Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1532 insertions, 0 deletions

diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
new file mode 100644
index 000000000..6cb3f6cc3
--- /dev/null
+++ b/tools/perf/builtin-daemon.c
@@ -0,0 +1,1532 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <internal/lib.h>
+#include <subcmd/parse-options.h>
+#include <api/fd/array.h>
+#include <api/fs/fs.h>
+#include <linux/zalloc.h>
+#include <linux/string.h>
+#include <linux/limits.h>
+#include <string.h>
+#include <sys/file.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <time.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/inotify.h>
+#include <libgen.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/stat.h>
+#include <sys/signalfd.h>
+#include <sys/wait.h>
+#include <poll.h>
+#include "builtin.h"
+#include "perf.h"
+#include "debug.h"
+#include "config.h"
+#include "util.h"
+
+#define SESSION_OUTPUT  "output"
+#define SESSION_CONTROL "control"
+#define SESSION_ACK     "ack"
+
+/*
+ * Session states:
+ *
+ *   OK       - session is up and running
+ *   RECONFIG - session is pending for reconfiguration,
+ *              new values are already loaded in session object
+ *   KILL     - session is pending to be killed
+ *
+ * Session object life and its state is maintained by
+ * following functions:
+ *
+ *  setup_server_config
+ *    - reads config file and setup session objects
+ *      with following states:
+ *
+ *      OK       - no change needed
+ *      RECONFIG - session needs to be changed
+ *                 (run variable changed)
+ *      KILL     - session needs to be killed
+ *                 (session is no longer in config file)
+ *
+ *  daemon__reconfig
+ *    - scans session objects and does following actions
+ *      for states:
+ *
+ *      OK       - skip
+ *      RECONFIG - session is killed and re-run with new config
+ *      KILL     - session is killed
+ *
+ *    - all sessions have OK state on the function exit
+ */
+enum daemon_session_state {
+	OK,
+	RECONFIG,
+	KILL,
+};
+
+struct daemon_session {
+	char				*base;
+	char				*name;
+	char				*run;
+	char				*control;
+	int				 pid;
+	struct list_head		 list;
+	enum daemon_session_state	 state;
+	time_t				 start;
+};
+
+struct daemon {
+	const char		*config;
+	char			*config_real;
+	char			*config_base;
+	const char		*csv_sep;
+	const char		*base_user;
+	char			*base;
+	struct list_head	 sessions;
+	FILE			*out;
+	char			 perf[PATH_MAX];
+	int			 signal_fd;
+	time_t			 start;
+};
+
+static struct daemon __daemon = {
+	.sessions = LIST_HEAD_INIT(__daemon.sessions),
+};
+
+static const char * const daemon_usage[] = {
+	"perf daemon start [<options>]",
+	"perf daemon [<options>]",
+	NULL
+};
+
+static bool done;
+
+static void sig_handler(int sig __maybe_unused)
+{
+	done = true;
+}
+
+static struct daemon_session *daemon__add_session(struct daemon *config, char *name)
+{
+	struct daemon_session *session = zalloc(sizeof(*session));
+
+	if (!session)
+		return NULL;
+
+	session->name = strdup(name);
+	if (!session->name) {
+		free(session);
+		return NULL;
+	}
+
+	session->pid = -1;
+	list_add_tail(&session->list, &config->sessions);
+	return session;
+}
+
+static struct daemon_session *daemon__find_session(struct daemon *daemon, char *name)
+{
+	struct daemon_session *session;
+
+	list_for_each_entry(session, &daemon->sessions, list) {
+		if (!strcmp(session->name, name))
+			return session;
+	}
+
+	return NULL;
+}
+
+static int get_session_name(const char *var, char *session, int len)
+{
+	const char *p = var + sizeof("session-") - 1;
+
+	while (*p != '.' && *p != 0x0 && len--)
+		*session++ = *p++;
+
+	*session = 0;
+	return *p == '.' ? 0 : -EINVAL;
+}
+
+static int session_config(struct daemon *daemon, const char *var, const char *value)
+{
+	struct daemon_session *session;
+	char name[100];
+
+	if (get_session_name(var, name, sizeof(name) - 1))
+		return -EINVAL;
+
+	var = strchr(var, '.');
+	if (!var)
+		return -EINVAL;
+
+	var++;
+
+	session = daemon__find_session(daemon, name);
+
+	if (!session) {
+		/* New session is defined. */
+		session = daemon__add_session(daemon, name);
+		if (!session)
+			return -ENOMEM;
+
+		pr_debug("reconfig: found new session %s\n", name);
+
+		/* Trigger reconfig to start it. */
+		session->state = RECONFIG;
+	} else if (session->state == KILL) {
+		/* Current session is defined, no action needed. */
+		pr_debug("reconfig: found current session %s\n", name);
+		session->state = OK;
+	}
+
+	if (!strcmp(var, "run")) {
+		bool same = false;
+
+		if (session->run)
+			same = !strcmp(session->run, value);
+
+		if (!same) {
+			if (session->run) {
+				free(session->run);
+				pr_debug("reconfig: session %s is changed\n", name);
+			}
+
+			session->run = strdup(value);
+			if (!session->run)
+				return -ENOMEM;
+
+			/*
+			 * Either new or changed run value is defined,
+			 * trigger reconfig for the session.
