[PATCH 0/2] Add af_inet mode besides af_unix and pipe

[PATCH 0/2] Add af_inet mode besides af_unix and pipe

[Yihao Wu]

Yihao Wu (2):
  hackbench: Fix negativity opt checking
  hackbench: Add af_inet mode besides af_unix and pipe

 src/hackbench/hackbench.c | 73 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 64 insertions(+), 9 deletions(-)

-- 
2.18.2

[PATCH 1/2] hackbench: Fix negativity opt checking

[Yihao Wu]

It was easy to escape the checking. For example, run

  ./hackbench --datasize 4096 -g -1 -l -1

This patch fixes the checking.

Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
---
 src/hackbench/hackbench.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
index 268c232..b9b0af6 100644
--- a/src/hackbench/hackbench.c
+++ b/src/hackbench/hackbench.c
@@ -31,10 +31,10 @@
 #include <setjmp.h>
 #include <sched.h>
 
-static unsigned int datasize = 100;
-static unsigned int loops = 100;
-static unsigned int num_groups = 10;
-static unsigned int num_fds = 20;
+static int datasize = 100;
+static int loops = 100;
+static int num_groups = 10;
+static int num_fds = 20;
 static unsigned int fifo = 0;
 
 /*
@@ -377,7 +377,7 @@ static void process_options(int argc, char *argv[])
 		}
 		switch (c) {
 		case 'f':
-			if (!(argv[optind] && (num_fds = atoi(optarg)) > 0)) {
+			if ((num_fds = atoi(optarg)) <= 0) {
 				fprintf(stderr, "%s: --fds|-f requires an integer > 0\n", argv[0]);
 				print_usage_exit(1);
 			}
@@ -386,7 +386,7 @@ static void process_options(int argc, char *argv[])
 			fifo = 1;
 			break;
 		case 'g':
-			if (!(argv[optind] && (num_groups = atoi(optarg)) > 0)) {
+			if ((num_groups = atoi(optarg)) <= 0) {
 				fprintf(stderr, "%s: --groups|-g requires an integer > 0\n", argv[0]);
 				print_usage_exit(1);
 			}
@@ -394,7 +394,7 @@ static void process_options(int argc, char *argv[])
 		case 'h':
 			print_usage_exit(0);
 		case 'l':
-			if (!(argv[optind] && (loops = atoi(optarg)) > 0)) {
+			if ((loops = atoi(optarg)) <= 0) {
 				fprintf(stderr, "%s: --loops|-l requires an integer > 0\n", argv[0]);
 				print_usage_exit(1);
 			}
@@ -403,7 +403,7 @@ static void process_options(int argc, char *argv[])
 			use_pipes = 1;
 			break;
 		case 's':
-			if (!(argv[optind] && (datasize = atoi(optarg)) > 0)) {
+			if ((datasize = atoi(optarg)) <= 0) {
 				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
 				print_usage_exit(1);
 			}
-- 
2.18.2

Re: [PATCH 1/2] hackbench: Fix negativity opt checking

[John Kacur]

On Thu, 28 Apr 2022, Yihao Wu wrote:

> It was easy to escape the checking. For example, run
> 
>   ./hackbench --datasize 4096 -g -1 -l -1
> 
> This patch fixes the checking.
> 
> Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
> ---
>  src/hackbench/hackbench.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
> index 268c232..b9b0af6 100644
> --- a/src/hackbench/hackbench.c
> +++ b/src/hackbench/hackbench.c
> @@ -31,10 +31,10 @@
>  #include <setjmp.h>
>  #include <sched.h>
>  
> -static unsigned int datasize = 100;
> -static unsigned int loops = 100;
> -static unsigned int num_groups = 10;
> -static unsigned int num_fds = 20;
> +static int datasize = 100;
> +static int loops = 100;
> +static int num_groups = 10;
> +static int num_fds = 20;
>  static unsigned int fifo = 0;
>  
>  /*
> @@ -377,7 +377,7 @@ static void process_options(int argc, char *argv[])
>  		}
>  		switch (c) {
>  		case 'f':
> -			if (!(argv[optind] && (num_fds = atoi(optarg)) > 0)) {
> +			if ((num_fds = atoi(optarg)) <= 0) {
>  				fprintf(stderr, "%s: --fds|-f requires an integer > 0\n", argv[0]);
>  				print_usage_exit(1);
>  			}
> @@ -386,7 +386,7 @@ static void process_options(int argc, char *argv[])
>  			fifo = 1;
>  			break;
>  		case 'g':
> -			if (!(argv[optind] && (num_groups = atoi(optarg)) > 0)) {
> +			if ((num_groups = atoi(optarg)) <= 0) {
>  				fprintf(stderr, "%s: --groups|-g requires an integer > 0\n", argv[0]);
>  				print_usage_exit(1);
>  			}
> @@ -394,7 +394,7 @@ static void process_options(int argc, char *argv[])
>  		case 'h':
>  			print_usage_exit(0);
>  		case 'l':
> -			if (!(argv[optind] && (loops = atoi(optarg)) > 0)) {
> +			if ((loops = atoi(optarg)) <= 0) {
>  				fprintf(stderr, "%s: --loops|-l requires an integer > 0\n", argv[0]);
>  				print_usage_exit(1);
>  			}
> @@ -403,7 +403,7 @@ static void process_options(int argc, char *argv[])
>  			use_pipes = 1;
>  			break;
>  		case 's':
> -			if (!(argv[optind] && (datasize = atoi(optarg)) > 0)) {
> +			if ((datasize = atoi(optarg)) <= 0) {
>  				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
>  				print_usage_exit(1);
>  			}
> -- 
> 2.18.2
> 
> 

