1 files changed, 243 insertions, 41 deletions

diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c
index 69cfba8d4c6c..70139036d68f 100644
--- a/tools/perf/bench/sched-pipe.c
+++ b/tools/perf/bench/sched-pipe.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *
  * sched-pipe.c
@@ -7,33 +8,89 @@
  * Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
  *  http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
  * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
- *
  */
-
-#include "../perf.h"
-#include "../util/util.h"
-#include "../util/parse-options.h"
-#include "../builtin.h"
+#include <subcmd/parse-options.h>
+#include <api/fs/fs.h>
 #include "bench.h"
+#include "util/cgroup.h"
 
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
 #include <sys/wait.h>
-#include <linux/unistd.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>
+#include <linux/time64.h>
+
+#include <pthread.h>
+
+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;
+};
 
 #define LOOPS_DEFAULT 1000000
-static int loops = LOOPS_DEFAULT;
+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_INTEGER('l', "loop", &loops,
-		    "Specify number of loops"),
+	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()
 };
 
@@ -42,78 +99,223 @@ static const char * const bench_sched_pipe_usage[] = {
 	NULL
 };
 
-int bench_sched_pipe(int argc, const char **argv,
-		     const char *prefix __maybe_unused)
+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 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++) {
+		ret = write(td->pipe_write, &m, sizeof(int));
+		BUG_ON(ret != sizeof(int));
+		ret = read_pipe(td);
+		BUG_ON(ret != sizeof(int));
+	}
+
+	return NULL;
+}
+
+int bench_sched_pipe(int argc, const char **argv)
+{
+	struct thread_data threads[2] = {};
+	struct thread_data *td;
 	int pipe_1[2], pipe_2[2];
-	int m = 0, i;
 	struct timeval start, stop, diff;
 	unsigned long long result_usec = 0;
+	int nr_threads = 2;
+	int t;
 
 	/*
 	 * why does "ret" exist?
 	 * 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);
+	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;
 
-	pid = fork();
-	assert(pid >= 0);
+	BUG_ON(pipe2(pipe_1, flags));
+	BUG_ON(pipe2(pipe_2, flags));
 
 	gettimeofday(&start, NULL);
 
-	if (!pid) {
-		for (i = 0; i < loops; i++) {
-			ret = read(pipe_1[0], &m, sizeof(int));
-			ret = write(pipe_2[1], &m, sizeof(int));
+	for (t = 0; t < nr_threads; t++) {
+		td = threads + t;
+
+		td->nr = t;
+
+		if (t == 0) {
+			td->pipe_read = pipe_1[0];
+			td->pipe_write = pipe_2[1];
+		} else {
+			td->pipe_write = pipe_1[1];
+			td->pipe_read = pipe_2[0];
+		}
+	}
+
+	if (threaded) {
+		for (t = 0; t < nr_threads; t++) {
+			td = threads + t;
+
+			ret = pthread_create(&td->pthread, NULL, worker_thread, td);
+			BUG_ON(ret);
+		}
+
+		for (t = 0; t < nr_threads; t++) {
+			td = threads + t;
+
+			ret = pthread_join(td->pthread, NULL);
+			BUG_ON(ret);
 		}
 	} else {
-		for (i = 0; i < loops; i++) {
-			ret = write(pipe_1[1], &m, sizeof(int));
-			ret = read(pipe_2[0], &m, sizeof(int));
+		pid = fork();
+		assert(pid >= 0);
+
+		if (!pid) {
+			worker_thread(threads + 0);
+			exit(0);
+		} else {
+			worker_thread(threads + 1);
 		}
+
+		retpid = waitpid(pid, &wait_stat, 0);
+		assert((retpid == pid) && WIFEXITED(wait_stat));
 	}
 
 	gettimeofday(&stop, NULL);
 	timersub(&stop, &start, &diff);
 
-	if (pid) {
-		retpid = waitpid(pid, &wait_stat, 0);
-		assert((retpid == pid) && WIFEXITED(wait_stat));
-	} else {
-		exit(0);
-	}
+	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 tasks\n\n",
-			loops);
+		printf("# Executed %d pipe operations between two %s\n\n",
+			loops, threaded ? "threads" : "processes");
 
-		result_usec = diff.tv_sec * 1000000;
+		result_usec = diff.tv_sec * USEC_PER_SEC;
 		result_usec += diff.tv_usec;
 
 		printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
-		       diff.tv_sec,
-		       (unsigned long) (diff.tv_usec/1000));
+		       (unsigned long) diff.tv_sec,
+		       (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
 
 		printf(" %14lf usecs/op\n",
 		       (double)result_usec / (double)loops);
 		printf(" %14d ops/sec\n",
 		       (int)((double)loops /
-			     ((double)result_usec / (double)1000000)));
+			     ((double)result_usec / (double)USEC_PER_SEC)));
 		break;
 
 	case BENCH_FORMAT_SIMPLE:
 		printf("%lu.%03lu\n",
-		       diff.tv_sec,
-		       (unsigned long) (diff.tv_usec / 1000));
+		       (unsigned long) diff.tv_sec,
+		       (unsigned long) (diff.tv_usec / USEC_PER_MSEC));
 		break;
 
 	default: