[PATCH v0 0/3] lockperf: a few small improvments

[PATCH v0 0/3] lockperf: a few small improvments

[Daniel Wagner]

From: Daniel Wagner <daniel.wagner@bmw-carit.de>

Hi Jeff,

I had a bunch of small patches in my tree, which I forgot to send.
So here they are...

cheers,
daniel

Daniel Wagner (3):
  Synchronize all clients on start up
  posix03, posix04: Use '-l' instead of '-i' as option argument name
  posix03: Do not kill everything in the process group

 flock01.c | 24 ++++++++++++++++++++++--
 flock02.c | 24 ++++++++++++++++++++++--
 posix01.c | 24 ++++++++++++++++++++++--
 posix02.c | 24 ++++++++++++++++++++++--
 posix03.c | 23 ++++++++++++++++++-----
 posix04.c |  6 +++---
 6 files changed, 109 insertions(+), 16 deletions(-)

-- 
2.5.5

[PATCH v0 1/3] Synchronize all clients on start up

[Daniel Wagner]

From: Daniel Wagner <daniel.wagner@bmw-carit.de>

The child process start working as soon as they are forked. Sometimes
that leads to a workload pattern that no contention happens at all even
with a high number of processes. Since the main motivation of this
this is to benchmark the contention overhead let the clients wait
till all client processes are created.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
---
 flock01.c | 24 ++++++++++++++++++++++--
 flock02.c | 24 ++++++++++++++++++++++--
 posix01.c | 24 ++++++++++++++++++++++--
 posix02.c | 24 ++++++++++++++++++++++--
 4 files changed, 88 insertions(+), 8 deletions(-)

diff --git a/flock01.c b/flock01.c
index f5416f6..5335cd2 100644
--- a/flock01.c
+++ b/flock01.c
@@ -29,6 +29,8 @@
 #define NRPROC (128)
 #define NRLOCK (10240)
 
+#define TFR TEMP_FAILURE_RETRY
+
 static struct timespec *diff;
 
 static int
@@ -84,7 +86,8 @@ usage(char *prog)
 int
 main(int argc, char **argv)
 {
-	int i, opt, valid = 0;
+	int i, c, opt, valid = 0;
+	int to_lockers[2];
 	int nproc = NRPROC;
 	int nlock = NRLOCK;
 	pid_t *pids;
@@ -123,11 +126,28 @@ main(int argc, char **argv)
 		return 1;
 	}
 
+	if (pipe(to_lockers)) {
+		fprintf(stderr, "pipe (to_lockers)");
+		return 1;
+	}
+
 	for (i = 0; i < nproc; ++i) {
 		pids[i] = fork();
-		if (!pids[i])
+		if (!pids[i]) {
+			while (TFR(read(to_lockers[0], &c, 1)) != 1)
+				;
 			return lockunlock(argv[optind], nlock, &diff[i]);
+		}
+	}
+
+	close(to_lockers[0]);
+	for (i = 0; i < nproc; ++i) {
+		if (TFR(write(to_lockers[1], &c, 1)) != 1) {
+			perror("write child");
+			return 1;
+		}
 	}
+	close(to_lockers[1]);
 
 	for (i = 0; i < nproc; ++i) {
 		int status;
diff --git a/flock02.c b/flock02.c
index 81c770a..7c1a470 100644
--- a/flock02.c
+++ b/flock02.c
@@ -30,6 +30,8 @@
 #define NRPROC (128)
 #define NRLOCK (20480)
 
+#define TFR TEMP_FAILURE_RETRY
+
 static struct timespec *diff;
 
 static int
@@ -91,7 +93,8 @@ usage(char *prog)
 int
 main(int argc, char **argv)
 {
-	int i, opt, valid = 0;
+	int i, c, opt, valid = 0;
+	int to_lockers[2];
 	int nproc = NRPROC;
 	int nlock = NRLOCK;
 	pid_t *pids;
@@ -142,11 +145,28 @@ main(int argc, char **argv)
 		return 1;
 	}
 
