perf_read_tsc_conversion
err = perf_read_tsc_conversion(pc, &tc);
err = perf_read_tsc_conversion(pc, &tc);
ret = perf_read_tsc_conversion(pc, &tc);
err = perf_read_tsc_conversion(pc, &tc);
int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,