1 files changed, 168 insertions, 22 deletions

diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c
index 3c88d1f201f1..70139036d68f 100644
--- a/tools/perf/bench/sched-pipe.c
+++ b/tools/perf/bench/sched-pipe.c
@@ -10,7 +10,9 @@
  * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
  */
 #include <subcmd/parse-options.h>
+#include <api/fs/fs.h>
 #include "bench.h"
+#include "util/cgroup.h"
 
 #include <unistd.h>
 #include <stdio.h>
@@ -19,7 +21,9 @@
 #include <sys/wait.h>
 #include <string.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <assert.h>
+#include <sys/epoll.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/syscall.h>
@@ -31,6 +35,9 @@ struct thread_data {
 	int			nr;
 	int			pipe_read;
 	int			pipe_write;
+	struct epoll_event      epoll_ev;
+	int			epoll_fd;
+	bool			cgroup_failed;
 	pthread_t		pthread;
 };
 
@@ -40,9 +47,50 @@ static	int			loops = LOOPS_DEFAULT;
 /* Use processes by default: */
 static bool			threaded;
 
+static bool			nonblocking;
+static char			*cgrp_names[2];
+static struct cgroup		*cgrps[2];
+
+static int parse_two_cgroups(const struct option *opt __maybe_unused,
+			     const char *str, int unset __maybe_unused)
+{
+	char *p = strdup(str);
+	char *q;
+	int ret = -1;
+
+	if (p == NULL) {
+		fprintf(stderr, "memory allocation failure\n");
+		return -1;
+	}
+
+	q = strchr(p, ',');
+	if (q == NULL) {
+		fprintf(stderr, "it should have two cgroup names: %s\n", p);
+		goto out;
+	}
+	*q = '\0';
+
+	cgrp_names[0] = strdup(p);
+	cgrp_names[1] = strdup(q + 1);
+
+	if (cgrp_names[0] == NULL || cgrp_names[1] == NULL) {
+		fprintf(stderr, "memory allocation failure\n");
+		goto out;
+	}
+	ret = 0;
+
+out:
+	free(p);
+	return ret;
+}
+
 static const struct option options[] = {
+	OPT_BOOLEAN('n', "nonblocking",	&nonblocking,	"Use non-blocking operations"),
 	OPT_INTEGER('l', "loop",	&loops,		"Specify number of loops"),
 	OPT_BOOLEAN('T', "threaded",	&threaded,	"Specify threads/process based task setup"),
+	OPT_CALLBACK('G', "cgroups", NULL, "SEND,RECV",
+		     "Put sender and receivers in given cgroups",
+		     parse_two_cgroups),
 	OPT_END()
 };
 
@@ -51,24 +99,115 @@ static const char * const bench_sched_pipe_usage[] = {
 	NULL
 };
 
+static int enter_cgroup(int nr)
+{
+	char buf[32];
+	int fd, len, ret;
+	int saved_errno;
+	struct cgroup *cgrp;
+	pid_t pid;
+
+	if (cgrp_names[nr] == NULL)
+		return 0;
+
+	if (cgrps[nr] == NULL) {
+		cgrps[nr] = cgroup__new(cgrp_names[nr], /*do_open=*/true);
+		if (cgrps[nr] == NULL)
+			goto err;
+	}
+	cgrp = cgrps[nr];
+
+	if (threaded)
+		pid = syscall(__NR_gettid);
+	else
+		pid = getpid();
+
+	snprintf(buf, sizeof(buf), "%d\n", pid);
+	len = strlen(buf);
+
+	/* try cgroup v2 interface first */
+	if (threaded)
+		fd = openat(cgrp->fd, "cgroup.threads", O_WRONLY);
+	else
+		fd = openat(cgrp->fd, "cgroup.procs", O_WRONLY);
+
+	/* try cgroup v1 if failed */
+	if (fd < 0 && errno == ENOENT)
+		fd = openat(cgrp->fd, "tasks", O_WRONLY);
+
+	if (fd < 0)
+		goto err;
+
+	ret = write(fd, buf, len);
+	close(fd);
+
+	if (ret != len) {
+		printf("Cannot enter to cgroup: %s\n", cgrp->name);
+		return -1;
+	}
+	return 0;
+
+err:
+	saved_errno = errno;
+	printf("Failed to open cgroup file in %s\n", cgrp_names[nr]);
+
+	if (saved_errno == ENOENT) {
+		char mnt[PATH_MAX];
+
+		if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event") == 0)
+			printf(" Hint: create the cgroup first, like 'mkdir %s/%s'\n",
+			       mnt, cgrp_names[nr]);
+	} else if (saved_errno == EACCES && geteuid() > 0) {
+		printf(" Hint: try to run as root\n");
+	}
+
+	return -1;
+}
+
+static void exit_cgroup(int nr)
+{
+	cgroup__put(cgrps[nr]);
+	free(cgrp_names[nr]);
+}
+
+static inline int read_pipe(struct thread_data *td)
+{
+	int ret, m;
+retry:
+	if (nonblocking) {
+		ret = epoll_wait(td->epoll_fd, &td->epoll_ev, 1, -1);
+		if (ret < 0)
+			return ret;
+	}
+	ret = read(td->pipe_read, &m, sizeof(int));
+	if (nonblocking && ret < 0 && errno == EWOULDBLOCK)
+		goto retry;
+	return ret;
+}
+
 static void *worker_thread(void *__tdata)
 {
 	struct thread_data *td = __tdata;
-	int m = 0, i;
-	int ret;
+	int i, ret, m = 0;
+
+	ret = enter_cgroup(td->nr);
+	if (ret < 0) {
+		td->cgroup_failed = true;
+		return NULL;
+	}
+
+	if (nonblocking) {
+		td->epoll_ev.events = EPOLLIN;
+		td->epoll_fd = epoll_create(1);
+		BUG_ON(td->epoll_fd < 0);
+		BUG_ON(epoll_ctl(td->epoll_fd, EPOLL_CTL_ADD, td->pipe_read, &td->epoll_ev) < 0);
+	}
 
