Messages in this thread | | | Date | Wed, 14 Jan 2015 09:50:25 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v2] perf: fix dwarf unwind using libunwind. |
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Em Wed, Jan 14, 2015 at 12:57:49PM +0100, Jiri Olsa escreveu: > On Wed, Jan 14, 2015 at 10:36:47AM +0800, Wang Nan wrote: > > Perf tool fails to unwind user stack if the event raises in a shared > > SNIP > > > + > > __attribute__ ((noinline)) > > static int krava_3(struct thread *thread) > > { > > - return unwind_thread(thread); > > + struct thread *array[2] = {thread, thread}; > > + void *fp = &bsearch; > > + /* > > + * make _bsearch a volatile function pointer to > > + * prevent potential optimization, which may expand > > + * bsearch and call compare directly from this function, > > + * instead of libc shared object. > > + */ > > + void *(*volatile _bsearch)(void *, void *, size_t, > > + size_t, int (*)(void *, void *)); > > + > > + _bsearch = fp; > > + _bsearch(array, &thread, 2, sizeof(struct thread **), compare); > > + return global_unwind_retval; > > } > > ah, I've got confused with the NO_LIBUNWIND_DEBUG_FRAME name > and got the impression that we could use it in the tests/make > as another compile option test.. > > but your change is even better ;-) thanks for updating this test > > > Acked-by: Jiri Olsa <jolsa@kernel.org>
Thanks, applied to perf/urgent.
- Arnaldo
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