1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 #ifndef __LIBPERF_BPF_PERF_H 3 #define __LIBPERF_BPF_PERF_H 4 5 #include <linux/types.h> /* for __u32 */ 6 7 /* 8 * bpf_perf uses a hashmap, the attr_map, to track all the leader programs. 9 * The hashmap is pinned in bpffs. flock() on this file is used to ensure 10 * no concurrent access to the attr_map. The key of attr_map is struct 11 * perf_event_attr, and the value is struct perf_event_attr_map_entry. 12 * 13 * struct perf_event_attr_map_entry contains two __u32 IDs, bpf_link of the 14 * leader prog, and the diff_map. Each perf-stat session holds a reference 15 * to the bpf_link to make sure the leader prog is attached to sched_switch 16 * tracepoint. 17 * 18 * Since the hashmap only contains IDs of the bpf_link and diff_map, it 19 * does not hold any references to the leader program. Once all perf-stat 20 * sessions of these events exit, the leader prog, its maps, and the 21 * perf_events will be freed. 22 */ 23 struct perf_event_attr_map_entry { 24 __u32 link_id; 25 __u32 diff_map_id; 26 }; 27 28 /* default attr_map name */ 29 #define BPF_PERF_DEFAULT_ATTR_MAP_PATH "perf_attr_map" 30 31 #endif /* __LIBPERF_BPF_PERF_H */ 32