+			 */
+			session->state = RECONFIG;
+		}
+	}
+
+	return 0;
+}
+
+static int server_config(const char *var, const char *value, void *cb)
+{
+	struct daemon *daemon = cb;
+
+	if (strstarts(var, "session-")) {
+		return session_config(daemon, var, value);
+	} else if (!strcmp(var, "daemon.base") && !daemon->base_user) {
+		if (daemon->base && strcmp(daemon->base, value)) {
+			pr_err("failed: can't redefine base, bailing out\n");
+			return -EINVAL;
+		}
+		daemon->base = strdup(value);
+		if (!daemon->base)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int client_config(const char *var, const char *value, void *cb)
+{
+	struct daemon *daemon = cb;
+
+	if (!strcmp(var, "daemon.base") && !daemon->base_user) {
+		daemon->base = strdup(value);
+		if (!daemon->base)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int check_base(struct daemon *daemon)
+{
+	struct stat st;
+
+	if (!daemon->base) {
+		pr_err("failed: base not defined\n");
+		return -EINVAL;
+	}
+
+	if (stat(daemon->base, &st)) {
+		switch (errno) {
+		case EACCES:
+			pr_err("failed: permission denied for '%s' base\n",
+			       daemon->base);
+			return -EACCES;
+		case ENOENT:
+			pr_err("failed: base '%s' does not exists\n",
+			       daemon->base);
+			return -EACCES;
+		default:
+			pr_err("failed: can't access base '%s': %s\n",
+			       daemon->base, strerror(errno));
+			return -errno;
+		}
+	}
+
+	if ((st.st_mode & S_IFMT) != S_IFDIR) {
+		pr_err("failed: base '%s' is not directory\n",
+		       daemon->base);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int setup_client_config(struct daemon *daemon)
+{
+	struct perf_config_set *set = perf_config_set__load_file(daemon->config_real);
+	int err = -ENOMEM;
+
+	if (set) {
+		err = perf_config_set(set, client_config, daemon);
+		perf_config_set__delete(set);
+	}
+
+	return err ?: check_base(daemon);
+}
+
+static int setup_server_config(struct daemon *daemon)
+{
+	struct perf_config_set *set;
+	struct daemon_session *session;
+	int err = -ENOMEM;
+
+	pr_debug("reconfig: started\n");
+
+	/*
+	 * Mark all sessions for kill, the server config
+	 * will set following states, see explanation at
+	 * enum daemon_session_state declaration.
+	 */
+	list_for_each_entry(session, &daemon->sessions, list)
+		session->state = KILL;
+
+	set = perf_config_set__load_file(daemon->config_real);
+	if (set) {
+		err = perf_config_set(set, server_config, daemon);
+		perf_config_set__delete(set);
+	}
+
+	return err ?: check_base(daemon);
+}
+
+static int daemon_session__run(struct daemon_session *session,
+			       struct daemon *daemon)
+{
+	char buf[PATH_MAX];
+	char **argv;
+	int argc, fd;
+
+	if (asprintf(&session->base, "%s/session-%s",
+		     daemon->base, session->name) < 0) {
+		perror("failed: asprintf");
+		return -1;
+	}
+
+	if (mkdir(session->base, 0755) && errno != EEXIST) {
+		perror("failed: mkdir");
+		return -1;
+	}
+
+	session->start = time(NULL);
+
+	session->pid = fork();
+	if (session->pid < 0)
+		return -1;
+	if (session->pid > 0) {
+		pr_info("reconfig: ruining session [%s:%d]: %s\n",
+			session->name, session->pid, session->run);
+		return 0;
+	}
+
+	if (chdir(session->base)) {
+		perror("failed: chdir");
+		return -1;
+	}
+
+	fd = open("/dev/null", O_RDONLY);
+	if (fd < 0) {
+		perror("failed: open /dev/null");
+		return -1;
+	}
+
+	dup2(fd, 0);
+	close(fd);
+
+	fd = open(SESSION_OUTPUT, O_RDWR|O_CREAT|O_TRUNC, 0644);
+	if (fd < 0) {
+		perror("failed: open session output");
+		return -1;
+	}
+
+	dup2(fd, 1);
+	dup2(fd, 2);
+	close(fd);
+
+	if (mkfifo(SESSION_CONTROL, 0600) && errno != EEXIST) {
+		perror("failed: create control fifo");
+		return -1;
+	}
+
+	if (mkfifo(SESSION_ACK, 0600) && errno != EEXIST) {
+		perror("failed: create ack fifo");
+		return -1;
+	}
+
+	scnprintf(buf, sizeof(buf), "%s record --control=fifo:%s,%s %s",
+		  daemon->perf, SESSION_CONTROL, SESSION_ACK, session->run);
+
+	argv = argv_split(buf, &argc);
+	if (!argv)
+		exit(-1);
+
+	exit(execve(daemon->perf, argv, NULL));
+	return -1;
+}
+
+static pid_t handle_signalfd(struct daemon *daemon)
+{
+	struct daemon_session *session;
+	struct signalfd_siginfo si;
+	ssize_t err;
+	int status;
+	pid_t pid;
+
+	/*
+	 * Take signal fd data as pure signal notification and check all
+	 * the sessions state. The reason is that multiple signals can get
+	 * coalesced in kernel and we can receive only single signal even
+	 * if multiple SIGCHLD were generated.
