perf record: Propagate exit status of a command line workload

Currently perf record doesn't propagate the exit status of a workload
given by the command line.  But sometimes it'd useful if it's
propagated so that a monitoring script can handle errors
appropriately.

To do that, it moves most of logic out of the exit handlers and run
them directly in the __cmd_record().  The only thing needs to be done
in the handler is propagating terminating signal so that the shell can
terminate its loop properly when Ctrl-C was pressed.  Also it cleaned
up the resource management code in record__exit().

With this change, perf record returns the child exit status in case of
normal termination and send signal to itself when terminated by signal.

Example run of Stephane's case:

  $ perf record true && echo yes || echo no
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (~589 samples) ]
  yes

  $ perf record false && echo yes || echo no
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (~589 samples) ]
  no

Jiri's case (error in parent):

  $ perf record -m 10G true && echo yes || echo no
  rounding mmap pages size to 17179869184 bytes (4194304 pages)
  failed to mmap with 12 (Cannot allocate memory)
  no

  $ ulimit -n 6
  $ perf record sleep 1 && echo yes || echo no
  failed to create 'go' pipe: Too many open files
  Couldn't run the workload!
  no

And Peter's case (interrupted by signal):

  $ while :; do perf record sleep 1; done
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.014 MB perf.data (~593 samples) ]

Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1399855645-25815-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8ce62ef..2e0d484 100644 (file)
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -147,29 +147,19 @@ static void sig_handler(int sig)
 {
        if (sig == SIGCHLD)
                child_finished = 1;
+       else
+               signr = sig;
 
        done = 1;
-       signr = sig;
 }
 
-static void record__sig_exit(int exit_status __maybe_unused, void *arg)
+static void record__sig_exit(void)
 {
-       struct record *rec = arg;
-       int status;
-
-       if (rec->evlist->workload.pid > 0) {
-               if (!child_finished)
-                       kill(rec->evlist->workload.pid, SIGTERM);
-
-               wait(&status);
-               if (WIFSIGNALED(status))
-                       psignal(WTERMSIG(status), rec->progname);
-       }
-
-       if (signr == -1 || signr == SIGUSR1)
+       if (signr == -1)
                return;
 
        signal(signr, SIG_DFL);
+       raise(signr);
 }
 
 static int record__open(struct record *rec)
@@ -243,27 +233,6 @@ static int process_buildids(struct record *rec)
                                              size, &build_id__mark_dso_hit_ops);
 }
 
-static void record__exit(int status, void *arg)
-{
-       struct record *rec = arg;
-       struct perf_data_file *file = &rec->file;
-
-       if (status != 0)
-               return;
-
-       if (!file->is_pipe) {
-               rec->session->header.data_size += rec->bytes_written;
-
-               if (!rec->no_buildid)
-                       process_buildids(rec);
-               perf_session__write_header(rec->session, rec->evlist,
-                                          file->fd, true);
-               perf_session__delete(rec->session);
-               perf_evlist__delete(rec->evlist);
-               symbol__exit();
-       }
-}
-
 static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
 {
        int err;
@@ -344,18 +313,19 @@ static volatile int workload_exec_errno;
  * if the fork fails, since we asked by setting its
  * want_signal to true.
  */
-static void workload_exec_failed_signal(int signo, siginfo_t *info,
+static void workload_exec_failed_signal(int signo __maybe_unused,
+                                       siginfo_t *info,
                                        void *ucontext __maybe_unused)
 {
        workload_exec_errno = info->si_value.sival_int;
        done = 1;
-       signr = signo;
        child_finished = 1;
 }
 
 static int __cmd_record(struct record *rec, int argc, const char **argv)
 {
        int err;
+       int status = 0;
        unsigned long waking = 0;
        const bool forks = argc > 0;
        struct machine *machine;
@@ -367,7 +337,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
        rec->progname = argv[0];
 
-       on_exit(record__sig_exit, rec);
+       atexit(record__sig_exit);
        signal(SIGCHLD, sig_handler);
        signal(SIGINT, sig_handler);
        signal(SIGTERM, sig_handler);
@@ -388,32 +358,28 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
                                                    workload_exec_failed_signal);
                if (err < 0) {
                        pr_err("Couldn't run the workload!\n");
+                       status = err;
                        goto out_delete_session;
                }
        }
 
        if (record__open(rec) != 0) {
                err = -1;
-               goto out_delete_session;
+               goto out_child;
        }
 
        if (!rec->evlist->nr_groups)
                perf_header__clear_feat(&session->header, HEADER_GROUP_DESC);
 
