> On Jun 25, 2019, at 11:12 PM, Andrii Nakryiko <andriin@xxxxxx> wrote: > > BPF_MAP_TYPE_PERF_EVENT_ARRAY map is often used to send data from BPF program > to user space for additional processing. libbpf already has very low-level API > to read single CPU perf buffer, bpf_perf_event_read_simple(), but it's hard to > use and requires a lot of code to set everything up. This patch adds > perf_buffer abstraction on top of it, abstracting setting up and polling > per-CPU logic into simple and convenient API, similar to what BCC provides. > > perf_buffer__new() sets up per-CPU ring buffers and updates corresponding BPF > map entries. It accepts two user-provided callbacks: one for handling raw > samples and one for get notifications of lost samples due to buffer overflow. > > perf_buffer__poll() is used to fetch ring buffer data across all CPUs, > utilizing epoll instance. > > perf_buffer__free() does corresponding clean up and unsets FDs from BPF map. > > All APIs are not thread-safe. User should ensure proper locking/coordination if > used in multi-threaded set up. > > Signed-off-by: Andrii Nakryiko <andriin@xxxxxx> Acked-by: Song Liu <songliubraving@xxxxxx> > --- > tools/lib/bpf/libbpf.c | 282 +++++++++++++++++++++++++++++++++++++++ > tools/lib/bpf/libbpf.h | 12 ++ > tools/lib/bpf/libbpf.map | 5 +- > 3 files changed, 298 insertions(+), 1 deletion(-)