+	 */
+	err = read(daemon->signal_fd, &si, sizeof(struct signalfd_siginfo));
+	if (err != sizeof(struct signalfd_siginfo)) {
+		pr_err("failed to read signal fd\n");
+		return -1;
+	}
+
+	list_for_each_entry(session, &daemon->sessions, list) {
+		if (session->pid == -1)
+			continue;
+
+		pid = waitpid(session->pid, &status, WNOHANG);
+		if (pid <= 0)
+			continue;
+
+		if (WIFEXITED(status)) {
+			pr_info("session '%s' exited, status=%d\n",
+				session->name, WEXITSTATUS(status));
+		} else if (WIFSIGNALED(status)) {
+			pr_info("session '%s' killed (signal %d)\n",
+				session->name, WTERMSIG(status));
+		} else if (WIFSTOPPED(status)) {
+			pr_info("session '%s' stopped (signal %d)\n",
+				session->name, WSTOPSIG(status));
+		} else {
+			pr_info("session '%s' Unexpected status (0x%x)\n",
+				session->name, status);
+		}
+
+		session->state = KILL;
+		session->pid = -1;
+	}
+
+	return 0;
+}
+
+static int daemon_session__wait(struct daemon_session *session, struct daemon *daemon,
+				int secs)
+{
+	struct pollfd pollfd = {
+		.fd	= daemon->signal_fd,
+		.events	= POLLIN,
+	};
+	time_t start;
+
+	start = time(NULL);
+
+	do {
+		int err = poll(&pollfd, 1, 1000);
+
+		if (err > 0) {
+			handle_signalfd(daemon);
+		} else if (err < 0) {
+			perror("failed: poll\n");
+			return -1;
+		}
+
+		if (start + secs < time(NULL))
+			return -1;
+	} while (session->pid != -1);
+
+	return 0;
+}
+
+static bool daemon__has_alive_session(struct daemon *daemon)
+{
+	struct daemon_session *session;
+
+	list_for_each_entry(session, &daemon->sessions, list) {
+		if (session->pid != -1)
+			return true;
+	}
+
+	return false;
+}
+
+static int daemon__wait(struct daemon *daemon, int secs)
+{
+	struct pollfd pollfd = {
+		.fd	= daemon->signal_fd,
+		.events	= POLLIN,
+	};
+	time_t start;
+
+	start = time(NULL);
+
+	do {
+		int err = poll(&pollfd, 1, 1000);
+
+		if (err > 0) {
+			handle_signalfd(daemon);
+		} else if (err < 0) {
+			perror("failed: poll\n");
+			return -1;
+		}
+
+		if (start + secs < time(NULL))
+			return -1;
+	} while (daemon__has_alive_session(daemon));
+
+	return 0;
+}
+
+static int daemon_session__control(struct daemon_session *session,
+				   const char *msg, bool do_ack)
+{
+	struct pollfd pollfd = { .events = POLLIN, };
+	char control_path[PATH_MAX];
+	char ack_path[PATH_MAX];
+	int control, ack = -1, len;
+	char buf[20];
+	int ret = -1;
+	ssize_t err;
+
+	/* open the control file */
+	scnprintf(control_path, sizeof(control_path), "%s/%s",
+		  session->base, SESSION_CONTROL);
+
+	control = open(control_path, O_WRONLY|O_NONBLOCK);
+	if (!control)
+		return -1;
+
+	if (do_ack) {
+		/* open the ack file */
+		scnprintf(ack_path, sizeof(ack_path), "%s/%s",
+			  session->base, SESSION_ACK);
+
+		ack = open(ack_path, O_RDONLY, O_NONBLOCK);
+		if (!ack) {
+			close(control);
+			return -1;
+		}
+	}
+
+	/* write the command */
+	len = strlen(msg);
+
+	err = writen(control, msg, len);
+	if (err != len) {
+		pr_err("failed: write to control pipe: %d (%s)\n",
+		       errno, control_path);
+		goto out;
+	}
+
+	if (!do_ack)
+		goto out;
+
+	/* wait for an ack */
+	pollfd.fd = ack;
+
+	if (!poll(&pollfd, 1, 2000)) {
+		pr_err("failed: control ack timeout\n");
+		goto out;
+	}
+
+	if (!(pollfd.revents & POLLIN)) {
+		pr_err("failed: did not received an ack\n");
+		goto out;
+	}
+
+	err = read(ack, buf, sizeof(buf));
+	if (err > 0)
+		ret = strcmp(buf, "ack\n");
+	else
+		perror("failed: read ack %d\n");
+
+out:
+	if (ack != -1)
+		close(ack);
+
+	close(control);
+	return ret;
+}
+
+static int setup_server_socket(struct daemon *daemon)
+{
+	struct sockaddr_un addr;
+	char path[PATH_MAX];
+	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+
+	if (fd < 0) {
+		fprintf(stderr, "socket: %s\n", strerror(errno));
+		return -1;
+	}
+
+	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
+		perror("failed: fcntl FD_CLOEXEC");
