Messages in this thread | | | Date | Fri, 24 Jul 2015 09:57:14 +0800 | From | xiakaixu <> | Subject | Re: [PATCH v3 2/3] bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter |
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于 2015/7/24 6:56, Alexei Starovoitov 写道: > On 7/23/15 2:42 AM, Kaixu Xia wrote: >> According to the perf_event_map_fd and index, the function >> bpf_perf_event_read() can convert the corresponding map >> value to the pointer to struct perf_event and return the >> Hardware PMU counter value. >> >> Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> > ... >> +static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5) >> +{ >> + struct bpf_map *map = (struct bpf_map *) (unsigned long) r1; >> + struct bpf_array *array = container_of(map, struct bpf_array, map); >> + struct perf_event *event; >> + >> + if (index >= array->map.max_entries) >> + return -E2BIG; >> + >> + event = array->events[index]; >> + if (!event) >> + return -EBADF; > > probably ENOENT makes more sense here. > >> + >> + if (event->state != PERF_EVENT_STATE_ACTIVE) >> + return -ENOENT; > > and -EINVAL here?
Yeah, the errno is better.
Thanks! > > > . >
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