// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) // Copyright (c) 2021 Facebook #include <linux/bpf.h> #include <linux/perf_event.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include "bperf.h" struct { __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); __uint(key_size, sizeof(__u32)); __uint(value_size, sizeof(int)); __uint(map_flags, BPF_F_PRESERVE_ELEMS); } events SEC(".maps"); reading_map prev_readings SEC(".maps"); reading_map diff_readings SEC(".maps"); SEC("raw_tp/sched_switch") int BPF_PROG(on_switch) { struct bpf_perf_event_value val, *prev_val, *diff_val; __u32 key = bpf_get_smp_processor_id(); __u32 zero = 0; long err; prev_val = bpf_map_lookup_elem(&prev_readings, &zero); if (!prev_val) return 0; diff_val = bpf_map_lookup_elem(&diff_readings, &zero); if (!diff_val) return 0; err = bpf_perf_event_read_value(&events, key, &val, sizeof(val)); if (err) return 0; diff_val->counter = val.counter - prev_val->counter; diff_val->enabled = val.enabled - prev_val->enabled; diff_val->running = val.running - prev_val->running; *prev_val = val; return 0; } char LICENSE[] SEC("license") = "Dual BSD/GPL";