Well, the code doesn't work the way the author intended, that's for sure.
As your patch indicates, you realize the problem is that an unsigned 
variable can never be less than zero, so the check is meaningless. 
However, is changing the data type the right solution, just to make a 
check against something stupid a user might input the correct thing to do? 
It decreases the size of valid input. Maybe that doesn't matter, but then 
could it introduce a new bug somewhere? You've dropped the argv[optind] 
too which also doesn't work the way the author intended, but it was 
probably meant as a check of whether the user provided an argument or not.

What I would rather see if you want to fix this, is a check against the 
user input that doesn't change the datatype. For example, if you treat the 
input as a char, if (optarg[0] == '-') then we can tell the difference 
between a really big number or user input that is stupid or malicious.
If you look in cyclictest, (there could be bugs lurking there too), there 
is an attempt to parse this kind of thing and to check whether there are 
arguments too.

Thanks

John

Re: [PATCH 1/2] hackbench: Fix negativity opt checking

[Yihao Wu]

I'm sorry! John. In the commit log, I described the problem wrong. It 
should be more trivially reproduced like this,

./hackbench --datasize 4096 -g 1 -l 1

This command gives an error "--datasize|-s requires an integer > 0". But 
if you append any argument (or nonsense) after this command, like,

./hackbench --datasize 4096 -g 1 -l 1 whatever

This command runs without any error message.

My original intention of this patch was to remove "!(argv[optind]". I 
suppose this condition leads to this bug. (Pardon me for I don't know 
what's it for. I'd admit I'm not familiar with getopt)

This negative bugfix should only be a piggypack fix. But as you've 
pointed out, it merely hides misusage. So it's a bad bugfix.

Thanks,

Yihao

On 2022/5/10 02:59, John Kacur wrote:
> Well, the code doesn't work the way the author intended, that's for sure.
> As your patch indicates, you realize the problem is that an unsigned
> variable can never be less than zero, so the check is meaningless.
> However, is changing the data type the right solution, just to make a
> check against something stupid a user might input the correct thing to do?
> It decreases the size of valid input. Maybe that doesn't matter, but then
> could it introduce a new bug somewhere? You've dropped the argv[optind]
> too which also doesn't work the way the author intended, but it was
> probably meant as a check of whether the user provided an argument or not.
> 
> What I would rather see if you want to fix this, is a check against the
> user input that doesn't change the datatype. For example, if you treat the
> input as a char, if (optarg[0] == '-') then we can tell the difference
> between a really big number or user input that is stupid or malicious.
> If you look in cyclictest, (there could be bugs lurking there too), there
> is an attempt to parse this kind of thing and to check whether there are
> arguments too.
> 
> Thanks
> 
> John

[PATCH 2/2] hackbench: Add af_inet mode besides af_unix and pipe

[Yihao Wu]

We observerved strange performance regression with hackbench, but only with
its default mode instead of pipe mode. It turned out it was unix domain
socket to blame rather than the scheduler. Because on older kernels, there
was a big lock. And modifications to the scheduler made the contension
worse.

However pipe mode is much different from the default af_unix mode. So it's
hard to prove it's really the case. So we think it might be a good idea to
have af_inet mode for hackbench.

After implementing it, we compare these three modes. And the result shows
as what we expect, that only af_unix mode has regression, the others don't.
This proves adding af_inet mode is valuable.

Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
---
 src/hackbench/hackbench.c | 57 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
index b9b0af6..030342f 100644
--- a/src/hackbench/hackbench.c
+++ b/src/hackbench/hackbench.c
@@ -20,11 +20,14 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
+#include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
 #include <sys/time.h>
 #include <sys/poll.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 #include <limits.h>
 #include <getopt.h>
 #include <signal.h>
@@ -46,6 +49,7 @@ static unsigned int fifo = 0;
 static unsigned int process_mode = PROCESS_MODE;
 
 static int use_pipes = 0;
+static int use_inet = 0;
 
 struct sender_context {
 	unsigned int num_fds;
@@ -99,6 +103,7 @@ static void print_usage_exit(int error)
 	       "-h       --help            print this message\n"
 	       "-l       --loops=LOOPS     how many message should be send\n"
 	       "-p       --pipe            send data via a pipe\n"
+	       "-i       --inet            send data via a inet tcp connection\n"
 	       "-s       --datasize=SIZE   message size\n"
 	       "-T       --threads         use POSIX threads\n"
 	       "-P       --process         use fork (default)\n"
@@ -106,11 +111,52 @@ static void print_usage_exit(int error)
 	exit(error);
 }
 