+	if (pipe(to_lockers)) {
+		fprintf(stderr, "pipe (to_lockers)");
+		return 1;
+	}
+
 	for (i = 0; i < nproc; ++i) {
 		pids[i] = fork();
-		if (!pids[i])
+		if (!pids[i]) {
+			while (TFR(read(to_lockers[0], &c, 1)) != 1)
+				;
 			return lockunlock(nlock, &diff[i]);
+		}
+	}
+
+	close(to_lockers[0]);
+	for (i = 0; i < nproc; ++i) {
+		if (TFR(write(to_lockers[1], &c, 1)) != 1) {
+			perror("write child");
+			return 1;
+		}
 	}
+	close(to_lockers[1]);
 
 	for (i = 0; i < nproc; ++i) {
 		int status;
diff --git a/posix01.c b/posix01.c
index 09f1de6..432a667 100644
--- a/posix01.c
+++ b/posix01.c
@@ -30,6 +30,8 @@
 #define NRPROC (128)
 #define NRLOCK (10240)
 
+#define TFR TEMP_FAILURE_RETRY
+
 static struct timespec *diff;
 
 static int
@@ -97,7 +99,8 @@ int
 main(int argc, char **argv)
 {
 	bool verbose = false, yield = false;
-	int i, opt, valid = 0;
+	int i, c, opt, valid = 0;
+	int to_lockers[2];
 	int nproc = NRPROC;
 	int nlock = NRLOCK;
 	pid_t *pids;
@@ -142,12 +145,29 @@ main(int argc, char **argv)
 		return 1;
 	}
 
+	if (pipe(to_lockers)) {
+		fprintf(stderr, "pipe (to_lockers)");
+		return 1;
+	}
+
 	for (i = 0; i < nproc; ++i) {
 		pids[i] = fork();
-		if (!pids[i])
+		if (!pids[i]) {
+			while (TFR(read(to_lockers[0], &c, 1)) != 1)
+				;
 			return lockunlock(argv[optind], nlock,
 						&diff[i], verbose, yield);
+		}
+	}
+
+	close(to_lockers[0]);
+	for (i = 0; i < nproc; ++i) {
+		if (TFR(write(to_lockers[1], &c, 1)) != 1) {
+			perror("write child");
+			return 1;
+		}
 	}
+	close(to_lockers[1]);
 
 	for (i = 0; i < nproc; ++i) {
 		int status;
diff --git a/posix02.c b/posix02.c
index 9a35c99..5fb2a4d 100644
--- a/posix02.c
+++ b/posix02.c
@@ -29,6 +29,8 @@
 #define NRPROC (128)
 #define NRLOCK (20480)
 
+#define TFR TEMP_FAILURE_RETRY
+
 static struct timespec *diff;
 
 static int
@@ -93,7 +95,8 @@ usage(char *prog)
 int
 main(int argc, char **argv)
 {
-	int i, opt, valid = 0;
+	int i, c, opt, valid = 0;
+	int to_lockers[2];
 	int nproc = NRPROC;
 	int nlock = NRLOCK;
 	pid_t *pids;
@@ -144,11 +147,28 @@ main(int argc, char **argv)
 		return 1;
 	}
 
+	if (pipe(to_lockers)) {
+		fprintf(stderr, "pipe (to_lockers)");
+		return 1;
+	}
+
 	for (i = 0; i < nproc; ++i) {
 		pids[i] = fork();
-		if (!pids[i])
+		if (!pids[i]) {
+			while (TFR(read(to_lockers[0], &c, 1)) != 1)
+				;
 			return lockunlock(nlock, &diff[i]);
+		}
+	}
+
+	close(to_lockers[0]);
+	for (i = 0; i < nproc; ++i) {
+		if (TFR(write(to_lockers[1], &c, 1)) != 1) {
+			perror("write child");
+			return 1;
+		}
 	}
+	close(to_lockers[1]);
 
 	for (i = 0; i < nproc; ++i) {
 		int status;
-- 
2.5.5

[PATCH v0 2/3] posix03, posix04: Use '-l' instead of '-i' as option argument name

[Daniel Wagner]

From: Daniel Wagner <daniel.wagner@bmw-carit.de>

All other test use '=l' instead of '-i' to as option name for defining how many
loops should be executed. Let's streamline posix03 and posix04.

Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
---
 posix03.c | 6 +++---
 posix04.c | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/posix03.c b/posix03.c
index 864f0f0..a36caa5 100644
--- a/posix03.c
+++ b/posix03.c
@@ -109,7 +109,7 @@ static int do_child(int lockfd, int i, int to_lockers, int from_lockers)
 static int
 usage(char *argv0)
 {
-	errx(1, "Usage: %s [-i iterations] [-n nr_children] <filename>", argv0);
+	errx(1, "Usage: %s  [-n nr_procs] [-l nr_loops] <filename>", argv0);
 }
 
 int main(int argc, char *argv[])
@@ -126,9 +126,9 @@ int main(int argc, char *argv[])
 	total.tv_sec = 0;
 	total.tv_nsec = 0;
 
-	while ((opt = getopt(argc, argv, "i:n:")) != -1) {
+	while ((opt = getopt(argc, argv, "l:n:")) != -1) {
 		switch (opt) {
-		case 'i':
+		case 'l':
 			iter = atoi(optarg);
 			break;
 		case 'n':
diff --git a/posix04.c b/posix04.c
index ed862f2..67eb4af 100644
--- a/posix04.c
+++ b/posix04.c
@@ -158,7 +158,7 @@ static int do_child(int fd, int id, int nproc, int to_lockers, int from_lockers)
 static int
 usage(char *argv0)
 {
-	errx(1, "Usage: %s [-i iterations] [-n nr_children] [-s] <filename>", argv0);
+	errx(1, "Usage: %s [-n nr_procs] [-l nr_loops] [-s] <filename>", argv0);
 }
 
 int main(int argc, char *argv[])
@@ -175,9 +175,9 @@ int main(int argc, char *argv[])
 	total.tv_sec = 0;
 	total.tv_nsec = 0;
 
-	while ((opt = getopt(argc, argv, "i:n:s")) != -1) {
+	while ((opt = getopt(argc, argv, "l:n:s")) != -1) {
 		switch (opt) {
-		case 'i':
+		case 'l':
 			iter = atoi(optarg);
 			break;
 		case 'n':
-- 
2.5.5

[PATCH v0 3/3] posix03: Do not kill everything in the process group

[Daniel Wagner]

From: Daniel Wagner <daniel.wagner@bmw-carit.de>

kill(0, SIGINT) sends to all in the process group the signal
including the parent shell.

Instead remember the PIDs of all children and just send the signal
to these processes.

Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
---
 posix03.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/posix03.c b/posix03.c
index a36caa5..4ee130b 100644
--- a/posix03.c
+++ b/posix03.c
@@ -71,13 +71,18 @@ static int fcntl_unlock(int fd, off_t off, off_t len)
 	return fcntl(fd, F_SETLKW, &fl);
 }
 
+/* The PIDs of all children */
+static pid_t *cpids;
+
 static void
 kill_children()
 {
 	siginfo_t	infop;
+	int i;
 
 	signal(SIGINT, SIG_IGN);
-	kill(0, SIGINT);
+	for (i = 0; cpids[i]; i++)
+		kill(cpids[i], SIGINT);
 	while (waitid(P_ALL, 0, &infop, WEXITED) != -1);
 }
 
@@ -161,14 +166,21 @@ int main(int argc, char *argv[])
 
 	signal(SIGINT, sighandler);
 
+	cpids = malloc((num + 1) * sizeof(pid_t));
+	if (!cpids)
+		err(1, "malloc");
+	cpids[num] = 0;
+
 	for (i = 0; i < num; i++) {
-		switch (fork()) {
+		pid_t pid = fork();
+		switch (pid) {
 		case 0:
 			signal(SIGINT, SIG_DFL);
 			return do_child(lockfd, i, to_lockers[0], from_lockers[1]);
 		case -1:
 			err(1, "fork failed");
 		}
+		cpids[i] = pid;
 	}
 
 	close(to_lockers[0]);
@@ -208,5 +220,6 @@ int main(int argc, char *argv[])
 
 	printf("%ld.%09ld\n", total.tv_sec, total.tv_nsec);
 	kill_children();
+	free(cpids);
 	return 0;
 }
-- 
2.5.5