diff mbox series

[1/3] mm/gup_benchmark: Support threading

Message ID 20210506232537.165788-2-peterx@redhat.com (mailing list archive)
State New, archived
Headers show
Series mm/gup: Fix pin page write cache bouncing on has_pinned | expand

Commit Message

Peter Xu May 6, 2021, 11:25 p.m. UTC
Add a new parameter "-j N" to support concurrent gup test.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 tools/testing/selftests/vm/gup_test.c | 94 ++++++++++++++++++---------
 1 file changed, 63 insertions(+), 31 deletions(-)

Comments

John Hubbard May 7, 2021, 4:37 a.m. UTC | #1
On 5/6/21 4:25 PM, Peter Xu wrote:
> Add a new parameter "-j N" to support concurrent gup test.

I had a long-standing personal TODO item that said, "decide if it's
worth it, to add pthread support to gup_test". So now, at least one
other person has decided that it *is* worth it, and you've also written
the patch. OK, then. Sweet! :)

This looks correct to me. I have a couple of minor comments below, but
either way you can add:

Reviewed-by: John Hubbard <jhubbard@nvidia.com>


> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>   tools/testing/selftests/vm/gup_test.c | 94 ++++++++++++++++++---------
>   1 file changed, 63 insertions(+), 31 deletions(-)
> 
> diff --git a/tools/testing/selftests/vm/gup_test.c b/tools/testing/selftests/vm/gup_test.c
> index 1e662d59c502a..3f0fcc697c3fc 100644
> --- a/tools/testing/selftests/vm/gup_test.c
> +++ b/tools/testing/selftests/vm/gup_test.c
> @@ -6,6 +6,7 @@
>   #include <sys/mman.h>
>   #include <sys/stat.h>
>   #include <sys/types.h>
> +#include <pthread.h>
>   #include "../../../../mm/gup_test.h"
>   
>   #define MB (1UL << 20)
> @@ -15,6 +16,12 @@
>   #define FOLL_WRITE	0x01	/* check pte is writable */
>   #define FOLL_TOUCH	0x02	/* mark page accessed */
>   
> +static unsigned long cmd = GUP_FAST_BENCHMARK;
> +static int gup_fd, repeats = 1;
> +static unsigned long size = 128 * MB;
> +/* Serialize prints */
> +static pthread_mutex_t print_mutex = PTHREAD_MUTEX_INITIALIZER;
> +
>   static char *cmd_to_str(unsigned long cmd)
>   {
>   	switch (cmd) {
> @@ -34,17 +41,55 @@ static char *cmd_to_str(unsigned long cmd)
>   	return "Unknown command";
>   }
>   
> +void *gup_thread(void *data)
> +{
> +	struct gup_test gup = *(struct gup_test *)data;
> +	int 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(gup_fd, cmd, &gup))
> +				perror("ioctl"), exit(1);
> +
> +			pthread_mutex_lock(&print_mutex);
> +			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");
> +			pthread_mutex_unlock(&print_mutex);
> +		}
> +	} else {
> +		gup.size = size;
> +		if (ioctl(gup_fd, cmd, &gup)) {
> +			perror("ioctl");
> +			exit(1);
> +		}
> +
> +		pthread_mutex_lock(&print_mutex);
> +		printf("%s: done\n", cmd_to_str(cmd));
> +		if (gup.size != size)
> +			printf("Truncated (size: %lld)\n", gup.size);
> +		pthread_mutex_unlock(&print_mutex);
> +	}
> +
> +	return NULL;
> +}
> +
>   int main(int argc, char **argv)
>   {
>   	struct gup_test gup = { 0 };
> -	unsigned long size = 128 * MB;
> -	int i, fd, filed, opt, nr_pages = 1, thp = -1, repeats = 1, write = 1;
> -	unsigned long cmd = GUP_FAST_BENCHMARK;
> +	int filed, i, opt, nr_pages = 1, thp = -1, write = 1, threads = 1;


"nthreads" is a little more accurate for this.


>   	int flags = MAP_PRIVATE, touch = 0;
>   	char *file = "/dev/zero";
> +	pthread_t *tid;
>   	char *p;
>   
> -	while ((opt = getopt(argc, argv, "m:r:n:F:f:abctTLUuwWSHpz")) != -1) {
> +	while ((opt = getopt(argc, argv, "m:r:n:F:f:abcj:tTLUuwWSHpz")) != -1) {
>   		switch (opt) {
>   		case 'a':
>   			cmd = PIN_FAST_BENCHMARK;
> @@ -74,6 +119,9 @@ int main(int argc, char **argv)
>   			/* strtol, so you can pass flags in hex form */
>   			gup.gup_flags = strtol(optarg, 0, 0);
>   			break;
> +		case 'j':
> +			threads = atoi(optarg);
> +			break;
>   		case 'm':
>   			size = atoi(optarg) * MB;
>   			break;
> @@ -154,8 +202,8 @@ int main(int argc, char **argv)
>   	if (write)
>   		gup.gup_flags |= FOLL_WRITE;
>   
> -	fd = open("/sys/kernel/debug/gup_test", O_RDWR);
> -	if (fd == -1) {
> +	gup_fd = open("/sys/kernel/debug/gup_test", O_RDWR);
> +	if (gup_fd == -1) {
>   		perror("open");
>   		exit(1);
>   	}
> @@ -185,32 +233,16 @@ int main(int argc, char **argv)
>   			p[0] = 0;
>   	}
>   
> -	/* 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("%s: done\n", cmd_to_str(cmd));
> -		if (gup.size != size)
> -			printf("Truncated (size: %lld)\n", gup.size);
> +	tid = malloc(sizeof(pthread_t) * threads);
> +	if (!tid) {
> +		perror("malloc()");
> +		exit(1);
>   	}
> +	for (i = 0; i < threads; i++)
> +		pthread_create(&tid[i], NULL, gup_thread, &gup);

It might be nice to check the return value of pthread_create(), and
just exit out with an error if it fails. On the other hand, it seems
spectacularly unlikely for it to fail here...on the other-other hand,
I always say that, just before writing code that doesn't check an
error, and the error somehow happens anyway and costs someone some
wasted time.

