Re: [PATCH] perf: Fix missing raw data on tracepoint events

[Athira Rajeev <atrajeev@linux.vnet.ibm.com>]

> On 12-Oct-2022, at 8:08 PM, James Clark <james.clark@arm.com> wrote:
> 
> Since commit 838d9bb62d13 ("perf: Use sample_flags for raw_data")
> raw data is not being output on tracepoints due to the PERF_SAMPLE_RAW
> field not being set. Fix this by setting it for tracepoint events.
> 
> This fixes the following test failure:
> 
>  perf test "sched_switch" -vvv
> 
>   35: Track with sched_switch
>  --- start ---
>  test child forked, pid 1828
>  ...
>  Using CPUID 0x00000000410fd400
>  sched_switch: cpu: 2 prev_tid -14687 next_tid 0
>  sched_switch: cpu: 2 prev_tid -14687 next_tid 0
>  Missing sched_switch events
>  4613 events recorded
>  test child finished with -1
>  ---- end ----
>  Track with sched_switch: FAILED!
> 
> Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data")
> Cc: Namhyung Kim <namhyung@kernel.org>
> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
> Signed-off-by: James Clark <james.clark@arm.com>

Hi James, 

Thanks for the fix. I was getting similar issue with “perf trace” and it works with this fix.

Tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>


> ---
> kernel/events/core.c | 1 +
> 1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index b981b879bcd8..824c23830272 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -9759,6 +9759,7 @@ void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
> 
> 	perf_sample_data_init(&data, 0, 0);
> 	data.raw = &raw;
> +	data.sample_flags |= PERF_SAMPLE_RAW;
> 
> 	perf_trace_buf_update(record, event_type);
> 
> -- 
> 2.28.0
>