+		close(fd);
+		return -1;
+	}
+
+	scnprintf(path, sizeof(path), "%s/control", daemon->base);
+
+	if (strlen(path) + 1 >= sizeof(addr.sun_path)) {
+		pr_err("failed: control path too long '%s'\n", path);
+		close(fd);
+		return -1;
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+
+	strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
+	unlink(path);
+
+	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+		perror("failed: bind");
+		close(fd);
+		return -1;
+	}
+
+	if (listen(fd, 1) == -1) {
+		perror("failed: listen");
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}
+
+enum {
+	CMD_LIST   = 0,
+	CMD_SIGNAL = 1,
+	CMD_STOP   = 2,
+	CMD_PING   = 3,
+	CMD_MAX,
+};
+
+#define SESSION_MAX 64
+
+union cmd {
+	int cmd;
+
+	/* CMD_LIST */
+	struct {
+		int	cmd;
+		int	verbose;
+		char	csv_sep;
+	} list;
+
+	/* CMD_SIGNAL */
+	struct {
+		int	cmd;
+		int	sig;
+		char	name[SESSION_MAX];
+	} signal;
+
+	/* CMD_PING */
+	struct {
+		int	cmd;
+		char	name[SESSION_MAX];
+	} ping;
+};
+
+enum {
+	PING_OK	  = 0,
+	PING_FAIL = 1,
+	PING_MAX,
+};
+
+static int daemon_session__ping(struct daemon_session *session)
+{
+	return daemon_session__control(session, "ping", true) ?  PING_FAIL : PING_OK;
+}
+
+static int cmd_session_list(struct daemon *daemon, union cmd *cmd, FILE *out)
+{
+	char csv_sep = cmd->list.csv_sep;
+	struct daemon_session *session;
+	time_t curr = time(NULL);
+
+	if (csv_sep) {
+		fprintf(out, "%d%c%s%c%s%c%s/%s",
+			/* pid daemon  */
+			getpid(), csv_sep, "daemon",
+			/* base */
+			csv_sep, daemon->base,
+			/* output */
+			csv_sep, daemon->base, SESSION_OUTPUT);
+
+		fprintf(out, "%c%s/%s",
+			/* lock */
+			csv_sep, daemon->base, "lock");
+
+		fprintf(out, "%c%lu",
+			/* session up time */
+			csv_sep, (curr - daemon->start) / 60);
+
+		fprintf(out, "\n");
+	} else {
+		fprintf(out, "[%d:daemon] base: %s\n", getpid(), daemon->base);
+		if (cmd->list.verbose) {
+			fprintf(out, "  output:  %s/%s\n",
+				daemon->base, SESSION_OUTPUT);
+			fprintf(out, "  lock:    %s/lock\n",
+				daemon->base);
+			fprintf(out, "  up:      %lu minutes\n",
+				(curr - daemon->start) / 60);
+		}
+	}
+
+	list_for_each_entry(session, &daemon->sessions, list) {
+		if (csv_sep) {
+			fprintf(out, "%d%c%s%c%s",
+				/* pid */
+				session->pid,
+				/* name */
+				csv_sep, session->name,
+				/* base */
+				csv_sep, session->run);
+
+			fprintf(out, "%c%s%c%s/%s",
+				/* session dir */
+				csv_sep, session->base,
+				/* session output */
+				csv_sep, session->base, SESSION_OUTPUT);
+
+			fprintf(out, "%c%s/%s%c%s/%s",
+				/* session control */
+				csv_sep, session->base, SESSION_CONTROL,
+				/* session ack */
+				csv_sep, session->base, SESSION_ACK);
+
+			fprintf(out, "%c%lu",
+				/* session up time */
+				csv_sep, (curr - session->start) / 60);
+
+			fprintf(out, "\n");
+		} else {
+			fprintf(out, "[%d:%s] perf record %s\n",
+				session->pid, session->name, session->run);
+			if (!cmd->list.verbose)
+				continue;
+			fprintf(out, "  base:    %s\n",
+				session->base);
+			fprintf(out, "  output:  %s/%s\n",
+				session->base, SESSION_OUTPUT);
+			fprintf(out, "  control: %s/%s\n",
+				session->base, SESSION_CONTROL);
+			fprintf(out, "  ack:     %s/%s\n",
+				session->base, SESSION_ACK);
+			fprintf(out, "  up:      %lu minutes\n",
+				(curr - session->start) / 60);
+		}
+	}
+
+	return 0;
+}
+
+static int daemon_session__signal(struct daemon_session *session, int sig)
+{
+	if (session->pid < 0)
+		return -1;
+	return kill(session->pid, sig);
+}
+
+static int cmd_session_kill(struct daemon *daemon, union cmd *cmd, FILE *out)
+{
+	struct daemon_session *session;
+	bool all = false;
+
+	all = !strcmp(cmd->signal.name, "all");
+
+	list_for_each_entry(session, &daemon->sessions, list) {
+		if (all || !strcmp(cmd->signal.name, session->name)) {
+			daemon_session__signal(session, cmd->signal.sig);