-       /*
-        * perf_session__delete(session) will be called at record__exit()
-        */
-       on_exit(record__exit, rec);
-
        if (file->is_pipe) {
                err = perf_header__write_pipe(file->fd);
                if (err < 0)
-                       goto out_delete_session;
+                       goto out_child;
        } else {
                err = perf_session__write_header(session, rec->evlist,
                                                 file->fd, false);
                if (err < 0)
-                       goto out_delete_session;
+                       goto out_child;
        }
 
        if (!rec->no_buildid
@@ -421,7 +387,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
                pr_err("Couldn't generate buildids. "
                       "Use --no-buildid to profile anyway.\n");
                err = -1;
-               goto out_delete_session;
+               goto out_child;
        }
 
        machine = &session->machines.host;
@@ -431,7 +397,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
                                                   process_synthesized_event);
                if (err < 0) {
                        pr_err("Couldn't synthesize attrs.\n");
-                       goto out_delete_session;
+                       goto out_child;
                }
 
                if (have_tracepoints(&rec->evlist->entries)) {
@@ -447,7 +413,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
                                                                  process_synthesized_event);
                        if (err <= 0) {
                                pr_err("Couldn't record tracing data.\n");
-                               goto out_delete_session;
+                               goto out_child;
                        }
                        rec->bytes_written += err;
                }
@@ -475,7 +441,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
        err = __machine__synthesize_threads(machine, tool, &opts->target, rec->evlist->threads,
                                            process_synthesized_event, opts->sample_address);
        if (err != 0)
-               goto out_delete_session;
+               goto out_child;
 
        if (rec->realtime_prio) {
                struct sched_param param;
@@ -484,7 +450,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
                if (sched_setscheduler(0, SCHED_FIFO, &param)) {
                        pr_err("Could not set realtime priority.\n");
                        err = -1;
-                       goto out_delete_session;
+                       goto out_child;
                }
        }
 
@@ -512,13 +478,15 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
                if (record__mmap_read_all(rec) < 0) {
                        err = -1;
-                       goto out_delete_session;
+                       goto out_child;
                }
 
                if (hits == rec->samples) {
                        if (done)
                                break;
                        err = poll(rec->evlist->pollfd, rec->evlist->nr_fds, -1);
+                       if (err < 0 && errno == EINTR)
+                               err = 0;
                        waking++;
                }
 
@@ -538,28 +506,52 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
                const char *emsg = strerror_r(workload_exec_errno, msg, sizeof(msg));
                pr_err("Workload failed: %s\n", emsg);
                err = -1;
-               goto out_delete_session;
+               goto out_child;
        }
 
-       if (quiet || signr == SIGUSR1)
-               return 0;
+       if (!quiet) {
+               fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
 
-       fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
+               /*
+                * Approximate RIP event size: 24 bytes.
+                */
+               fprintf(stderr,
+                       "[ perf record: Captured and wrote %.3f MB %s (~%" PRIu64 " samples) ]\n",
+                       (double)rec->bytes_written / 1024.0 / 1024.0,
+                       file->path,
+                       rec->bytes_written / 24);
+       }
 
-       /*
-        * Approximate RIP event size: 24 bytes.
-        */
-       fprintf(stderr,
-               "[ perf record: Captured and wrote %.3f MB %s (~%" PRIu64 " samples) ]\n",
-               (double)rec->bytes_written / 1024.0 / 1024.0,
-               file->path,
-               rec->bytes_written / 24);
+out_child:
+       if (forks) {
+               int exit_status;
 
-       return 0;
+               if (!child_finished)
+                       kill(rec->evlist->workload.pid, SIGTERM);
+
+               wait(&exit_status);
+
+               if (err < 0)
+                       status = err;
+               else if (WIFEXITED(exit_status))
+                       status = WEXITSTATUS(exit_status);
+               else if (WIFSIGNALED(exit_status))
+                       signr = WTERMSIG(exit_status);
+       } else
+               status = err;
+
+       if (!err && !file->is_pipe) {
+               rec->session->header.data_size += rec->bytes_written;
+
+               if (!rec->no_buildid)
+                       process_buildids(rec);
+               perf_session__write_header(rec->session, rec->evlist,
+                                          file->fd, true);
+       }
 
 out_delete_session:
        perf_session__delete(session);
-       return err;
+       return status;
 }
 
 #define BRANCH_OPT(n, m) \
@@ -988,6 +980,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 
        err = __cmd_record(&record, argc, argv);
 out_symbol_exit:
+       perf_evlist__delete(rec->evlist);
        symbol__exit();
        return err;
 }