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SubjectRe: [PATCH] perf: Fix missing raw data on tracepoint events
Date
On Wed, 12 Oct 2022 15:38:57 +0100 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.

I was also getting similar issue[1], and confirmed that this fixes it. Thank
you for the fix! Also, thank you for pointing me to this patch, Namhyung!

>
> 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>

Tested-by: SeongJae Park <sj@kernel.org>


[1] https://lore.kernel.org/bpf/20221017192744.1403-1-sj@kernel.org/

Thanks,
SJ

> ---
> 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

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