Re: [PATCH] perf: Fix header.size for namespace events

[Peter Zijlstra <peterz@infradead.org>]

On Fri, Oct 27, 2017 at 09:43:11AM +0200, Jiri Olsa wrote:
> Reset header size for namespace events, otherwise
> it only gets bigger in ctx iterations.
> 
> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
> Link: http://lkml.kernel.org/n/tip-nlo4gonz9d4guyb8153ukzt0@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>

Fixes: e422267322cd ("perf: Add PERF_RECORD_NAMESPACES to include namespaces related info")

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

> ---
>  kernel/events/core.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 04989fb769f0..4e6aa3f7d018 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -6717,6 +6717,7 @@ static void perf_event_namespaces_output(struct perf_event *event,
>  	struct perf_namespaces_event *namespaces_event = data;
>  	struct perf_output_handle handle;
>  	struct perf_sample_data sample;
> +	u16 header_size = namespaces_event->event_id.header.size;
>  	int ret;
>  
>  	if (!perf_event_namespaces_match(event))
> @@ -6727,7 +6728,7 @@ static void perf_event_namespaces_output(struct perf_event *event,
>  	ret = perf_output_begin(&handle, event,
>  				namespaces_event->event_id.header.size);
>  	if (ret)
> -		return;
> +		goto out;
>  
>  	namespaces_event->event_id.pid = perf_event_pid(event,
>  							namespaces_event->task);
> @@ -6739,6 +6740,8 @@ static void perf_event_namespaces_output(struct perf_event *event,
>  	perf_event__output_id_sample(event, &handle, &sample);
>  
>  	perf_output_end(&handle);
> +out:
> +	namespaces_event->event_id.header.size = header_size;
>  }
>  
>  static void perf_fill_ns_link_info(struct perf_ns_link_info *ns_link_info,
> -- 
> 2.13.6
>