Re: [PATCH v6 04/11] perf tools: Move unwind__prepare_access from thread_new into thread__insert_map

[Jiri Olsa <jolsa@redhat.com>]

On Sat, May 28, 2016 at 11:59:53AM +0000, He Kuang wrote:
> For determine the libunwind methods to use, we should get the
> 32bit/64bit information from maps of a thread. When a thread is newly
> created, the information is not prepared. This patch moves
> unwind__prepare_access() into thread__insert_map() so we can get the
> information we need from maps.
> 
> Signed-off-by: He Kuang <hekuang@huawei.com>
> ---
>  tools/perf/util/thread.c           | 7 ++-----
>  tools/perf/util/unwind-libunwind.c | 7 +++----
>  2 files changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
> index 6d3900c..045477d 100644
> --- a/tools/perf/util/thread.c
> +++ b/tools/perf/util/thread.c
> @@ -43,11 +43,6 @@ struct thread *thread__new(pid_t pid, pid_t tid)
>  		thread->cpu = -1;
>  		INIT_LIST_HEAD(&thread->comm_list);
>  
> -		register_local_unwind_libunwind_ops(thread);
> -
> -		if (unwind__prepare_access(thread) < 0)
> -			goto err_thread;
> -
>  		comm_str = malloc(32);
>  		if (!comm_str)
>  			goto err_thread;
> @@ -207,6 +202,8 @@ void thread__insert_map(struct thread *thread, struct map *map)
>  {
>  	map_groups__fixup_overlappings(thread->mg, map, stderr);
>  	map_groups__insert(thread->mg, map);
> +
> +	unwind__prepare_access(thread);

so thread__insert_map does not return value,
I think we should change it now when it calls
unwind__prepare_access

I was also thinking to keepcall unwind__prepare_access
separatelly but this function seems to fit better

thanks,
jirka