On Wed, Aug 31, 2016 at 02:50:41PM -0700, Alexei Starovoitov wrote: > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h > index 97bfe62f30d7..dcaaaf3ec8e6 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -679,6 +679,8 @@ struct perf_event { > u64 (*clock)(void); > perf_overflow_handler_t overflow_handler; > void *overflow_handler_context;
> + perf_overflow_handler_t orig_overflow_handler; > + struct bpf_prog *prog; Should we put that under CONFIG_BPF_SYSCALL too? > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 3cfabdf7b942..305433ab2447 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -7637,11 +7637,75 @@ static void perf_event_free_filter(struct perf_event > *event) > ftrace_profile_free_filter(event); > } > > +static void bpf_overflow_handler(struct perf_event *event, > + struct perf_sample_data *data, > + struct pt_regs *regs) > +{ > + struct bpf_perf_event_data_kern ctx = { > + .data = data, > + .regs = regs, > + }; > + int ret = 0; > + > +#ifdef CONFIG_BPF_SYSCALL > + preempt_disable(); > + if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) > + goto out; > + rcu_read_lock(); > + ret = BPF_PROG_RUN(event->prog, (void *)&ctx); > + rcu_read_unlock(); > + out: Please, no leading space before labels. Use something like: [diff "default"] xfuncname = "^[[:alpha:]$_].*[^:]$" In your .gitconfig if you want to keep diff output 'sane'. > + __this_cpu_dec(bpf_prog_active); > + preempt_enable(); > +#endif > + if (!ret) > + return; > + > + event->orig_overflow_handler(event, data, regs); > +} Other than that, ACK.