(1);
+
+ printf("%s: Time: get:%lld put:%lld us",
+ cmd_to_str(cmd), gup.get_delta_usec,
+ gup.put_delta_usec);
+ if (gup.size != size)
+ printf(", truncated (size: %lld)", gup.size);
+ printf("\n");
+ }
+ } else {
gup.size = size;
if (ioctl(fd, cmd, &gup))
perror("ioctl"), exit(1);

- printf("Time: get:%lld put:%lld us", gup.get_delta_usec,
- gup.put_delta_usec);
+ printf("%s: done\n", cmd_to_str(cmd));
if (gup.size != size)
- printf(", truncated (size: %lld)", gup.size);
- printf("\n");
+ printf("Truncated (size: %lld)\n", gup.size);
}

return 0;
--
2.28.0