On Mon, Dec 4, 2023 at 12:14 PM Kyle Huey <me@xxxxxxxxxxxx> wrote:
>
> Returning zero from a bpf program attached to a perf event already
> suppresses any data output. This allows it to suppress I/O availability
> signals too.
make sense, just one question below
>
> Signed-off-by: Kyle Huey <khuey@xxxxxxxxxxxx>
> ---
> kernel/events/core.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index b704d83a28b2..34d7b19d45eb 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -10417,8 +10417,10 @@ static void bpf_overflow_handler(struct perf_event *event,
> rcu_read_unlock();
> out:
> __this_cpu_dec(bpf_prog_active);
> - if (!ret)
> + if (!ret) {
> + event->pending_kill = 0;
> return;
> + }
What's the distinction between event->pending_kill and
event->pending_wakeup? Should we do something about pending_wakeup?
Asking out of complete ignorance of all these perf specifics.
>
> event->orig_overflow_handler(event, data, regs);
> }
> --
> 2.34.1
>
>
