[PATCH v2 5/8] libperf: Add perf_evsel__has_fd() functions

Charlie Jenkins
2024-07-29T16:46:15Z

Add the following functions:

perf_evsel__has_fd

to check for perf events with the file descriptor specified in the
argument.
This function can be used in signal handlers to check overflow.

Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
tools/lib/perf/Documentation/libperf.txt | 1 +
tools/lib/perf/evsel.c | 18 ++++++++++++++++++
tools/lib/perf/include/perf/evsel.h | 1 +
tools/lib/perf/libperf.map | 1 +
4 files changed, 21 insertions(+)

diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt
index bb99534d5855..f1bfe6b6e78a 100644
--- a/tools/lib/perf/Documentation/libperf.txt
+++ b/tools/lib/perf/Documentation/libperf.txt
@@ -161,6 +161,7 @@ SYNOPSIS
int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu_map_idx);
int perf_evsel__disable(struct perf_evsel *evsel);
int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu_map_idx);
+ bool perf_evsel__has_fd(struct perf_evsel *evsel, int fd);
struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel);
struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel);
struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel);
diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index 17d3d9a88c23..6b98cba6eb4f 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c
@@ -658,3 +658,21 @@ int perf_evsel__open_opts(struct perf_evsel *evsel, struct perf_cpu_map *cpus,

return err;
}
+
+bool perf_evsel__has_fd(struct perf_evsel *evsel, int fd)
+{
+ int cpu_map_idx;
+ int thread;
+ int *evsel_fd;
+
+ for (cpu_map_idx = 0; cpu_map_idx < xyarray__max_x(evsel->fd); ++cpu_map_idx) {
+ for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
+ evsel_fd = FD(evsel, cpu_map_idx, thread);
+
+ if (fd == *evsel_fd)
+ return true;
+ }
+ }
+
+ return false;
+}
diff --git a/tools/lib/perf/include/perf/evsel.h b/tools/lib/perf/include/perf/evsel.h
index 344808f23371..77816a35c383 100644
--- a/tools/lib/perf/include/perf/evsel.h
+++ b/tools/lib/perf/include/perf/evsel.h
@@ -73,5 +73,6 @@ LIBPERF_API int perf_evsel__open_opts(struct perf_evsel *evsel,
struct perf_cpu_map *cpus,
struct perf_thread_map *threads,
struct perf_evsel_open_opts *opts);
+LIBPERF_API bool perf_evsel__has_fd(struct perf_evsel *evsel, int fd);

#endif /* __LIBPERF_EVSEL_H */
diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map
index 84fed76621cb..f68519e17885 100644
--- a/tools/lib/perf/libperf.map
+++ b/tools/lib/perf/libperf.map
@@ -38,6 +38,7 @@ LIBPERF_0.0.1 {
perf_evsel__cpus;
perf_evsel__threads;
perf_evsel__attr;
+ perf_evsel__has_fd;
perf_evlist__new;
perf_evlist__delete;
perf_evlist__open;

--
2.44.0