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>
diff --git a/tools/perf/util/debugfs.c b/tools/perf/util/debugfs.c
index 680be34..ffc35e7 100644
--- a/tools/perf/util/debugfs.c
+++ b/tools/perf/util/debugfs.c
@@ -2,10 +2,12 @@
#include "debugfs.h"
#include "cache.h"
+#include <linux/kernel.h>
#include <sys/mount.h>
static int debugfs_premounted;
-static char debugfs_mountpoint[PATH_MAX + 1];
+char debugfs_mountpoint[PATH_MAX + 1] = "/sys/kernel/debug";
+char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";
static const char *debugfs_known_mountpoints[] = {
"/sys/kernel/debug/",
@@ -64,7 +66,7 @@
/* give up and parse /proc/mounts */
fp = fopen("/proc/mounts", "r");
if (fp == NULL)
- die("Can't open /proc/mounts for read");
+ return NULL;
while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
debugfs_mountpoint, type) == 2) {
@@ -106,6 +108,12 @@
return 0;
}
+static void debugfs_set_tracing_events_path(const char *mountpoint)
+{
+ snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
+ mountpoint, "tracing/events");
+}
+
/* mount the debugfs somewhere if it's not mounted */
char *debugfs_mount(const char *mountpoint)
@@ -113,7 +121,7 @@
/* see if it's already mounted */
if (debugfs_find_mountpoint()) {
debugfs_premounted = 1;
- return debugfs_mountpoint;
+ goto out;
}
/* if not mounted and no argument */
@@ -129,12 +137,19 @@
return NULL;
/* save the mountpoint */
- strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
debugfs_found = 1;
-
+ strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
+out:
+ debugfs_set_tracing_events_path(debugfs_mountpoint);
return debugfs_mountpoint;
}
+void debugfs_set_path(const char *mountpoint)
+{
+ snprintf(debugfs_mountpoint, sizeof(debugfs_mountpoint), "%s", mountpoint);
+ debugfs_set_tracing_events_path(mountpoint);
+}
+
/* umount the debugfs */
int debugfs_umount(void)
diff --git a/tools/perf/util/debugfs.h b/tools/perf/util/debugfs.h
index 8cd3fa0..4a878f7 100644
--- a/tools/perf/util/debugfs.h
+++ b/tools/perf/util/debugfs.h
@@ -6,9 +6,13 @@
int debugfs_valid_entry(const char *path);
char *debugfs_mount(const char *mountpoint);
int debugfs_umount(void);
+void debugfs_set_path(const char *mountpoint);
int debugfs_write(const char *entry, const char *value);
int debugfs_read(const char *entry, char *buffer, size_t size);
void debugfs_force_cleanup(void);
int debugfs_make_path(const char *element, char *buffer, int size);
+extern char debugfs_mountpoint[];
+extern char tracing_events_path[];
+
#endif /* __DEBUGFS_H__ */
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 928918b..586ab3f 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -25,8 +25,6 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
!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 @@
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)
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 2f8e375..7e0cbe7 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -39,7 +39,6 @@
int print_hwcache_events(const char *event_glob);
extern int is_valid_tracepoint(const char *event_string);
-extern char debugfs_path[];
extern int valid_debugfs_mount(const char *debugfs);
#endif /* __PERF_PARSE_EVENTS_H */