diff options
Diffstat (limited to 'tools/perf/util/header.c')
| -rw-r--r-- | tools/perf/util/header.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 6a9c041134bb..76c0b2c49eb8 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2218,15 +2218,29 @@ int perf_event__synthesize_tracing_data(int fd, struct perf_evlist *evlist, struct perf_session *session __unused) { union perf_event ev; + struct tracing_data *tdata; ssize_t size = 0, aligned_size = 0, padding; int err __used = 0; + /* + * We are going to store the size of the data followed + * by the data contents. Since the fd descriptor is a pipe, + * we cannot seek back to store the size of the data once + * we know it. Instead we: + * + * - write the tracing data to the temp file + * - get/write the data size to pipe + * - write the tracing data from the temp file + * to the pipe + */ + tdata = tracing_data_get(&evlist->entries, fd, true); + if (!tdata) + return -1; + memset(&ev, 0, sizeof(ev)); ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA; - size = read_tracing_data_size(fd, &evlist->entries); - if (size <= 0) - return size; + size = tdata->size; aligned_size = ALIGN(size, sizeof(u64)); padding = aligned_size - size; ev.tracing_data.header.size = sizeof(ev.tracing_data); @@ -2234,7 +2248,12 @@ int perf_event__synthesize_tracing_data(int fd, struct perf_evlist *evlist, process(&ev, NULL, session); - err = read_tracing_data(fd, &evlist->entries); + /* + * The put function will copy all the tracing data + * stored in temp file to the pipe. + */ + tracing_data_put(tdata); + write_padded(fd, NULL, 0, padding); return aligned_size; |