| Message ID | 20170523163134.saalqlizp5opc5tz@hirez.programming.kicks-ass.net |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
On 5/23/17 9:31 AM, Peter Zijlstra wrote: > On Tue, May 23, 2017 at 07:38:08AM -0700, Alexei Starovoitov wrote: >> On 5/23/17 12:42 AM, Peter Zijlstra wrote: >>> On Mon, May 22, 2017 at 03:48:39PM -0700, Alexei Starovoitov wrote: >>>> From: Teng Qin <qinteng@fb.com> >>>> >>>> This commit adds support for attach BPF program to RAW and HW_CACHE type >>>> events, and support for read HW_CACHE type event counters in BPF >>>> program. Existing code logic already supports them, so this commit is >>>> just update Enum value checks. >>> >>> So what I'm missing is why they were not supported previously, and what >>> changed to allow it now. >> >> that code path simply wasn't tested previously. Nothing changed on >> bpf side and on perf side. >> Why it wasn't added on day one? There was no demand. Now people >> use bpf more and more and few folks got confused that these types >> of perf events were not supported, hence we're adding it. > > OK. Is there anything stopping people from wanting to use the dynamic > types, as found in: > > /sys/bus/event_source/devices/*/type > > ? > > In which case, do we want something like this instead? > > > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 971f7259108f..4aa5f3011cf8 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -8063,12 +8063,8 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) > bool is_kprobe, is_tracepoint; > struct bpf_prog *prog; > > - if (event->attr.type == PERF_TYPE_HARDWARE || > - event->attr.type == PERF_TYPE_SOFTWARE) > - return perf_event_set_bpf_handler(event, prog_fd); > - > if (event->attr.type != PERF_TYPE_TRACEPOINT) > - return -EINVAL; > + return perf_event_set_bpf_handler(event, prog_fd); Good point. We were actually looking at how to deal with msr and cstate events. That should indeed address it. Will respin. Thanks for the feedback!
diff --git a/kernel/events/core.c b/kernel/events/core.c index 971f7259108f..4aa5f3011cf8 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -8063,12 +8063,8 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd) bool is_kprobe, is_tracepoint; struct bpf_prog *prog; - if (event->attr.type == PERF_TYPE_HARDWARE || - event->attr.type == PERF_TYPE_SOFTWARE) - return perf_event_set_bpf_handler(event, prog_fd); - if (event->attr.type != PERF_TYPE_TRACEPOINT) - return -EINVAL; + return perf_event_set_bpf_handler(event, prog_fd); if (event->tp_event->prog) return -EEXIST;