From ec8149fba64b719a618b432ce9eea7ce937a523c Mon Sep 17 00:00:00 2001 From: Song Liu Date: Sun, 25 Apr 2021 14:43:29 -0700 Subject: perf util: Move bpf_perf definitions to a libperf header By following the same protocol, other tools can share hardware PMCs with perf. Move perf_event_attr_map_entry and BPF_PERF_DEFAULT_ATTR_MAP_PATH to bpf_perf.h for other tools to use. Signed-off-by: Song Liu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Song Liu Cc: kernel-team@fb.com Link: https://lore.kernel.org/r/20210425214333.1090950-2-song@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/perf/include/perf/bpf_perf.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 tools/lib/perf/include/perf/bpf_perf.h (limited to 'tools/lib') diff --git a/tools/lib/perf/include/perf/bpf_perf.h b/tools/lib/perf/include/perf/bpf_perf.h new file mode 100644 index 000000000000..e7cf6ba7b674 --- /dev/null +++ b/tools/lib/perf/include/perf/bpf_perf.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ +#ifndef __LIBPERF_BPF_PERF_H +#define __LIBPERF_BPF_PERF_H + +#include /* for __u32 */ + +/* + * bpf_perf uses a hashmap, the attr_map, to track all the leader programs. + * The hashmap is pinned in bpffs. flock() on this file is used to ensure + * no concurrent access to the attr_map. The key of attr_map is struct + * perf_event_attr, and the value is struct perf_event_attr_map_entry. + * + * struct perf_event_attr_map_entry contains two __u32 IDs, bpf_link of the + * leader prog, and the diff_map. Each perf-stat session holds a reference + * to the bpf_link to make sure the leader prog is attached to sched_switch + * tracepoint. + * + * Since the hashmap only contains IDs of the bpf_link and diff_map, it + * does not hold any references to the leader program. Once all perf-stat + * sessions of these events exit, the leader prog, its maps, and the + * perf_events will be freed. + */ +struct perf_event_attr_map_entry { + __u32 link_id; + __u32 diff_map_id; +}; + +/* default attr_map name */ +#define BPF_PERF_DEFAULT_ATTR_MAP_PATH "perf_attr_map" + +#endif /* __LIBPERF_BPF_PERF_H */ -- cgit v1.2.3-70-g09d2