Messages in this thread | | | Date | Tue, 30 Oct 2012 21:29:16 +0100 | Subject | [BUG] perf tools: does not process data mmaps correctly | From | Stephane Eranian <> |
| |
Arnaldo,
A long time ago, I brought up the issue of perf failing to resolve data symbols despite having the MAP__VARIABLE map type.
Now that I have posted the PEBS-LL patch series, there is a test case to debug this.
I looked again at it today. Start from ip__resolve_data() in my patchset. IT is looking for a data symbol given an address.
Seems to me the core of the problem is how perf processes the MMAP records in machine__process_mmap_event():
int machine__process_mmap_event(struct machine *machine, union perf_event *event) { ...
thread = machine__findnew_thread(machine, event->mmap.pid); if (thread == NULL) goto out_problem; map = map__new(&machine->user_dsos, event->mmap.start, event->mmap.len, event->mmap.pgoff, event->mmap.pid, event->mmap.filename, MAP__FUNCTION);
I don't see any effort to distinguish code from data here. All mmaps are treated as code.
That could be fine, if then you drop MAP__VARIABLE.
So how is this supposed to work?
Thanks.
| |