 	for (i = 0; i < loops; i++) {
-		if (!td->nr) {
-			ret = read(td->pipe_read, &m, sizeof(int));
-			BUG_ON(ret != sizeof(int));
-			ret = write(td->pipe_write, &m, sizeof(int));
-			BUG_ON(ret != sizeof(int));
-		} else {
-			ret = write(td->pipe_write, &m, sizeof(int));
-			BUG_ON(ret != sizeof(int));
-			ret = read(td->pipe_read, &m, sizeof(int));
-			BUG_ON(ret != sizeof(int));
-		}
+		ret = write(td->pipe_write, &m, sizeof(int));
+		BUG_ON(ret != sizeof(int));
+		ret = read_pipe(td);
+		BUG_ON(ret != sizeof(int));
 	}
 
 	return NULL;
@@ -76,7 +215,8 @@ static void *worker_thread(void *__tdata)
 
 int bench_sched_pipe(int argc, const char **argv)
 {
-	struct thread_data threads[2], *td;
+	struct thread_data threads[2] = {};
+	struct thread_data *td;
 	int pipe_1[2], pipe_2[2];
 	struct timeval start, stop, diff;
 	unsigned long long result_usec = 0;
@@ -88,13 +228,16 @@ int bench_sched_pipe(int argc, const char **argv)
 	 * discarding returned value of read(), write()
 	 * causes error in building environment for perf
 	 */
-	int __maybe_unused ret, wait_stat;
+	int __maybe_unused ret, wait_stat, flags = 0;
 	pid_t pid, retpid __maybe_unused;
 
 	argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0);
 
-	BUG_ON(pipe(pipe_1));
-	BUG_ON(pipe(pipe_2));
+	if (nonblocking)
+		flags |= O_NONBLOCK;
+
+	BUG_ON(pipe2(pipe_1, flags));
+	BUG_ON(pipe2(pipe_2, flags));
 
 	gettimeofday(&start, NULL);
 
@@ -112,9 +255,7 @@ int bench_sched_pipe(int argc, const char **argv)
 		}
 	}
 
-
 	if (threaded) {
-
 		for (t = 0; t < nr_threads; t++) {
 			td = threads + t;
 
@@ -128,7 +269,6 @@ int bench_sched_pipe(int argc, const char **argv)
 			ret = pthread_join(td->pthread, NULL);
 			BUG_ON(ret);
 		}
-
 	} else {
 		pid = fork();
 		assert(pid >= 0);
@@ -147,6 +287,12 @@ int bench_sched_pipe(int argc, const char **argv)
 	gettimeofday(&stop, NULL);
 	timersub(&stop, &start, &diff);
 
+	exit_cgroup(0);
+	exit_cgroup(1);
+
+	if (threads[0].cgroup_failed || threads[1].cgroup_failed)
+		return 0;
+
 	switch (bench_format) {
 	case BENCH_FORMAT_DEFAULT:
 		printf("# Executed %d pipe operations between two %s\n\n",
@@ -156,7 +302,7 @@ int bench_sched_pipe(int argc, const char **argv)
 		result_usec += diff.tv_usec;
 
 		printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
-		       diff.tv_sec,
+		       (unsigned long) diff.tv_sec,
 		       (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
 
 		printf(" %14lf usecs/op\n",
@@ -168,7 +314,7 @@ int bench_sched_pipe(int argc, const char **argv)
 
 	case BENCH_FORMAT_SIMPLE:
 		printf("%lu.%03lu\n",
-		       diff.tv_sec,
+		       (unsigned long) diff.tv_sec,
 		       (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
 		break;