Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 08/22] perf daemon: Add config file change check | Date | Sat, 2 Jan 2021 23:04:27 +0100 |
| |
Adding support to detect daemon's config file changes and re-read the configuration when that happens.
Using inotify file descriptor pluged into the main fdarray object for polling.
Example:
# cat ~/.perfconfig [daemon] base=/opt/perfdata
[session-cycles] run = -m 10M -e cycles --overwrite --switch-output -a
Starting the daemon:
# perf daemon start
Check sessions:
# perf daemon [772262:daemon] base: /opt/perfdata [772263:cycles] perf record -m 10M -e cycles --overwrite --switch-output -a
Change '-m 10M' to '-m 20M', and check daemon log:
# tail -f /opt/perfdata/output [2021-01-02 20:31:41.234045] daemon started (pid 772262) [2021-01-02 20:31:41.235072] reconfig: ruining session [cycles:772263]: -m 10M -e cycles --overwrite --switch-output -a [2021-01-02 20:32:08.310137] reconfig: session 'cycles' killed [2021-01-02 20:32:08.310847] reconfig: ruining session [cycles:772338]: -m 20M -e cycles --overwrite --switch-output -a
And the session list:
# perf daemon [772262:daemon] base: /opt/perfdata [772338:cycles] perf record -m 20M -e cycles --overwrite --switch-output -a
Note the changed '-m 20M' option is in place.
Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- tools/perf/builtin-daemon.c | 84 ++++++++++++++++++++++++++++++++++++- 1 file changed, 83 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c index c2a7738a6a4a..16b24c30722d 100644 --- a/tools/perf/builtin-daemon.c +++ b/tools/perf/builtin-daemon.c @@ -547,6 +547,77 @@ static int setup_client_socket(struct daemon *daemon) return fd; } +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; + + if (!dirn || !basen) + return -ENOMEM; + + fd = inotify_init1(IN_NONBLOCK|O_CLOEXEC); + if (fd < 0) { + perror("inotify_init failed"); + return -1; + } + + 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) + perror("inotify_add_watch failed"); + else + daemon->config_base = base; + + 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("read failed"); + return -1; + } + return 0; + } + *config_changed = process_inotify_event(daemon, buf, len); + } + return 0; +} + static int go_background(struct daemon *daemon) { int pid, fd; @@ -617,7 +688,7 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], OPT_PARENT(parent_options), OPT_END() }; - int sock_pos, sock_fd; + int sock_pos, file_pos, sock_fd, conf_fd; struct fdarray fda; int err = 0; @@ -645,6 +716,10 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], if (sock_fd < 0) return -1; + conf_fd = setup_config_changes(daemon); + if (conf_fd < 0) + return -1; + /* socket, inotify */ fdarray__init(&fda, 2); @@ -652,6 +727,10 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], if (sock_pos < 0) return -1; + file_pos = fdarray__add(&fda, conf_fd, POLLIN|POLLERR|POLLHUP, 0); + if (file_pos < 0) + return -1; + signal(SIGINT, sig_handler); signal(SIGTERM, sig_handler); @@ -663,6 +742,8 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], 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 (reconfig) err = setup_server_config(daemon); @@ -673,6 +754,7 @@ static int __cmd_start(struct daemon *daemon, struct option parent_options[], daemon__exit(daemon); close(sock_fd); + close(conf_fd); return err; } -- 2.26.2
| |