selftests/vm: only some gup_test items are really benchmarks

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.

6. Use a larger integer type for cmd, now that it's being compared
   Otherwise it doesn't work, because in this case cmd is about 3 billion,
   which is the perfect size for problems with signed vs unsigned int.

Link: https://lkml.kernel.org/r/20201026064021.3545418-6-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>

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: ::

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];
@@ -94,15 +94,15 @@ 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;
 		case PIN_FAST_BENCHMARK:
 			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;
@@ -157,10 +157,10 @@ 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;

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;

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;
+	unsigned long 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;
@@ -104,18 +122,31 @@ 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;