perf tools: Simplify debugfs mountpoint handling code

We don't need to have two PATH_MAX char sized arrays holding it, just
one in util/debugfs.c will do.

Also rename debugfs_path to tracing_events_path, as it is not the path
to debugfs, that is debugfs_mountpoint. Both are now accessible.

This will allow accessing this code in the perf python binding without
having to drag in perf.c and util/parse-events.c.

The defaults for these variables are the canonical "/sys/kernel/debug"
and "/sys/kernel/debug/tracing/events/", removing the need for simple
tools to call debugfs_mount(NULL).

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ug9jvtjrsqbluuhqqxpvg30f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 13 insertions, 15 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 928918b796b2..586ab3fe60f8 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -25,8 +25,6 @@ enum event_result {
         EVT_HANDLED_ALL
 };
 
-char debugfs_path[MAXPATHLEN];
-
 #define CHW(x) .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_##x
 #define CSW(x) .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_##x
 
@@ -140,7 +138,7 @@ static int tp_event_has_id(struct dirent *sys_dir, struct dirent *evt_dir)
         char evt_path[MAXPATHLEN];
         int fd;
 
-        snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", debugfs_path,
+        snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", tracing_events_path,
                         sys_dir->d_name, evt_dir->d_name);
         fd = open(evt_path, O_RDONLY);
         if (fd < 0)
@@ -171,16 +169,16 @@ struct tracepoint_path *tracepoint_id_to_path(u64 config)
         char evt_path[MAXPATHLEN];
         char dir_path[MAXPATHLEN];
 
-        if (debugfs_valid_mountpoint(debugfs_path))
+        if (debugfs_valid_mountpoint(tracing_events_path))
                 return NULL;
 
-        sys_dir = opendir(debugfs_path);
+        sys_dir = opendir(tracing_events_path);
         if (!sys_dir)
                 return NULL;
 
         for_each_subsystem(sys_dir, sys_dirent, sys_next) {
 
-                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
                          sys_dirent.d_name);
                 evt_dir = opendir(dir_path);
                 if (!evt_dir)
@@ -447,7 +445,7 @@ parse_single_tracepoint_event(char *sys_name,
         u64 id;
         int fd;
 
-        snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", debugfs_path,
+        snprintf(evt_path, MAXPATHLEN, "%s/%s/%s/id", tracing_events_path,
                  sys_name, evt_name);
 
         fd = open(evt_path, O_RDONLY);
@@ -485,7 +483,7 @@ parse_multiple_tracepoint_event(struct perf_evlist *evlist, char *sys_name,
         struct dirent *evt_ent;
         DIR *evt_dir;
 
-        snprintf(evt_path, MAXPATHLEN, "%s/%s", debugfs_path, sys_name);
+        snprintf(evt_path, MAXPATHLEN, "%s/%s", tracing_events_path, sys_name);
         evt_dir = opendir(evt_path);
 
         if (!evt_dir) {
@@ -528,7 +526,7 @@ parse_tracepoint_event(struct perf_evlist *evlist, const char **strp,
         char sys_name[MAX_EVENT_LENGTH];
         unsigned int sys_length, evt_length;
 
-        if (debugfs_valid_mountpoint(debugfs_path))
+        if (debugfs_valid_mountpoint(tracing_events_path))
                 return 0;
 
         evt_name = strchr(*strp, ':');
@@ -920,10 +918,10 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob)
         char evt_path[MAXPATHLEN];
         char dir_path[MAXPATHLEN];
 
-        if (debugfs_valid_mountpoint(debugfs_path))
+        if (debugfs_valid_mountpoint(tracing_events_path))
                 return;
 
-        sys_dir = opendir(debugfs_path);
+        sys_dir = opendir(tracing_events_path);
         if (!sys_dir)
                 return;
 
@@ -932,7 +930,7 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob)
                     !strglobmatch(sys_dirent.d_name, subsys_glob))
                         continue;
 
-                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
                          sys_dirent.d_name);
                 evt_dir = opendir(dir_path);
                 if (!evt_dir)
@@ -964,16 +962,16 @@ int is_valid_tracepoint(const char *event_string)
         char evt_path[MAXPATHLEN];
         char dir_path[MAXPATHLEN];
 
-        if (debugfs_valid_mountpoint(debugfs_path))
+        if (debugfs_valid_mountpoint(tracing_events_path))
                 return 0;
 
-        sys_dir = opendir(debugfs_path);
+        sys_dir = opendir(tracing_events_path);
         if (!sys_dir)
                 return 0;
 
         for_each_subsystem(sys_dir, sys_dirent, sys_next) {
 
-                snprintf(dir_path, MAXPATHLEN, "%s/%s", debugfs_path,
+                snprintf(dir_path, MAXPATHLEN, "%s/%s", tracing_events_path,
                          sys_dirent.d_name);
                 evt_dir = opendir(dir_path);
                 if (!evt_dir)