Re: [PATCH 05/16] perf: Add attribute to filter out user callchains

[Peter Zijlstra]

On Wed, 2012-05-23 at 21:32 +0200, Jiri Olsa wrote:
> Add the new exclude_user_callchain attribute to filter out
> frame pointer based user callchains.
> 
> This is something we want to select when we use the dwarf cfi
> callchain mode, because frame pointer based user callchains are
> useless in this mode.
> 
> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
>  include/linux/perf_event.h |    4 +++-
>  kernel/events/callchain.c  |    4 ++--
>  kernel/events/core.c       |    3 ++-
>  kernel/events/internal.h   |    3 ++-
>  4 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index dcdc97e..df6ba37 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -275,7 +275,9 @@ struct perf_event_attr {
>  				exclude_host   :  1, /* don't count in host   */
>  				exclude_guest  :  1, /* don't count in guest  */
>  
> -				__reserved_1   : 43;
> +				exclude_user_callchain : 1, /* only record kernel callchains */

*sigh* I guess if we're going to do this we might as well do a complete
option set and also allow excluding kernel and possible hv if anybody
actually implemented that.

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