Your call.

> +	for (i = 0; i < threads; i++)
> +		pthread_join(tid[i], NULL);
> +	free(tid);
>   
>   	return 0;
>   }
> 

thanks,
Peter Xu May 7, 2021, 2:04 p.m. UTC | #2
On Thu, May 06, 2021 at 09:37:37PM -0700, John Hubbard wrote:
> On 5/6/21 4:25 PM, Peter Xu wrote:
> > Add a new parameter "-j N" to support concurrent gup test.
> 
> I had a long-standing personal TODO item that said, "decide if it's
> worth it, to add pthread support to gup_test". So now, at least one
> other person has decided that it *is* worth it, and you've also written
> the patch. OK, then. Sweet! :)
> 
> This looks correct to me. I have a couple of minor comments below, but
> either way you can add:

I'll address them.

> 
> Reviewed-by: John Hubbard <jhubbard@nvidia.com>

Thanks!
diff mbox series

Patch

diff --git a/tools/testing/selftests/vm/gup_test.c b/tools/testing/selftests/vm/gup_test.c
index 1e662d59c502a..3f0fcc697c3fc 100644
--- a/tools/testing/selftests/vm/gup_test.c
+++ b/tools/testing/selftests/vm/gup_test.c
@@ -6,6 +6,7 @@ 
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <pthread.h>
 #include "../../../../mm/gup_test.h"
 
 #define MB (1UL << 20)
@@ -15,6 +16,12 @@ 
 #define FOLL_WRITE	0x01	/* check pte is writable */
 #define FOLL_TOUCH	0x02	/* mark page accessed */
 
+static unsigned long cmd = GUP_FAST_BENCHMARK;
+static int gup_fd, repeats = 1;
+static unsigned long size = 128 * MB;
+/* Serialize prints */
+static pthread_mutex_t print_mutex = PTHREAD_MUTEX_INITIALIZER;
+
 static char *cmd_to_str(unsigned long cmd)
 {
 	switch (cmd) {
@@ -34,17 +41,55 @@  static char *cmd_to_str(unsigned long cmd)
 	return "Unknown command";
 }
 
+void *gup_thread(void *data)
+{
+	struct gup_test gup = *(struct gup_test *)data;
+	int 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(gup_fd, cmd, &gup))
+				perror("ioctl"), exit(1);
+
+			pthread_mutex_lock(&print_mutex);
+			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");
+			pthread_mutex_unlock(&print_mutex);
+		}
+	} else {
+		gup.size = size;
+		if (ioctl(gup_fd, cmd, &gup)) {
+			perror("ioctl");
+			exit(1);
+		}
+
+		pthread_mutex_lock(&print_mutex);
+		printf("%s: done\n", cmd_to_str(cmd));
+		if (gup.size != size)
+			printf("Truncated (size: %lld)\n", gup.size);
+		pthread_mutex_unlock(&print_mutex);
+	}
+
+	return NULL;
+}
+
 int main(int argc, char **argv)
 {
 	struct gup_test gup = { 0 };
-	unsigned long size = 128 * MB;
-	int i, fd, filed, opt, nr_pages = 1, thp = -1, repeats = 1, write = 1;
-	unsigned long cmd = GUP_FAST_BENCHMARK;
+	int filed, i, opt, nr_pages = 1, thp = -1, write = 1, threads = 1;
 	int flags = MAP_PRIVATE, touch = 0;
 	char *file = "/dev/zero";
+	pthread_t *tid;
 	char *p;
 
-	while ((opt = getopt(argc, argv, "m:r:n:F:f:abctTLUuwWSHpz")) != -1) {
+	while ((opt = getopt(argc, argv, "m:r:n:F:f:abcj:tTLUuwWSHpz")) != -1) {
 		switch (opt) {
 		case 'a':
 			cmd = PIN_FAST_BENCHMARK;
@@ -74,6 +119,9 @@  int main(int argc, char **argv)
 			/* strtol, so you can pass flags in hex form */
 			gup.gup_flags = strtol(optarg, 0, 0);
 			break;
+		case 'j':
+			threads = atoi(optarg);
+			break;
 		case 'm':
 			size = atoi(optarg) * MB;
 			break;
@@ -154,8 +202,8 @@  int main(int argc, char **argv)
 	if (write)
 		gup.gup_flags |= FOLL_WRITE;
 
-	fd = open("/sys/kernel/debug/gup_test", O_RDWR);
-	if (fd == -1) {
+	gup_fd = open("/sys/kernel/debug/gup_test", O_RDWR);
+	if (gup_fd == -1) {
 		perror("open");
 		exit(1);
 	}
@@ -185,32 +233,16 @@  int main(int argc, char **argv)
 			p[0] = 0;
 	}
 
-	/* 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("%s: done\n", cmd_to_str(cmd));
-		if (gup.size != size)
-			printf("Truncated (size: %lld)\n", gup.size);
+	tid = malloc(sizeof(pthread_t) * threads);
+	if (!tid) {
+		perror("malloc()");
+		exit(1);
 	}
+	for (i = 0; i < threads; i++)
+		pthread_create(&tid[i], NULL, gup_thread, &gup);
+	for (i = 0; i < threads; i++)
+		pthread_join(tid[i], NULL);
+	free(tid);
 
 	return 0;
 }