+			fprintf(out, "signal %d sent to session '%s [%d]'\n",
+				cmd->signal.sig, session->name, session->pid);
+		}
+	}
+
+	return 0;
+}
+
+static const char *ping_str[PING_MAX] = {
+	[PING_OK]   = "OK",
+	[PING_FAIL] = "FAIL",
+};
+
+static int cmd_session_ping(struct daemon *daemon, union cmd *cmd, FILE *out)
+{
+	struct daemon_session *session;
+	bool all = false, found = false;
+
+	all = !strcmp(cmd->ping.name, "all");
+
+	list_for_each_entry(session, &daemon->sessions, list) {
+		if (all || !strcmp(cmd->ping.name, session->name)) {
+			int state = daemon_session__ping(session);
+
+			fprintf(out, "%-4s %s\n", ping_str[state], session->name);
+			found = true;
+		}
+	}
+
+	if (!found && !all) {
+		fprintf(out, "%-4s %s (not found)\n",
+			ping_str[PING_FAIL], cmd->ping.name);
+	}
+	return 0;
+}
+
+static int handle_server_socket(struct daemon *daemon, int sock_fd)
+{
+	int ret = -1, fd;
+	FILE *out = NULL;
+	union cmd cmd;
+
+	fd = accept(sock_fd, NULL, NULL);
+	if (fd < 0) {
+		perror("failed: accept");
+		return -1;
+	}
+
+	if (sizeof(cmd) != readn(fd, &cmd, sizeof(cmd))) {
+		perror("failed: read");
+		goto out;
+	}
+
+	out = fdopen(fd, "w");
+	if (!out) {
+		perror("failed: fdopen");
+		goto out;
+	}
+
+	switch (cmd.cmd) {
+	case CMD_LIST:
+		ret = cmd_session_list(daemon, &cmd, out);
+		break;
+	case CMD_SIGNAL:
+		ret = cmd_session_kill(daemon, &cmd, out);
+		break;
+	case CMD_STOP:
+		done = 1;
+		ret = 0;
+		pr_debug("perf daemon is exciting\n");
+		break;
+	case CMD_PING:
+		ret = cmd_session_ping(daemon, &cmd, out);
+		break;
+	default:
+		break;
+	}
+
+	fclose(out);
+out:
+	/* If out is defined, then fd is closed via fclose. */
+	if (!out)
+		close(fd);
+	return ret;
+}
+
+static int setup_client_socket(struct daemon *daemon)
+{
+	struct sockaddr_un addr;
+	char path[PATH_MAX];
+	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+
+	if (fd == -1) {
+		perror("failed: socket");
+		return -1;
+	}
+
+	scnprintf(path, sizeof(path), "%s/control", daemon->base);
+
+	if (strlen(path) + 1 >= sizeof(addr.sun_path)) {
+		pr_err("failed: control path too long '%s'\n", path);
+		close(fd);
+		return -1;
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+	strlcpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
+
+	if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) {
+		perror("failed: connect");
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}
+
+static void daemon_session__kill(struct daemon_session *session,
+				 struct daemon *daemon)
+{
+	int how = 0;
+
+	do {
+		switch (how) {
+		case 0:
+			daemon_session__control(session, "stop", false);
+			break;
+		case 1:
+			daemon_session__signal(session, SIGTERM);
+			break;
+		case 2:
+			daemon_session__signal(session, SIGKILL);
+			break;
+		default:
+			pr_err("failed to wait for session %s\n",
+			       session->name);
+			return;
+		}
+		how++;
+
+	} while (daemon_session__wait(session, daemon, 10));
+}
+
+static void daemon__signal(struct daemon *daemon, int sig)
+{
+	struct daemon_session *session;
+
+	list_for_each_entry(session, &daemon->sessions, list)
+		daemon_session__signal(session, sig);
+}
+
+static void daemon_session__delete(struct daemon_session *session)
+{
+	free(session->base);
+	free(session->name);
+	free(session->run);
+	free(session);
+}
+
+static void daemon_session__remove(struct daemon_session *session)
+{
+	list_del(&session->list);
+	daemon_session__delete(session);
+}
+
+static void daemon__stop(struct daemon *daemon)
+{
+	struct daemon_session *session;
+
+	list_for_each_entry(session, &daemon->sessions, list)
+		daemon_session__control(session, "stop", false);
+}
+
+static void daemon__kill(struct daemon *daemon)
+{
+	int how = 0;
+
+	do {
+		switch (how) {
+		case 0:
+			daemon__stop(daemon);
+			break;
+		case 1:
+			daemon__signal(daemon, SIGTERM);
+			break;
+		case 2:
+			daemon__signal(daemon, SIGKILL);
+			break;
