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-rw-r--r--samples/bpf/trace_output_user.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
new file mode 100644
index 0000000000..d316fd2c8e
--- /dev/null
+++ b/samples/bpf/trace_output_user.c
@@ -0,0 +1,105 @@
+// 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 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.bpf.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 = perf_buffer__new(map_fd, 8, print_bpf_output, NULL, NULL, NULL);
+ 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;
+}