- input = open(input_name, O_RDONLY);
- if (input < 0) {
- perror("failed to open file");
- exit(-1);
- }
-
- ret = fstat(input, &perf_stat);
- if (ret < 0) {
- perror("failed to stat file");
- exit(-1);
- }
-
- if (!perf_stat.st_size) {
- fprintf(stderr, "zero-sized file, nothing to do!\n");
- exit(0);
- }
- header = perf_header__read(input);
- head = header->data_offset;
- sample_type = perf_header__sample_type(header);
-
- if (!(sample_type & PERF_SAMPLE_RAW))
- die("No trace sample to read. Did you call perf record "
- "without -R?");
-
- if (load_kernel() < 0) {
- perror("failed to load kernel symbols");
- return EXIT_FAILURE;
- }
-
-remap:
- buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
- MAP_SHARED, input, offset);
- if (buf == MAP_FAILED) {
- perror("failed to mmap file");
- exit(-1);
- }
-
-more:
- event = (event_t *)(buf + head);
-
- size = event->header.size;
- if (!size)
- size = 8;
-
- if (head + event->header.size >= page_size * mmap_window) {
- unsigned long shift = page_size * (head / page_size);
- int res;
-
- res = munmap(buf, page_size * mmap_window);
- assert(res == 0);
-
- offset += shift;
- head -= shift;
- goto remap;
- }
-
- size = event->header.size;
-
-
- if (!size || process_event(event, offset, head) < 0) {
-
- /*
- * assume we lost track of the stream, check alignment, and
- * increment a single u64 in the hope to catch on again 'soon'.
- */
-
- if (unlikely(head & 7))
- head &= ~7ULL;
-
- size = 8;
- }
-
- head += size;
-
- if (offset + head < (unsigned long)perf_stat.st_size)
- goto more;
-
- rc = EXIT_SUCCESS;
- close(input);
-
- return rc;