+		default:
+			pr_err("failed to wait for sessions\n");
+			return;
+		}
+		how++;
+
+	} while (daemon__wait(daemon, 10));
+}
+
+static void daemon__exit(struct daemon *daemon)
+{
+	struct daemon_session *session, *h;
+
+	list_for_each_entry_safe(session, h, &daemon->sessions, list)
+		daemon_session__remove(session);
+
+	free(daemon->config_real);
+	free(daemon->config_base);
+	free(daemon->base);
+}
+
+static int daemon__reconfig(struct daemon *daemon)
+{
+	struct daemon_session *session, *n;
+
+	list_for_each_entry_safe(session, n, &daemon->sessions, list) {
+		/* No change. */
+		if (session->state == OK)
+			continue;
+
+		/* Remove session. */
+		if (session->state == KILL) {
+			if (session->pid > 0) {
+				daemon_session__kill(session, daemon);
+				pr_info("reconfig: session '%s' killed\n", session->name);
+			}
+			daemon_session__remove(session);
+			continue;
+		}
+
+		/* Reconfig session. */
+		if (session->pid > 0) {
+			daemon_session__kill(session, daemon);
+			pr_info("reconfig: session '%s' killed\n", session->name);
+		}
+		if (daemon_session__run(session, daemon))
+			return -1;
+
+		session->state = OK;
+	}
+
+	return 0;
+}
+
+static int setup_config_changes(struct daemon *daemon)
+{
+	char *basen = strdup(daemon->config_real);
+	char *dirn  = strdup(daemon->config_real);
+	char *base, *dir;
+	int fd, wd = -1;
+
+	if (!dirn || !basen)
+		goto out;
+
+	fd = inotify_init1(IN_NONBLOCK|O_CLOEXEC);
+	if (fd < 0) {
+		perror("failed: inotify_init");
+		goto out;
+	}
+
+	dir = dirname(dirn);
+	base = basename(basen);
+	pr_debug("config file: %s, dir: %s\n", base, dir);
+
+	wd = inotify_add_watch(fd, dir, IN_CLOSE_WRITE);
+	if (wd >= 0) {
+		daemon->config_base = strdup(base);
+		if (!daemon->config_base) {
+			close(fd);
+			wd = -1;
+		}
+	} else {
+		perror("failed: inotify_add_watch");
+	}
+
+out:
+	free(basen);
+	free(dirn);
+	return wd < 0 ? -1 : fd;
+}
+
+static bool process_inotify_event(struct daemon *daemon, char *buf, ssize_t len)
+{
+	char *p = buf;
+
+	while (p < (buf + len)) {
+		struct inotify_event *event = (struct inotify_event *) p;
+
+		/*
+		 * We monitor config directory, check if our
+		 * config file was changes.
+		 */
+		if ((event->mask & IN_CLOSE_WRITE) &&
+		    !(event->mask & IN_ISDIR)) {
+			if (!strcmp(event->name, daemon->config_base))
+				return true;
+		}
+		p += sizeof(*event) + event->len;
+	}
+	return false;
+}
+
+static int handle_config_changes(struct daemon *daemon, int conf_fd,
+				 bool *config_changed)
+{
+	char buf[4096];
+	ssize_t len;
+
+	while (!(*config_changed)) {
+		len = read(conf_fd, buf, sizeof(buf));
+		if (len == -1) {
+			if (errno != EAGAIN) {
+				perror("failed: read");
+				return -1;
+			}
+			return 0;
+		}
+		*config_changed = process_inotify_event(daemon, buf, len);
+	}
+	return 0;
+}
+
+static int setup_config(struct daemon *daemon)
+{
+	if (daemon->base_user) {
+		daemon->base = strdup(daemon->base_user);
+		if (!daemon->base)
+			return -ENOMEM;
+	}
+
+	if (daemon->config) {
+		char *real = realpath(daemon->config, NULL);
+
+		if (!real) {
+			perror("failed: realpath");
+			return -1;
+		}
+		daemon->config_real = real;
+		return 0;
+	}
+
+	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK))
+		daemon->config_real = strdup(perf_etc_perfconfig());
+	else if (perf_config_global() && perf_home_perfconfig())
+		daemon->config_real = strdup(perf_home_perfconfig());
+
+	return daemon->config_real ? 0 : -1;
+}
+
+#ifndef F_TLOCK
+#define F_TLOCK 2
+
+static int lockf(int fd, int cmd, off_t len)
+{
+	if (cmd != F_TLOCK || len != 0)
+		return -1;
+
+	return flock(fd, LOCK_EX | LOCK_NB);
+}
+#endif // F_TLOCK
+
+/*
+ * Each daemon tries to create and lock BASE/lock file,
+ * if it's successful we are sure we're the only daemon
+ * running over the BASE.
+ *
+ * Once daemon is finished, file descriptor to lock file
+ * is closed and lock is released.