+static int inet_socketpair(int fds[2])
+{
+	int s1, s2;
+	struct sockaddr_in sin;
+	unsigned long ul = 1;
+
+	if ((s1 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		barf("socket");
+	if ((s2 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		barf("socket");
+
+	socklen_t len = sizeof(sin);
+	bzero(&sin, len);
+	sin.sin_family = AF_INET;
+	sin.sin_port = 0;
+	sin.sin_addr.s_addr = inet_addr("127.0.0.1");
+
+	if (bind(s1, &sin, len) < 0)
+		barf("bind");
+	getsockname(s1, &sin, &len);
+	if (listen(s1, 10) < 0)
+		barf("listen");
+	if (ioctl(s2, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	if (ioctl(s1, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	connect(s2, &sin, len);
+	if ((fds[0] = accept(s1, &sin, &len)) < 0)
+		barf("accept");
+	ul = 0;
+	if (ioctl(s2, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	fds[1] = s2;
+	close(s1);
+
+	return 0;
+}
+
 static void fdpair(int fds[2])
 {
 	if (use_pipes) {
 		if (pipe(fds) == 0)
 			return;
+	} else if (use_inet) {
+		if (inet_socketpair(fds) == 0)
+			return;
 	} else {
 		if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
 			return;
@@ -364,13 +410,14 @@ static void process_options(int argc, char *argv[])
 			{"help",	no_argument,		NULL, 'h'},
 			{"loops",	required_argument,	NULL, 'l'},
 			{"pipe",	no_argument,		NULL, 'p'},
+			{"inet",	no_argument,		NULL, 'i'},
 			{"datasize",	required_argument,	NULL, 's'},
 			{"threads",	no_argument,		NULL, 'T'},
 			{"processes",	no_argument,		NULL, 'P'},
 			{NULL, 0, NULL, 0}
 		};
 
-		int c = getopt_long(argc, argv, "f:Fg:hl:ps:TP",
+		int c = getopt_long(argc, argv, "f:Fg:hl:pis:TP",
 				    longopts, &optind);
 		if (c == -1) {
 			break;
@@ -402,6 +449,9 @@ static void process_options(int argc, char *argv[])
 		case 'p':
 			use_pipes = 1;
 			break;
+		case 'i':
+			use_inet = 1;
+			break;
 		case 's':
 			if ((datasize = atoi(optarg)) <= 0) {
 				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
@@ -418,6 +468,11 @@ static void process_options(int argc, char *argv[])
 			print_usage_exit(1);
 		}
 	}
+
+	if (use_pipes && use_inet) {
+		fprintf(stderr, "%s: --pipe|-p and --inet|-i cannot be used together\n", argv[0]);
+		print_usage_exit(1);
+	}
 }
 
 void sigcatcher(int sig) {
-- 
2.18.2

Re: [PATCH 2/2] hackbench: Add af_inet mode besides af_unix and pipe

[John Kacur]

On Thu, 28 Apr 2022, Yihao Wu wrote:

> We observerved strange performance regression with hackbench, but only with
> its default mode instead of pipe mode. It turned out it was unix domain
> socket to blame rather than the scheduler. Because on older kernels, there
> was a big lock. And modifications to the scheduler made the contension
> worse.
> 
> However pipe mode is much different from the default af_unix mode. So it's
> hard to prove it's really the case. So we think it might be a good idea to
> have af_inet mode for hackbench.
> 
> After implementing it, we compare these three modes. And the result shows
> as what we expect, that only af_unix mode has regression, the others don't.
> This proves adding af_inet mode is valuable.
> 
> Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
> ---
>  src/hackbench/hackbench.c | 57 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
> index b9b0af6..030342f 100644
> --- a/src/hackbench/hackbench.c
> +++ b/src/hackbench/hackbench.c
> @@ -20,11 +20,14 @@
>  #include <string.h>
>  #include <errno.h>
>  #include <unistd.h>
> +#include <sys/ioctl.h>
>  #include <sys/types.h>
>  #include <sys/socket.h>
>  #include <sys/wait.h>
>  #include <sys/time.h>
>  #include <sys/poll.h>
> +#include <netinet/in.h>
> +#include <arpa/inet.h>
>  #include <limits.h>
>  #include <getopt.h>
>  #include <signal.h>
> @@ -46,6 +49,7 @@ static unsigned int fifo = 0;
>  static unsigned int process_mode = PROCESS_MODE;
>  
>  static int use_pipes = 0;
> +static int use_inet = 0;
>  
>  struct sender_context {
>  	unsigned int num_fds;
> @@ -99,6 +103,7 @@ static void print_usage_exit(int error)
>  	       "-h       --help            print this message\n"
>  	       "-l       --loops=LOOPS     how many message should be send\n"
>  	       "-p       --pipe            send data via a pipe\n"
> +	       "-i       --inet            send data via a inet tcp connection\n"
>  	       "-s       --datasize=SIZE   message size\n"
>  	       "-T       --threads         use POSIX threads\n"
>  	       "-P       --process         use fork (default)\n"
> @@ -106,11 +111,52 @@ static void print_usage_exit(int error)
>  	exit(error);
>  }
>  
> +static int inet_socketpair(int fds[2])
> +{
> +	int s1, s2;
> +	struct sockaddr_in sin;
> +	unsigned long ul = 1;
> +
> +	if ((s1 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
> +		barf("socket");
> +	if ((s2 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
> +		barf("socket");
> +
> +	socklen_t len = sizeof(sin);
> +	bzero(&sin, len);
> +	sin.sin_family = AF_INET;
> +	sin.sin_port = 0;
> +	sin.sin_addr.s_addr = inet_addr("127.0.0.1");
> +
> +	if (bind(s1, &sin, len) < 0)
> +		barf("bind");
> +	getsockname(s1, &sin, &len);
> +	if (listen(s1, 10) < 0)
> +		barf("listen");
> +	if (ioctl(s2, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	if (ioctl(s1, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	connect(s2, &sin, len);
> +	if ((fds[0] = accept(s1, &sin, &len)) < 0)
> +		barf("accept");
> +	ul = 0;
> +	if (ioctl(s2, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	fds[1] = s2;
> +	close(s1);
> +
> +	return 0;
> +}
> +
>  static void fdpair(int fds[2])
>  {
>  	if (use_pipes) {
>  		if (pipe(fds) == 0)
>  			return;
> +	} else if (use_inet) {
> +		if (inet_socketpair(fds) == 0)
> +			return;
>  	} else {
>  		if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
>  			return;
> @@ -364,13 +410,14 @@ static void process_options(int argc, char *argv[])
>  			{"help",	no_argument,		NULL, 'h'},
>  			{"loops",	required_argument,	NULL, 'l'},
>  			{"pipe",	no_argument,		NULL, 'p'},
> +			{"inet",	no_argument,		NULL, 'i'},
>  			{"datasize",	required_argument,	NULL, 's'},
>  			{"threads",	no_argument,		NULL, 'T'},
>  			{"processes",	no_argument,		NULL, 'P'},
>  			{NULL, 0, NULL, 0}
>  		};
>  
> -		int c = getopt_long(argc, argv, "f:Fg:hl:ps:TP",
> +		int c = getopt_long(argc, argv, "f:Fg:hl:pis:TP",
>  				    longopts, &optind);
>  		if (c == -1) {
>  			break;
> @@ -402,6 +449,9 @@ static void process_options(int argc, char *argv[])
>  		case 'p':
>  			use_pipes = 1;
>  			break;
> +		case 'i':
> +			use_inet = 1;
> +			break;
>  		case 's':
>  			if ((datasize = atoi(optarg)) <= 0) {
>  				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
> @@ -418,6 +468,11 @@ static void process_options(int argc, char *argv[])
>  			print_usage_exit(1);
>  		}
>  	}
> +
> +	if (use_pipes && use_inet) {
> +		fprintf(stderr, "%s: --pipe|-p and --inet|-i cannot be used together\n", argv[0]);
> +		print_usage_exit(1);
> +	}
>  }
>  
>  void sigcatcher(int sig) {
> -- 
> 2.18.2
> 
> 

Sure, this seems like a good idea. If I understand correctly, it doesn't 
change the default way that hackbench is run today without the option. 
I'll take this, but it doesn't apply correctly today, probably 
because it assumes that your first patch was applied. Could you regenerate 
this patch, against the current code without your first patch, and I'll 
apply it then.

Thanks

John

[PATCH v2] hackbench: Add af_inet mode besides af_unix and pipe

[Yihao Wu]

We observerved strange performance regression with hackbench, but only 
with its default mode instead of pipe mode. It turned out it was unix 
domain socket to blame rather than the scheduler. Because on older 
kernels, there was a big lock. And modifications to the scheduler made 
the contension worse.

However pipe mode is much different from the default af_unix mode. So 
it's hard to prove it's really the case. So we think it might be a good 
idea to have af_inet mode for hackbench.

After implementing it, we compare these three modes. And the result 
shows as what we expect, that only af_unix mode has regression, the 
others don't. This proves adding af_inet mode is valuable.

Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
---
  src/hackbench/hackbench.c | 57 ++++++++++++++++++++++++++++++++++++++-
  1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
index 268c232..18c9284 100644
--- a/src/hackbench/hackbench.c
+++ b/src/hackbench/hackbench.c
@@ -20,11 +20,14 @@
  #include <string.h>
  #include <errno.h>
  #include <unistd.h>
+#include <sys/ioctl.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <sys/wait.h>
  #include <sys/time.h>
  #include <sys/poll.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
  #include <limits.h>
  #include <getopt.h>
  #include <signal.h>
@@ -46,6 +49,7 @@ static unsigned int fifo = 0;
  static unsigned int process_mode = PROCESS_MODE;

  static int use_pipes = 0;
+static int use_inet = 0;

  struct sender_context {
  	unsigned int num_fds;
@@ -99,6 +103,7 @@ static void print_usage_exit(int error)
  	       "-h       --help            print this message\n"
  	       "-l       --loops=LOOPS     how many message should be send\n"
  	       "-p       --pipe            send data via a pipe\n"
+	       "-i       --inet            send data via a inet tcp connection\n"
  	       "-s       --datasize=SIZE   message size\n"
  	       "-T       --threads         use POSIX threads\n"
  	       "-P       --process         use fork (default)\n"
@@ -106,11 +111,52 @@ static void print_usage_exit(int error)
  	exit(error);
  }

+static int inet_socketpair(int fds[2])
+{
+	int s1, s2;
+	struct sockaddr_in sin;
+	unsigned long ul = 1;
+
+	if ((s1 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		barf("socket");
+	if ((s2 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		barf("socket");
+
+	socklen_t len = sizeof(sin);
+	bzero(&sin, len);
+	sin.sin_family = AF_INET;
+	sin.sin_port = 0;
+	sin.sin_addr.s_addr = inet_addr("127.0.0.1");
+
+	if (bind(s1, &sin, len) < 0)
+		barf("bind");
+	getsockname(s1, &sin, &len);
+	if (listen(s1, 10) < 0)
+		barf("listen");
+	if (ioctl(s2, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	if (ioctl(s1, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	connect(s2, &sin, len);
+	if ((fds[0] = accept(s1, &sin, &len)) < 0)
+		barf("accept");
+	ul = 0;
+	if (ioctl(s2, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	fds[1] = s2;
+	close(s1);
+
+	return 0;
+}
+
  static void fdpair(int fds[2])
  {
  	if (use_pipes) {
  		if (pipe(fds) == 0)
  			return;
+	} else if (use_inet) {
+		if (inet_socketpair(fds) == 0)
+			return;
  	} else {
  		if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
  			return;
@@ -364,13 +410,14 @@ static void process_options(int argc, char *argv[])
  			{"help",	no_argument,		NULL, 'h'},
  			{"loops",	required_argument,	NULL, 'l'},
  			{"pipe",	no_argument,		NULL, 'p'},
+			{"inet",	no_argument,		NULL, 'i'},
  			{"datasize",	required_argument,	NULL, 's'},
  			{"threads",	no_argument,		NULL, 'T'},
  			{"processes",	no_argument,		NULL, 'P'},
  			{NULL, 0, NULL, 0}
  		};

-		int c = getopt_long(argc, argv, "f:Fg:hl:ps:TP",
+		int c = getopt_long(argc, argv, "f:Fg:hl:pis:TP",
  				    longopts, &optind);
  		if (c == -1) {
  			break;
@@ -402,6 +449,9 @@ static void process_options(int argc, char *argv[])
  		case 'p':
  			use_pipes = 1;
  			break;
+		case 'i':
+			use_inet = 1;
+			break;
  		case 's':
  			if (!(argv[optind] && (datasize = atoi(optarg)) > 0)) {
  				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", 
argv[0]);
@@ -418,6 +468,11 @@ static void process_options(int argc, char *argv[])
  			print_usage_exit(1);
  		}
  	}
+
+	if (use_pipes && use_inet) {
+		fprintf(stderr, "%s: --pipe|-p and --inet|-i cannot be used 
together\n", argv[0]);
+		print_usage_exit(1);
+	}
  }

  void sigcatcher(int sig) {
--
2.32.0.604.gb1f3e1269

[PATCH v3] hackbench: Add af_inet mode besides af_unix and pipe

[Yihao Wu]

We observerved strange performance regression with hackbench, but only with
its default mode instead of pipe mode. It turned out it was unix domain
socket to blame rather than the scheduler. Because on older kernels, there
was a big lock. And modifications to the scheduler made the contension
worse.

However pipe mode is much different from the default af_unix mode. So it's
hard to prove it's really the case. So we think it might be a good idea to
have af_inet mode for hackbench.

After implementing it, we compare these three modes. And the result shows
as what we expect, that only af_unix mode has regression, the others don't.
This proves adding af_inet mode is valuable.

Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
---
v1->v2: Drop the first patch
v2->v3: Fix EOLs in the commit log

 src/hackbench/hackbench.c | 57 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
index 268c232..18c9284 100644
--- a/src/hackbench/hackbench.c
+++ b/src/hackbench/hackbench.c
@@ -20,11 +20,14 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
+#include <sys/ioctl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
 #include <sys/time.h>
 #include <sys/poll.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 #include <limits.h>
 #include <getopt.h>
 #include <signal.h>
@@ -46,6 +49,7 @@ static unsigned int fifo = 0;
 static unsigned int process_mode = PROCESS_MODE;
 
 static int use_pipes = 0;
+static int use_inet = 0;
 
 struct sender_context {
 	unsigned int num_fds;
@@ -99,6 +103,7 @@ static void print_usage_exit(int error)
 	       "-h       --help            print this message\n"
 	       "-l       --loops=LOOPS     how many message should be send\n"
 	       "-p       --pipe            send data via a pipe\n"
+	       "-i       --inet            send data via a inet tcp connection\n"
 	       "-s       --datasize=SIZE   message size\n"
 	       "-T       --threads         use POSIX threads\n"
 	       "-P       --process         use fork (default)\n"
@@ -106,11 +111,52 @@ static void print_usage_exit(int error)
 	exit(error);
 }
 
+static int inet_socketpair(int fds[2])
+{
+	int s1, s2;
+	struct sockaddr_in sin;
+	unsigned long ul = 1;
+
+	if ((s1 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		barf("socket");
+	if ((s2 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+		barf("socket");
+
+	socklen_t len = sizeof(sin);
+	bzero(&sin, len);
+	sin.sin_family = AF_INET;
+	sin.sin_port = 0;
+	sin.sin_addr.s_addr = inet_addr("127.0.0.1");
+
+	if (bind(s1, &sin, len) < 0)
+		barf("bind");
+	getsockname(s1, &sin, &len);
+	if (listen(s1, 10) < 0)
+		barf("listen");
+	if (ioctl(s2, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	if (ioctl(s1, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	connect(s2, &sin, len);
+	if ((fds[0] = accept(s1, &sin, &len)) < 0)
+		barf("accept");
+	ul = 0;
+	if (ioctl(s2, FIONBIO, &ul) < 0)
+		barf("ioctl");
+	fds[1] = s2;
+	close(s1);
+
+	return 0;
+}
+
 static void fdpair(int fds[2])
 {
 	if (use_pipes) {
 		if (pipe(fds) == 0)
 			return;
+	} else if (use_inet) {
+		if (inet_socketpair(fds) == 0)
+			return;
 	} else {
 		if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
 			return;
@@ -364,13 +410,14 @@ static void process_options(int argc, char *argv[])
 			{"help",	no_argument,		NULL, 'h'},
 			{"loops",	required_argument,	NULL, 'l'},
 			{"pipe",	no_argument,		NULL, 'p'},
+			{"inet",	no_argument,		NULL, 'i'},
 			{"datasize",	required_argument,	NULL, 's'},
 			{"threads",	no_argument,		NULL, 'T'},
 			{"processes",	no_argument,		NULL, 'P'},
 			{NULL, 0, NULL, 0}
 		};
 
-		int c = getopt_long(argc, argv, "f:Fg:hl:ps:TP",
+		int c = getopt_long(argc, argv, "f:Fg:hl:pis:TP",
 				    longopts, &optind);
 		if (c == -1) {
 			break;
@@ -402,6 +449,9 @@ static void process_options(int argc, char *argv[])
 		case 'p':
 			use_pipes = 1;
 			break;
+		case 'i':
+			use_inet = 1;
+			break;
 		case 's':
 			if (!(argv[optind] && (datasize = atoi(optarg)) > 0)) {
 				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
@@ -418,6 +468,11 @@ static void process_options(int argc, char *argv[])
 			print_usage_exit(1);
 		}
 	}
+
+	if (use_pipes && use_inet) {
+		fprintf(stderr, "%s: --pipe|-p and --inet|-i cannot be used together\n", argv[0]);
+		print_usage_exit(1);
+	}
 }
 
 void sigcatcher(int sig) {
-- 
2.32.0.604.gb1f3e1269

Re: [PATCH v3] hackbench: Add af_inet mode besides af_unix and pipe

[John Kacur]

On Mon, 23 May 2022, Yihao Wu wrote:

> We observerved strange performance regression with hackbench, but only with
> its default mode instead of pipe mode. It turned out it was unix domain
> socket to blame rather than the scheduler. Because on older kernels, there
> was a big lock. And modifications to the scheduler made the contension
> worse.
> 
> However pipe mode is much different from the default af_unix mode. So it's
> hard to prove it's really the case. So we think it might be a good idea to
> have af_inet mode for hackbench.
> 
> After implementing it, we compare these three modes. And the result shows
> as what we expect, that only af_unix mode has regression, the others don't.
> This proves adding af_inet mode is valuable.
> 
> Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
> ---
> v1->v2: Drop the first patch
> v2->v3: Fix EOLs in the commit log
> 
>  src/hackbench/hackbench.c | 57 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
> index 268c232..18c9284 100644
> --- a/src/hackbench/hackbench.c
> +++ b/src/hackbench/hackbench.c
> @@ -20,11 +20,14 @@
>  #include <string.h>
>  #include <errno.h>
>  #include <unistd.h>
> +#include <sys/ioctl.h>
>  #include <sys/types.h>
>  #include <sys/socket.h>
>  #include <sys/wait.h>
>  #include <sys/time.h>
>  #include <sys/poll.h>
> +#include <netinet/in.h>
> +#include <arpa/inet.h>
>  #include <limits.h>
>  #include <getopt.h>
>  #include <signal.h>
> @@ -46,6 +49,7 @@ static unsigned int fifo = 0;
>  static unsigned int process_mode = PROCESS_MODE;
>  
>  static int use_pipes = 0;
> +static int use_inet = 0;
>  
>  struct sender_context {
>  	unsigned int num_fds;
> @@ -99,6 +103,7 @@ static void print_usage_exit(int error)
>  	       "-h       --help            print this message\n"
>  	       "-l       --loops=LOOPS     how many message should be send\n"
>  	       "-p       --pipe            send data via a pipe\n"
> +	       "-i       --inet            send data via a inet tcp connection\n"
>  	       "-s       --datasize=SIZE   message size\n"
>  	       "-T       --threads         use POSIX threads\n"
>  	       "-P       --process         use fork (default)\n"
> @@ -106,11 +111,52 @@ static void print_usage_exit(int error)
>  	exit(error);
>  }
>  
> +static int inet_socketpair(int fds[2])
> +{
> +	int s1, s2;
> +	struct sockaddr_in sin;
> +	unsigned long ul = 1;
> +
> +	if ((s1 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
> +		barf("socket");
> +	if ((s2 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
> +		barf("socket");
> +
> +	socklen_t len = sizeof(sin);
> +	bzero(&sin, len);
> +	sin.sin_family = AF_INET;
> +	sin.sin_port = 0;
> +	sin.sin_addr.s_addr = inet_addr("127.0.0.1");
> +
> +	if (bind(s1, &sin, len) < 0)
> +		barf("bind");
> +	getsockname(s1, &sin, &len);
> +	if (listen(s1, 10) < 0)
> +		barf("listen");
> +	if (ioctl(s2, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	if (ioctl(s1, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	connect(s2, &sin, len);
> +	if ((fds[0] = accept(s1, &sin, &len)) < 0)
> +		barf("accept");
> +	ul = 0;
> +	if (ioctl(s2, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	fds[1] = s2;
> +	close(s1);
> +
> +	return 0;
> +}
> +
>  static void fdpair(int fds[2])
>  {
>  	if (use_pipes) {
>  		if (pipe(fds) == 0)
>  			return;
> +	} else if (use_inet) {
> +		if (inet_socketpair(fds) == 0)
> +			return;
>  	} else {
>  		if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
>  			return;
> @@ -364,13 +410,14 @@ static void process_options(int argc, char *argv[])
>  			{"help",	no_argument,		NULL, 'h'},
>  			{"loops",	required_argument,	NULL, 'l'},
>  			{"pipe",	no_argument,		NULL, 'p'},
> +			{"inet",	no_argument,		NULL, 'i'},
>  			{"datasize",	required_argument,	NULL, 's'},
>  			{"threads",	no_argument,		NULL, 'T'},
>  			{"processes",	no_argument,		NULL, 'P'},
>  			{NULL, 0, NULL, 0}
>  		};
>  
> -		int c = getopt_long(argc, argv, "f:Fg:hl:ps:TP",
> +		int c = getopt_long(argc, argv, "f:Fg:hl:pis:TP",
>  				    longopts, &optind);
>  		if (c == -1) {
>  			break;
> @@ -402,6 +449,9 @@ static void process_options(int argc, char *argv[])
>  		case 'p':
>  			use_pipes = 1;
>  			break;
> +		case 'i':
> +			use_inet = 1;
> +			break;
>  		case 's':
>  			if (!(argv[optind] && (datasize = atoi(optarg)) > 0)) {
>  				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
> @@ -418,6 +468,11 @@ static void process_options(int argc, char *argv[])
>  			print_usage_exit(1);
>  		}
>  	}
> +
> +	if (use_pipes && use_inet) {
> +		fprintf(stderr, "%s: --pipe|-p and --inet|-i cannot be used together\n", argv[0]);
> +		print_usage_exit(1);
> +	}
>  }
>  
>  void sigcatcher(int sig) {
> -- 
> 2.32.0.604.gb1f3e1269
> 
> 
Signed-off-by: John Kacur <jkacur@redhat.com>

Re: [PATCH 2/2] hackbench: Add af_inet mode besides af_unix and pipe

[Yihao Wu]

Hi John,

I regenerated the second patch and sent it to you. Now it should be 
applied successfully without the first patch.

Thanks a lot for your patient reviewing and comments!

