perf timechart: Adjust perf timechart to the new power events

builtin-timechart must only pass -e power:xy events if they are supported by
the running kernel, otherwise try to fetch the old power:power{start,end}
events.

For this I added the tiny helper function:

   int is_valid_tracepoint(const char *event_string)

to parse-events.[hc], which could be more generic as an interface and support
hardware/software/... events, not only tracepoints, but someone else could
extend that if needed...

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
LKML-Reference: <1294073445-14812-4-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 41 insertions, 0 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 3a142e90d609..649083f27e08 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -913,6 +913,47 @@ static void print_tracepoint_events(void)
 }
 
 /*
+ * Check whether event is in <debugfs_mount_point>/tracing/events
+ */
+
+int is_valid_tracepoint(const char *event_string)
+{
+        DIR *sys_dir, *evt_dir;
+        struct dirent *sys_next, *evt_next, sys_dirent, evt_dirent;
+        char evt_path[MAXPATHLEN];
+        char dir_path[MAXPATHLEN];
+
+        if (debugfs_valid_mountpoint(debugfs_path))
+                return 0;
+
+        sys_dir = opendir(debugfs_path);
+        if (!sys_dir)
+                return 0;
+
+        for_each_subsystem(sys_dir, sys_dirent, sys_next) {
+
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                         sys_dirent.d_name);
+                evt_dir = opendir(dir_path);
+                if (!evt_dir)
+                        continue;
+
+                for_each_event(sys_dirent, evt_dir, evt_dirent, evt_next) {
+                        snprintf(evt_path, MAXPATHLEN, "%s:%s",
+                                 sys_dirent.d_name, evt_dirent.d_name);
+                        if (!strcmp(evt_path, event_string)) {
+                                closedir(evt_dir);
+                                closedir(sys_dir);
+                                return 1;
+                        }
+                }
+                closedir(evt_dir);
+        }
+        closedir(sys_dir);
+        return 0;
+}
+
+/*
  * Print the help text for the event symbols:
  */
 void print_events(void)