+ */
+static int check_lock(struct daemon *daemon)
+{
+	char path[PATH_MAX];
+	char buf[20];
+	int fd, pid;
+	ssize_t len;
+
+	scnprintf(path, sizeof(path), "%s/lock", daemon->base);
+
+	fd = open(path, O_RDWR|O_CREAT|O_CLOEXEC, 0640);
+	if (fd < 0)
+		return -1;
+
+	if (lockf(fd, F_TLOCK, 0) < 0) {
+		filename__read_int(path, &pid);
+		fprintf(stderr, "failed: another perf daemon (pid %d) owns %s\n",
+			pid, daemon->base);
+		close(fd);
+		return -1;
+	}
+
+	scnprintf(buf, sizeof(buf), "%d", getpid());
+	len = strlen(buf);
+
+	if (write(fd, buf, len) != len) {
+		perror("failed: write");
+		close(fd);
+		return -1;
+	}
+
+	if (ftruncate(fd, len)) {
+		perror("failed: ftruncate");
+		close(fd);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int go_background(struct daemon *daemon)
+{
+	int pid, fd;
+
+	pid = fork();
+	if (pid < 0)
+		return -1;
+
+	if (pid > 0)
+		return 1;
+
+	if (setsid() < 0)
+		return -1;
+
+	if (check_lock(daemon))
+		return -1;
+
+	umask(0);
+
+	if (chdir(daemon->base)) {
+		perror("failed: chdir");
+		return -1;
+	}
+
+	fd = open("output", O_RDWR|O_CREAT|O_TRUNC, 0644);
+	if (fd < 0) {
+		perror("failed: open");
+		return -1;
+	}
+
+	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
+		perror("failed: fcntl FD_CLOEXEC");
+		close(fd);
+		return -1;
+	}
+
+	close(0);
+	dup2(fd, 1);
+	dup2(fd, 2);
+	close(fd);
+
+	daemon->out = fdopen(1, "w");
+	if (!daemon->out) {
+		close(1);
+		close(2);
+		return -1;
+	}
+
+	setbuf(daemon->out, NULL);
+	return 0;
+}
+
+static int setup_signalfd(struct daemon *daemon)
+{
+	sigset_t mask;
+
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGCHLD);
+
+	if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
+		return -1;
+
+	daemon->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
+	return daemon->signal_fd;
+}
+
+static int __cmd_start(struct daemon *daemon, struct option parent_options[],
+		       int argc, const char **argv)
+{
+	bool foreground = false;
+	struct option start_options[] = {
+		OPT_BOOLEAN('f', "foreground", &foreground, "stay on console"),
+		OPT_PARENT(parent_options),
+		OPT_END()
+	};
+	int sock_fd = -1, conf_fd = -1, signal_fd = -1;
+	int sock_pos, file_pos, signal_pos;
+	struct fdarray fda;
+	int err = 0;
+
+	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
+	if (argc)
+		usage_with_options(daemon_usage, start_options);
+
+	daemon->start = time(NULL);
+
+	if (setup_config(daemon)) {
+		pr_err("failed: config not found\n");
+		return -1;
+	}
+
+	if (setup_server_config(daemon))
+		return -1;
+
+	if (foreground && check_lock(daemon))
+		return -1;
+
+	if (!foreground) {
+		err = go_background(daemon);
+		if (err) {
+			/* original process, exit normally */
+			if (err == 1)
+				err = 0;
+			daemon__exit(daemon);
+			return err;
+		}
+	}
+
+	debug_set_file(daemon->out);
+	debug_set_display_time(true);
+
+	pr_info("daemon started (pid %d)\n", getpid());
+
+	fdarray__init(&fda, 3);
+
+	sock_fd = setup_server_socket(daemon);
+	if (sock_fd < 0)
+		goto out;
+
+	conf_fd = setup_config_changes(daemon);
+	if (conf_fd < 0)
+		goto out;
+
+	signal_fd = setup_signalfd(daemon);
+	if (signal_fd < 0)
+		goto out;
+
+	sock_pos = fdarray__add(&fda, sock_fd, POLLIN|POLLERR|POLLHUP, 0);
+	if (sock_pos < 0)
+		goto out;
+
+	file_pos = fdarray__add(&fda, conf_fd, POLLIN|POLLERR|POLLHUP, 0);
+	if (file_pos < 0)
+		goto out;
+
+	signal_pos = fdarray__add(&fda, signal_fd, POLLIN|POLLERR|POLLHUP, 0);
+	if (signal_pos < 0)
+		goto out;
+
+	signal(SIGINT, sig_handler);
+	signal(SIGTERM, sig_handler);
+	signal(SIGPIPE, SIG_IGN);
+
+	while (!done && !err) {
+		err = daemon__reconfig(daemon);
+
+		if (!err && fdarray__poll(&fda, -1)) {
+			bool reconfig = false;
+
+			if (fda.entries[sock_pos].revents & POLLIN)
+				err = handle_server_socket(daemon, sock_fd);
+			if (fda.entries[file_pos].revents & POLLIN)
+				err = handle_config_changes(daemon, conf_fd, &reconfig);
+			if (fda.entries[signal_pos].revents & POLLIN)
+				err = handle_signalfd(daemon) < 0;
+
+			if (reconfig)
+				err = setup_server_config(daemon);
+		}
+	}
+
+out:
+	fdarray__exit(&fda);
+
+	daemon__kill(daemon);
+	daemon__exit(daemon);
+
+	if (sock_fd != -1)
+		close(sock_fd);
+	if (conf_fd != -1)
+		close(conf_fd);
+	if (signal_fd != -1)
+		close(signal_fd);
+
+	pr_info("daemon exited\n");
+	fclose(daemon->out);
