From d0cabbb021bee5c4b831a0235af9534ad07f8d3d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:40 -0700 Subject: tools: bpf: move the event reading loop to libbpf There are two copies of event reading loop - in bpftool and trace_helpers "library". Consolidate them and move the code to libbpf. Return codes from trace_helpers are kept, but renamed to include LIBBPF prefix. Suggested-by: Alexei Starovoitov Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/trace_helpers.c | 87 ++++++++++------------------- 1 file changed, 30 insertions(+), 57 deletions(-) (limited to 'tools/testing/selftests/bpf/trace_helpers.c') diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index ad025bd75f1c..8fb4fe8686e4 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -74,7 +74,7 @@ struct ksym *ksym_search(long key) static int page_size; static int page_cnt = 8; -static volatile struct perf_event_mmap_page *header; +static struct perf_event_mmap_page *header; int perf_event_mmap(int fd) { @@ -107,74 +107,47 @@ struct perf_event_sample { char data[]; }; -static int perf_event_read(perf_event_print_fn fn) +static enum bpf_perf_event_ret bpf_perf_event_print(void *event, void *priv) { - __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - __u64 buffer_size = page_cnt * page_size; - void *base, *begin, *end; - char buf[256]; + struct perf_event_sample *e = event; + perf_event_print_fn fn = priv; int ret; - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return PERF_EVENT_CONT; - - base = ((char *)header) + page_size; - - begin = base + data_tail % buffer_size; - end = base + data_head % buffer_size; - - while (begin != end) { - struct perf_event_sample *e; - - e = begin; - if (begin + e->header.size > base + buffer_size) { - long len = base + buffer_size - begin; - - assert(len < e->header.size); - memcpy(buf, begin, len); - memcpy(buf + len, base, e->header.size - len); - e = (void *) buf; - begin = base + e->header.size - len; - } else if (begin + e->header.size == base + buffer_size) { - begin = base; - } else { - begin += e->header.size; - } - - if (e->header.type == PERF_RECORD_SAMPLE) { - ret = fn(e->data, e->size); - if (ret != PERF_EVENT_CONT) - return ret; - } else if (e->header.type == PERF_RECORD_LOST) { - struct { - struct perf_event_header header; - __u64 id; - __u64 lost; - } *lost = (void *) e; - printf("lost %lld events\n", lost->lost); - } else { - printf("unknown event type=%d size=%d\n", - e->header.type, e->header.size); - } + if (e->header.type == PERF_RECORD_SAMPLE) { + ret = fn(e->data, e->size); + if (ret != LIBBPF_PERF_EVENT_CONT) + return ret; + } else if (e->header.type == PERF_RECORD_LOST) { + struct { + struct perf_event_header header; + __u64 id; + __u64 lost; + } *lost = (void *) e; + printf("lost %lld events\n", lost->lost); + } else { + printf("unknown event type=%d size=%d\n", + e->header.type, e->header.size); } - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_head; - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } int perf_event_poller(int fd, perf_event_print_fn output_fn) { - int ret; + enum bpf_perf_event_ret ret; + void *buf = NULL; + size_t len = 0; for (;;) { perf_event_poll(fd); - ret = perf_event_read(output_fn); - if (ret != PERF_EVENT_CONT) - return ret; + ret = bpf_perf_event_read_simple(header, page_cnt * page_size, + page_size, &buf, &len, + bpf_perf_event_print, + output_fn); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; } + free(buf); - return PERF_EVENT_DONE; + return ret; } -- cgit v1.2.3-59-g8ed1b