Messages in this thread | | | Date | Fri, 2 Aug 2019 15:30:39 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH 2/2] perf unwind: fix libunwind when tid != pid |
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On Mon, Jul 29, 2019 at 06:24:30PM +0100, John Keeping wrote: > Commit e5adfc3e7e77 ("perf map: Synthesize maps only for thread group > leader") changed the recording side so that we no longer get mmap events > for threads other than the thread group leader. > > When a file recorded after this change is loaded, the lack of mmap > records mean that unwinding is not set up for any other threads.
sry I dont' follow what's the problem here, could you please describe the scenrio where the current code is failing in more details
> > Following the rationale in that commit, move the libunwind fields into > struct map_groups and update the libunwind functions to take this > instead of the struct thread. This is only required for > unwind__finish_access which must now be called from map_groups__delete > and the others are changed for symmetry. > > Note that unwind__get_entries keeps the thread argument since it is > required for symbol lookup and the libdw unwind provider uses the thread > ID.
SNIP
> @@ -59,37 +59,31 @@ int unwind__prepare_access(struct thread *thread, struct map *map, > return 0; > } > out_register: > - unwind__register_ops(thread, ops); > + unwind__register_ops(mg, ops); > > - err = thread->unwind_libunwind_ops->prepare_access(thread); > + err = mg->unwind_libunwind_ops->prepare_access(mg); > if (initialized) > *initialized = err ? false : true; > return err; > } > > -void unwind__flush_access(struct thread *thread) > +void unwind__flush_access(struct map_groups *mg) > { > - if (!dwarf_callchain_users) > - return;
why did you remove this check?
> - > - if (thread->unwind_libunwind_ops) > - thread->unwind_libunwind_ops->flush_access(thread); > + if (mg->unwind_libunwind_ops) > + mg->unwind_libunwind_ops->flush_access(mg); > } > > -void unwind__finish_access(struct thread *thread) > +void unwind__finish_access(struct map_groups *mg) > { > - if (!dwarf_callchain_users) > - return;
why did you remove this check?
thanks, jirka
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