[PATCH] tools/lib/perf: add a flag to specify cgroup fd
From: Jinshan Xiong <hidden>
Date: 2021-09-26 02:17:07
Also in:
lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
This patch adds an API perf_thread_map__set_flags() so that we can use
it to pass down a flag to specific cgroup fd in sys_perf_event_open().
This API can be used in the following way:
int cgroup_fd = open("/sys/fs/cgroup/perf_event", O_RDONLY);
struct thread_map *threadmap = perf_thread_map__new_dummy();
perf_thread_map__set_pid(threadmap, 0, cgroup_fd);
perf_thread_map__set_flags(threadmap, 0, PERF_FLAG_PID_CGROUP);
Therefore, we can only collect perf events in a specific docker
container.
Signed-off-by: Jinshan Xiong <redacted>
---
tools/lib/perf/evsel.c | 3 ++-
tools/lib/perf/include/internal/threadmap.h | 1 +
tools/lib/perf/include/perf/threadmap.h | 1 +
tools/lib/perf/threadmap.c | 5 +++++
4 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index 8441e3e1aaac..67f86513a816 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c@@ -153,7 +153,8 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, fd = sys_perf_event_open(&evsel->attr, threads->map[thread].pid, - cpus->map[cpu], group_fd, 0); + cpus->map[cpu], group_fd, + threads->map[thread].flags); if (fd < 0) return -errno;
diff --git a/tools/lib/perf/include/internal/threadmap.h b/tools/lib/perf/include/internal/threadmap.h
index df748baf9eda..5d7bd6968563 100644
--- a/tools/lib/perf/include/internal/threadmap.h
+++ b/tools/lib/perf/include/internal/threadmap.h@@ -8,6 +8,7 @@ struct thread_map_data { pid_t pid; + int flags; char *comm; };
diff --git a/tools/lib/perf/include/perf/threadmap.h b/tools/lib/perf/include/perf/threadmap.h
index a7c50de8d010..5fea1a403e28 100644
--- a/tools/lib/perf/include/perf/threadmap.h
+++ b/tools/lib/perf/include/perf/threadmap.h@@ -10,6 +10,7 @@ struct perf_thread_map; LIBPERF_API struct perf_thread_map *perf_thread_map__new_dummy(void); LIBPERF_API void perf_thread_map__set_pid(struct perf_thread_map *map, int thread, pid_t pid); +LIBPERF_API void perf_thread_map__set_flags(struct perf_thread_map *map, int thread, int flags); LIBPERF_API char *perf_thread_map__comm(struct perf_thread_map *map, int thread); LIBPERF_API int perf_thread_map__nr(struct perf_thread_map *threads); LIBPERF_API pid_t perf_thread_map__pid(struct perf_thread_map *map, int thread);
diff --git a/tools/lib/perf/threadmap.c b/tools/lib/perf/threadmap.c
index e92c368b0a6c..3b8ec4f944b9 100644
--- a/tools/lib/perf/threadmap.c
+++ b/tools/lib/perf/threadmap.c@@ -37,6 +37,11 @@ void perf_thread_map__set_pid(struct perf_thread_map *map, int thread, pid_t pid map->map[thread].pid = pid; } +void perf_thread_map__set_flags(struct perf_thread_map *map, int thread, int flags) +{ + map->map[thread].flags = flags; +} + char *perf_thread_map__comm(struct perf_thread_map *map, int thread) { return map->map[thread].comm;
--
2.30.2