On Fri, Jul 19, 2024 at 11:26 AM Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > On Tue, Jul 16, 2024 at 12:25 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote: > > > > On Mon, Jul 15, 2024 at 09:48:58AM -0700, Kyle Huey wrote: > > > On Mon, Jul 15, 2024 at 9:30 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > > > > > > > > On Mon, Jul 15, 2024 at 08:19:44AM -0700, Kyle Huey wrote: > > > > > > > > > I think this would probably work but stealing the bit seems far more > > > > > complicated than just gating on perf_event_is_tracing(). > > > > > > > > perf_event_is_tracing() is something like 3 branches. It is not a simple > > > > conditional. Combined with that re-load and the wrong return value, this > > > > all wants a cleanup. > > > > > > > > Using that LSB works, it's just that the code aint pretty. > > > > > > Maybe we could gate on !event->tp_event instead. Somebody who is more > > > familiar with this code than me should probably confirm that tp_event > > > being non-null and perf_event_is_tracing() being true are equivalent > > > though. > > > > > > > it looks like that's the case, AFAICS tracepoint/kprobe/uprobe events > > are the only ones having the tp_event pointer set, Masami? > > > > fwiw I tried to run bpf selftests with that and it's fine > > Why can't we do the most straightforward thing in this case? > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index ab6c4c942f79..cf4645b26c90 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -9707,7 +9707,8 @@ static int __perf_event_overflow(struct perf_event *event, > > ret = __perf_event_account_interrupt(event, throttle); > > - if (event->prog && !bpf_overflow_handler(event, data, regs)) > + if (event->prog && event->prog->type == BPF_PROG_TYPE_PERF_EVENT && > + !bpf_overflow_handler(event, data, regs)) > return ret; > > > > > > jirka > > Yes, that's effectively equivalent to calling perf_event_is_tracing() and would work too. Do you want to land that patch? It needs to go to 6.10 stable too. - Kyle
