diff options
| -rw-r--r-- | tools/perf/util/evlist.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 814e954c1318..3b366c085021 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1061,6 +1061,8 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *tar } if (!evlist->workload.pid) { + int ret; + if (pipe_output) dup2(2, 1); @@ -1078,8 +1080,22 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *tar /* * Wait until the parent tells us to go. */ - if (read(go_pipe[0], &bf, 1) == -1) - perror("unable to read pipe"); + ret = read(go_pipe[0], &bf, 1); + /* + * The parent will ask for the execvp() to be performed by + * writing exactly one byte, in workload.cork_fd, usually via + * perf_evlist__start_workload(). + * + * For cancelling the workload without actuallin running it, + * the parent will just close workload.cork_fd, without writing + * anything, i.e. read will return zero and we just exit() + * here. + */ + if (ret != 1) { + if (ret == -1) + perror("unable to read pipe"); + exit(ret); + } execvp(argv[0], (char **)argv); |