perf evlist: Introduce set_filter_pid method

To filter out events for a certain pid, for instance, when tracing
system wide, so that the tracer itself doesn't creates an event loop.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-byoia9dzu4gmkdv87etnd9zf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 14 insertions, 0 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index a8b2c5726aba..39302a455a58 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1085,6 +1085,19 @@ int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
         return err;
 }
 
+int perf_evlist__set_filter_pid(struct perf_evlist *evlist, pid_t pid)
+{
+        char *filter;
+        int ret;
+
+        if (asprintf(&filter, "common_pid != %d", pid) < 0)
+                return -1;
+
+        ret = perf_evlist__set_filter(evlist, filter);
+        free(filter);
+        return ret;
+}
+
 bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
 {
         struct perf_evsel *pos;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index c94a9e03ecf1..715fa3a296f4 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -77,6 +77,7 @@ int perf_evlist__add_newtp(struct perf_evlist *evlist,
                            const char *sys, const char *name, void *handler);
 
 int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter);
+int perf_evlist__set_filter_pid(struct perf_evlist *evlist, pid_t pid);
 
 struct perf_evsel *
 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id);