1 files changed, 107 insertions, 0 deletions
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
new file mode 100644
index 000000000..364b98764
--- /dev/null
+++ b/samples/bpf/trace_output_user.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <stdio.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <time.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static __u64 start_time;
+static __u64 cnt;
+
+#define MAX_CNT 100000ll
+
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
+{
+	struct {
+		__u64 pid;
+		__u64 cookie;
+	} *e = data;
+
+	if (e->cookie != 0x12345678) {
+		printf("BUG pid %llx cookie %llx sized %d\n",
+		       e->pid, e->cookie, size);
+		return;
+	}
+
+	cnt++;
+
+	if (cnt == MAX_CNT) {
+		printf("recv %lld events per sec\n",
+		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+		return;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct perf_buffer_opts pb_opts = {};
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct perf_buffer *pb;
+	struct bpf_object *obj;
+	int map_fd, ret = 0;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (libbpf_get_error(prog)) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	pb_opts.sample_cb = print_bpf_output;
+	pb = perf_buffer__new(map_fd, 8, &pb_opts);
+	ret = libbpf_get_error(pb);
+	if (ret) {
+		printf("failed to setup perf_buffer: %d\n", ret);
+		return 1;
+	}
+
+	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
+	(void) f;
+
+	start_time = time_get_ns();
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+	}
+	kill(0, SIGINT);
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return ret;
+}