linux/tools/perf/util/bpf_skel/bperf_follower.bpf.c
Song Liu 5a897531e0 perf bpf_skel: Do not use typedef to avoid error on old clang
When building bpf_skel with clang-10, typedef causes confusions like:

  libbpf: map 'prev_readings': unexpected def kind var.

Fix this by removing the typedef.

Fixes: 7fac83aaf2 ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/BEF5C312-4331-4A60-AEC0-AD7617CB2BC4@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-12-06 21:57:53 -03:00

79 lines
1.7 KiB
C

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (c) 2021 Facebook
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bperf_u.h"
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(struct bpf_perf_event_value));
__uint(max_entries, 1);
} diff_readings SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(struct bpf_perf_event_value));
__uint(max_entries, 1);
} accum_readings SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(__u32));
} filter SEC(".maps");
enum bperf_filter_type type = 0;
int enabled = 0;
SEC("fexit/XXX")
int BPF_PROG(fexit_XXX)
{
struct bpf_perf_event_value *diff_val, *accum_val;
__u32 filter_key, zero = 0;
__u32 *accum_key;
if (!enabled)
return 0;
switch (type) {
case BPERF_FILTER_GLOBAL:
accum_key = &zero;
goto do_add;
case BPERF_FILTER_CPU:
filter_key = bpf_get_smp_processor_id();
break;
case BPERF_FILTER_PID:
filter_key = bpf_get_current_pid_tgid() & 0xffffffff;
break;
case BPERF_FILTER_TGID:
filter_key = bpf_get_current_pid_tgid() >> 32;
break;
default:
return 0;
}
accum_key = bpf_map_lookup_elem(&filter, &filter_key);
if (!accum_key)
return 0;
do_add:
diff_val = bpf_map_lookup_elem(&diff_readings, &zero);
if (!diff_val)
return 0;
accum_val = bpf_map_lookup_elem(&accum_readings, accum_key);
if (!accum_val)
return 0;
accum_val->counter += diff_val->counter;
accum_val->enabled += diff_val->enabled;
accum_val->running += diff_val->running;
return 0;
}
char LICENSE[] SEC("license") = "Dual BSD/GPL";