Messages in this thread | | | Date | Fri, 24 Jul 2015 09:54:01 +0800 | From | xiakaixu <> | Subject | Re: [PATCH v3 3/3] samples/bpf: example of get selected PMU counter value |
| |
于 2015/7/24 6:59, Alexei Starovoitov 写道: > On 7/23/15 2:42 AM, Kaixu Xia wrote: >> This is a simple example and shows how to use the new ability >> to get the selected Hardware PMU counter value. >> >> Signed-off-by: Kaixu Xia <xiakaixu@huawei.com> > ... >> +struct bpf_map_def SEC("maps") my_map = { >> + .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY, >> + .key_size = sizeof(int), >> + .value_size = sizeof(unsigned long), >> + .max_entries = 32, >> +}; > > wait. how did it work here? value_size should be u32.
I tested the whole thing on ARM board. You are ringt, it should be u32. When create the array map, we choose the array->elem_size as round_up(attr->value_size, 8), why 8?
Thanks! > > >
| |