diff options
Diffstat (limited to 'tools/perf/builtin-record.c')
| -rw-r--r-- | tools/perf/builtin-record.c | 141 |
1 files changed, 93 insertions, 48 deletions
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 4decbd14eae..63136d0534d 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -123,7 +123,8 @@ static void write_event(event_t *buf, size_t size) write_output(buf, size); } -static int process_synthesized_event(event_t *event) +static int process_synthesized_event(event_t *event, + struct perf_session *self __used) { write_event(event, event->header.size); return 0; @@ -277,7 +278,7 @@ static void create_counter(int counter, int cpu, pid_t pid) attr->mmap = track; attr->comm = track; - attr->inherit = (cpu < 0) && inherit; + attr->inherit = inherit; attr->disabled = 1; try_again: @@ -401,7 +402,7 @@ static void atexit_header(void) perf_header__write(&session->header, output, true); } -static int __cmd_record(int argc, const char **argv) +static int __cmd_record(int argc __used, const char **argv) { int i, counter; struct stat st; @@ -409,6 +410,8 @@ static int __cmd_record(int argc, const char **argv) int flags; int err; unsigned long waking = 0; + int child_ready_pipe[2], go_pipe[2]; + char buf; page_size = sysconf(_SC_PAGE_SIZE); nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); @@ -419,11 +422,25 @@ static int __cmd_record(int argc, const char **argv) signal(SIGCHLD, sig_handler); signal(SIGINT, sig_handler); + if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) { + perror("failed to create pipes"); + exit(-1); + } + if (!stat(output_name, &st) && st.st_size) { - if (!force && !append_file) { - fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n", - output_name); - exit(-1); + if (!force) { + if (!append_file) { + pr_err("Error, output file %s exists, use -A " + "to append or -f to overwrite.\n", + output_name); + exit(-1); + } + } else { + char oldname[PATH_MAX]; + snprintf(oldname, sizeof(oldname), "%s.old", + output_name); + unlink(oldname); + rename(output_name, oldname); } } else { append_file = 0; @@ -466,19 +483,65 @@ static int __cmd_record(int argc, const char **argv) atexit(atexit_header); - if (!system_wide) { - pid = target_pid; - if (pid == -1) - pid = getpid(); + if (target_pid == -1) { + pid = fork(); + if (pid < 0) { + perror("failed to fork"); + exit(-1); + } - open_counters(profile_cpu, pid); - } else { - if (profile_cpu != -1) { - open_counters(profile_cpu, target_pid); - } else { - for (i = 0; i < nr_cpus; i++) - open_counters(i, target_pid); + if (!pid) { + close(child_ready_pipe[0]); + close(go_pipe[1]); + fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC); + + /* + * Do a dummy execvp to get the PLT entry resolved, + * so we avoid the resolver overhead on the real + * execvp call. + */ + execvp("", (char **)argv); + + /* + * Tell the parent we're ready to go + */ + close(child_ready_pipe[1]); + + /* + * Wait until the parent tells us to go. + */ + if (read(go_pipe[0], &buf, 1) == -1) + perror("unable to read pipe"); + + execvp(argv[0], (char **)argv); + + perror(argv[0]); + exit(-1); } + + child_pid = pid; + + if (!system_wide) + target_pid = pid; + + close(child_ready_pipe[1]); + close(go_pipe[0]); + /* + * wait for child to settle + */ + if (read(child_ready_pipe[0], &buf, 1) == -1) { + perror("unable to read pipe"); + exit(-1); + } + close(child_ready_pipe[0]); + } + + + if ((!system_wide && !inherit) || profile_cpu != -1) { + open_counters(profile_cpu, target_pid); + } else { + for (i = 0; i < nr_cpus; i++) + open_counters(i, target_pid); } if (file_new) { @@ -488,33 +551,10 @@ static int __cmd_record(int argc, const char **argv) } if (!system_wide) - event__synthesize_thread(pid, process_synthesized_event); + event__synthesize_thread(pid, process_synthesized_event, + session); else - event__synthesize_threads(process_synthesized_event); - - if (target_pid == -1 && argc) { - pid = fork(); - if (pid < 0) - die("failed to fork"); - - if (!pid) { - if (execvp(argv[0], (char **)argv)) { - perror(argv[0]); - exit(-1); - } - } else { - /* - * Wait a bit for the execv'ed child to appear - * and be updated in /proc - * FIXME: Do you know a less heuristical solution? - */ - usleep(1000); - event__synthesize_thread(pid, - process_synthesized_event); - } - - child_pid = pid; - } + event__synthesize_threads(process_synthesized_event, session); if (realtime_prio) { struct sched_param param; @@ -526,6 +566,11 @@ static int __cmd_record(int argc, const char **argv) } } + /* + * Let the child rip + */ + close(go_pipe[1]); + for (;;) { int hits = samples; @@ -620,13 +665,13 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) { int counter; - symbol__init(0); - argc = parse_options(argc, argv, options, record_usage, - PARSE_OPT_STOP_AT_NON_OPTION); - if (!argc && target_pid == -1 && !system_wide) + PARSE_OPT_STOP_AT_NON_OPTION); + if (!argc && target_pid == -1 && (!system_wide || profile_cpu == -1)) usage_with_options(record_usage, options); + symbol__init(); + if (!nr_counters) { nr_counters = 1; attrs[0].type = PERF_TYPE_HARDWARE; |