tools/testing/selftests/bpf/progs/perfbuf_bench.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2020 Facebook
   3
   4 #include <linux/bpf.h>
   5 #include <stdint.h>
   6 #include <bpf/bpf_helpers.h>
   7
   8 char _license[] SEC("license") = "GPL";
   9
  10 struct {
  11         __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
  12         __uint(value_size, sizeof(int));
  13         __uint(key_size, sizeof(int));
  14 } perfbuf SEC(".maps");
  15
  16 const volatile int batch_cnt = 0;
  17
  18 long sample_val = 42;
  19 long dropped __attribute__((aligned(128))) = 0;
  20
  21 SEC("fentry/__x64_sys_getpgid")
  22 int bench_perfbuf(void *ctx)
  23 {
  24         __u64 *sample;
  25         int i;
  26
  27         for (i = 0; i < batch_cnt; i++) {
  28                 if (bpf_perf_event_output(ctx, &perfbuf, BPF_F_CURRENT_CPU,
  29                                           &sample_val, sizeof(sample_val)))
  30                         __sync_add_and_fetch(&dropped, 1);
  31         }
  32         return 0;
  33 }