Hi,
With the latest tip.git perf, if you run $ perf record -a -o - sleep 2 | perf inject -b -i - | perf buildid-list -i - SEGFAULT in perf inject: free_dup_event (oe=0x555555d25b88, oe=0x555555d25b88, event=0x3030310931303031) at util/ordered-events.c:86 86 oe->cur_alloc_size -= event->header.size; (gdb) bt #0 free_dup_event (oe=0x555555d25b88, oe=0x555555d25b88, event=0x3030310931303031) at util/ordered-events.c:86 #1 ordered_events__free (oe=oe@entry=0x555555d25b88) at util/ordered-events.c:310 #2 0x00005555557964f8 in __perf_session__process_pipe_events (session=0x555555d1f910) at util/session.c:1778 #3 perf_session__process_events (session=session@entry=0x555555d1f910) at util/session.c:1958 #4 0x00005555556ef9b2 in __cmd_inject (inject=0x7fffffffda40) at builtin-inject.c:697 #5 cmd_inject (argc=<optimized out>, argv=<optimized out>) at builtin-inject.c:871 #6 0x000055555572e8b1 in run_builtin (p=0x555555be8f98 <commands+600>, argc=4, argv=0x7fffffffe460) at perf.c:303 #7 0x000055555572ebae in handle_internal_command (argc=4, argv=0x7fffffffe460) at perf.c:355 #8 0x00005555556ae1e1 in run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:399 #9 main (argc=<optimized out>, argv=0x7fffffffe460) at perf.c:521 In general I think the pipe mode is not very well tested. I think it could be made the default file format. I believe perf can autodetect file vs. pipe mode perf.data using the header.size field. This would simplify a few things inside perf and ensure the pipe mode format is well tested.