Yihao

On 2022/4/28 18:37, Yihao Wu wrote:
> We observerved strange performance regression with hackbench, but only with
> its default mode instead of pipe mode. It turned out it was unix domain
> socket to blame rather than the scheduler. Because on older kernels, there
> was a big lock. And modifications to the scheduler made the contension
> worse.
> 
> However pipe mode is much different from the default af_unix mode. So it's
> hard to prove it's really the case. So we think it might be a good idea to
> have af_inet mode for hackbench.
> 
> After implementing it, we compare these three modes. And the result shows
> as what we expect, that only af_unix mode has regression, the others don't.
> This proves adding af_inet mode is valuable.
> 
> Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
> ---
>   src/hackbench/hackbench.c | 57 ++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/src/hackbench/hackbench.c b/src/hackbench/hackbench.c
> index b9b0af6..030342f 100644
> --- a/src/hackbench/hackbench.c
> +++ b/src/hackbench/hackbench.c
> @@ -20,11 +20,14 @@
>   #include <string.h>
>   #include <errno.h>
>   #include <unistd.h>
> +#include <sys/ioctl.h>
>   #include <sys/types.h>
>   #include <sys/socket.h>
>   #include <sys/wait.h>
>   #include <sys/time.h>
>   #include <sys/poll.h>
> +#include <netinet/in.h>
> +#include <arpa/inet.h>
>   #include <limits.h>
>   #include <getopt.h>
>   #include <signal.h>
> @@ -46,6 +49,7 @@ static unsigned int fifo = 0;
>   static unsigned int process_mode = PROCESS_MODE;
>   
>   static int use_pipes = 0;
> +static int use_inet = 0;
>   
>   struct sender_context {
>   	unsigned int num_fds;
> @@ -99,6 +103,7 @@ static void print_usage_exit(int error)
>   	       "-h       --help            print this message\n"
>   	       "-l       --loops=LOOPS     how many message should be send\n"
>   	       "-p       --pipe            send data via a pipe\n"
> +	       "-i       --inet            send data via a inet tcp connection\n"
>   	       "-s       --datasize=SIZE   message size\n"
>   	       "-T       --threads         use POSIX threads\n"
>   	       "-P       --process         use fork (default)\n"
> @@ -106,11 +111,52 @@ static void print_usage_exit(int error)
>   	exit(error);
>   }
>   
> +static int inet_socketpair(int fds[2])
> +{
> +	int s1, s2;
> +	struct sockaddr_in sin;
> +	unsigned long ul = 1;
> +
> +	if ((s1 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
> +		barf("socket");
> +	if ((s2 = socket(AF_INET, SOCK_STREAM, 0)) < 0)
> +		barf("socket");
> +
> +	socklen_t len = sizeof(sin);
> +	bzero(&sin, len);
> +	sin.sin_family = AF_INET;
> +	sin.sin_port = 0;
> +	sin.sin_addr.s_addr = inet_addr("127.0.0.1");
> +
> +	if (bind(s1, &sin, len) < 0)
> +		barf("bind");
> +	getsockname(s1, &sin, &len);
> +	if (listen(s1, 10) < 0)
> +		barf("listen");
> +	if (ioctl(s2, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	if (ioctl(s1, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	connect(s2, &sin, len);
> +	if ((fds[0] = accept(s1, &sin, &len)) < 0)
> +		barf("accept");
> +	ul = 0;
> +	if (ioctl(s2, FIONBIO, &ul) < 0)
> +		barf("ioctl");
> +	fds[1] = s2;
> +	close(s1);
> +
> +	return 0;
> +}
> +
>   static void fdpair(int fds[2])
>   {
>   	if (use_pipes) {
>   		if (pipe(fds) == 0)
>   			return;
> +	} else if (use_inet) {
> +		if (inet_socketpair(fds) == 0)
> +			return;
>   	} else {
>   		if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
>   			return;
> @@ -364,13 +410,14 @@ static void process_options(int argc, char *argv[])
>   			{"help",	no_argument,		NULL, 'h'},
>   			{"loops",	required_argument,	NULL, 'l'},
>   			{"pipe",	no_argument,		NULL, 'p'},
> +			{"inet",	no_argument,		NULL, 'i'},
>   			{"datasize",	required_argument,	NULL, 's'},
>   			{"threads",	no_argument,		NULL, 'T'},
>   			{"processes",	no_argument,		NULL, 'P'},
>   			{NULL, 0, NULL, 0}
>   		};
>   
> -		int c = getopt_long(argc, argv, "f:Fg:hl:ps:TP",
> +		int c = getopt_long(argc, argv, "f:Fg:hl:pis:TP",
>   				    longopts, &optind);
>   		if (c == -1) {
>   			break;
> @@ -402,6 +449,9 @@ static void process_options(int argc, char *argv[])
>   		case 'p':
>   			use_pipes = 1;
>   			break;
> +		case 'i':
> +			use_inet = 1;
> +			break;
>   		case 's':
>   			if ((datasize = atoi(optarg)) <= 0) {
>   				fprintf(stderr, "%s: --datasize|-s requires an integer > 0\n", argv[0]);
> @@ -418,6 +468,11 @@ static void process_options(int argc, char *argv[])
>   			print_usage_exit(1);
>   		}
>   	}
> +
> +	if (use_pipes && use_inet) {
> +		fprintf(stderr, "%s: --pipe|-p and --inet|-i cannot be used together\n", argv[0]);
> +		print_usage_exit(1);
> +	}
>   }
>   
>   void sigcatcher(int sig) {
>