+	return err;
+}
+
+static int send_cmd(struct daemon *daemon, union cmd *cmd)
+{
+	int ret = -1, fd;
+	char *line = NULL;
+	size_t len = 0;
+	ssize_t nread;
+	FILE *in = NULL;
+
+	if (setup_client_config(daemon))
+		return -1;
+
+	fd = setup_client_socket(daemon);
+	if (fd < 0)
+		return -1;
+
+	if (sizeof(*cmd) != writen(fd, cmd, sizeof(*cmd))) {
+		perror("failed: write");
+		goto out;
+	}
+
+	in = fdopen(fd, "r");
+	if (!in) {
+		perror("failed: fdopen");
+		goto out;
+	}
+
+	while ((nread = getline(&line, &len, in)) != -1) {
+		if (fwrite(line, nread, 1, stdout) != 1)
+			goto out_fclose;
+		fflush(stdout);
+	}
+
+	ret = 0;
+out_fclose:
+	fclose(in);
+	free(line);
+out:
+	/* If in is defined, then fd is closed via fclose. */
+	if (!in)
+		close(fd);
+	return ret;
+}
+
+static int send_cmd_list(struct daemon *daemon)
+{
+	union cmd cmd;
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.list.cmd = CMD_LIST;
+	cmd.list.verbose = verbose;
+	cmd.list.csv_sep = daemon->csv_sep ? *daemon->csv_sep : 0;
+
+	return send_cmd(daemon, &cmd);
+}
+
+static int __cmd_signal(struct daemon *daemon, struct option parent_options[],
+			int argc, const char **argv)
+{
+	const char *name = "all";
+	struct option start_options[] = {
+		OPT_STRING(0, "session", &name, "session",
+			"Sent signal to specific session"),
+		OPT_PARENT(parent_options),
+		OPT_END()
+	};
+	union cmd cmd;
+
+	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
+	if (argc)
+		usage_with_options(daemon_usage, start_options);
+
+	if (setup_config(daemon)) {
+		pr_err("failed: config not found\n");
+		return -1;
+	}
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.signal.cmd = CMD_SIGNAL,
+	cmd.signal.sig = SIGUSR2;
+	strncpy(cmd.signal.name, name, sizeof(cmd.signal.name) - 1);
+
+	return send_cmd(daemon, &cmd);
+}
+
+static int __cmd_stop(struct daemon *daemon, struct option parent_options[],
+			int argc, const char **argv)
+{
+	struct option start_options[] = {
+		OPT_PARENT(parent_options),
+		OPT_END()
+	};
+	union cmd cmd;
+
+	argc = parse_options(argc, argv, start_options, daemon_usage, 0);
+	if (argc)
+		usage_with_options(daemon_usage, start_options);
+
+	if (setup_config(daemon)) {
+		pr_err("failed: config not found\n");
+		return -1;
+	}
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.cmd = CMD_STOP;
+	return send_cmd(daemon, &cmd);
+}
+
+static int __cmd_ping(struct daemon *daemon, struct option parent_options[],
+		      int argc, const char **argv)
+{
+	const char *name = "all";
+	struct option ping_options[] = {
+		OPT_STRING(0, "session", &name, "session",
+			"Ping to specific session"),
+		OPT_PARENT(parent_options),
+		OPT_END()
+	};
+	union cmd cmd;
+
+	argc = parse_options(argc, argv, ping_options, daemon_usage, 0);
+	if (argc)
+		usage_with_options(daemon_usage, ping_options);
+
+	if (setup_config(daemon)) {
+		pr_err("failed: config not found\n");
+		return -1;
+	}
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.cmd = CMD_PING;
+	scnprintf(cmd.ping.name, sizeof(cmd.ping.name), "%s", name);
+	return send_cmd(daemon, &cmd);
+}
+
+int cmd_daemon(int argc, const char **argv)
+{
+	struct option daemon_options[] = {
+		OPT_INCR('v', "verbose", &verbose, "be more verbose"),
+		OPT_STRING(0, "config", &__daemon.config,
+			"config file", "config file path"),
+		OPT_STRING(0, "base", &__daemon.base_user,
+			"directory", "base directory"),
+		OPT_STRING_OPTARG('x', "field-separator", &__daemon.csv_sep,
+			"field separator", "print counts with custom separator", ","),
+		OPT_END()
+	};
+
+	perf_exe(__daemon.perf, sizeof(__daemon.perf));
+	__daemon.out = stdout;
+
+	argc = parse_options(argc, argv, daemon_options, daemon_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	if (argc) {
+		if (!strcmp(argv[0], "start"))
+			return __cmd_start(&__daemon, daemon_options, argc, argv);
+		if (!strcmp(argv[0], "signal"))
+			return __cmd_signal(&__daemon, daemon_options, argc, argv);
+		else if (!strcmp(argv[0], "stop"))
+			return __cmd_stop(&__daemon, daemon_options, argc, argv);
+		else if (!strcmp(argv[0], "ping"))
+			return __cmd_ping(&__daemon, daemon_options, argc, argv);
+
+		pr_err("failed: unknown command '%s'\n", argv[0]);
+		return -1;
+	}
+
+	if (setup_config(&__daemon)) {
+		pr_err("failed: config not found\n");
+		return -1;
+	}
+
+	return send_cmd_list(&__daemon);
+}