bpf中的数据结构bpf_perf_event_data解析 1 前言 在系统性能运维监控的一些场景中我们往往需要对系统进行"采样"分析,最场景的例子就是perf top/record;在使用ebpf+perf event的情况下,ebpf中使用SEC("perf_event")这个名字的section来作为perf event的prog程序。 这类程序有着固定的参数类型:struct bpf_perf_event...
首先,对于BPF_MAP_TYPE_PERF_EVENT_ARRAY类型的maps要特殊一些,在定义时一般不用指定max_entries;不指定的话libbpf会调用接口函数map_set_def_max_entries中会默认将max_entries设置为nr_cpus。 我们再来回顾一下它的定义,只定义了map type、key_size, value_size: /*BPF perfbuf map*/struct{ __uint(type, ...
bpf fentry/fexit programs - which added in 5.11 I think this is a pretty reasonable trade off if you read theman pageofbpf_perf_event_read_value If youreallywant 5.4 then we can discuss that as it's not trivial.
2.6 Event Sources 45 2.7 kprobes 46 2.7.1 How kprobes Work 46 2.7.2 kprobes Interfaces 47 2.7.3 BPF and kprobes 48 2.7.4 kprobes Additional Reading 49 2.8 uprobes 49 2.8.1 How uprobes Work 49 2.8.2 Uprobes Interfaces 51 2.8.3 BPF and uprobes 51 2.8.4 uprobes Overhead and Future...
Following up to #785, is there a reason we are not syncing include/uapi/linux/bpf_perf_event.h to the libbpf local includes, or was it an oversight? I have a change [1] which add this and enables x86 builds, but ultimately, would introdu...
Beyond self-explanatoryLICENSEandREADME.mdthe rest oflibbpf-bootstrapis contained in aexamples/csub-directory. Makefiledefines the necessary build rules to compile all the supplied (and your custom ones) BPF apps. It follows a simple file naming convention: ...
bpf_source = """ #include #include #include <linux/sched.h> struct trace_t { int stack_id; } BPF_HASH(cache, struct trace_t); BPF_STACK_TRACE(traces, 10000); """ Initialize a structure that will store the reference identifier for each one of the stack frames that our profiler...
.type = PERF_TYPE_SOFTWARE, .freq = 1, .sample_period = freq, .config = PERF_COUNT_SW_CPU_CLOCK, .inherit = 1, }; ... pmu_fd[i] = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i, -1 /* group_fd */, 0 /* flags */); ...
bpftool map event_pipe MAP [cpu N index M] Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map. Install perf rings into a perf event array map and dump output of any bpf_perf_event_output() call in the kernel. By default read the number of CPUs on the system and install perf ...
(type, BPF_MAP_TYPE_PERCPU_ARRAY);@@ -35,7 +34,7 @@bpf_get_current_comm(&e->comm, sizeof(e->comm));bpf_probe_read_str(&e->filename, sizeof(e->filename), (void *)ctx + fname_off);- bpf_perf_event_output(ctx, &pb, BPF_F_CURRENT_CPU, e, sizeof(*e));+ bpf_...