perf tools: Mount debugfs automatically

Mount debugfs filesystem under '/sys/kernel/debug', if it's not
mounted.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <4B387090.7080407@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 873e55fab375d253d4b80d4fb1862053f21080a4..fc89005c3e51c43dccc1bb76dbe60b4ee2d25737 100644 (file)
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -388,7 +388,7 @@ static int run_argv(int *argcp, const char ***argv)
 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
 static void get_debugfs_mntpt(void)
 {
-       const char *path = debugfs_find_mountpoint();
+       const char *path = debugfs_mount(NULL);
 
        if (path)
                strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));

diff --git a/tools/perf/util/debugfs.c b/tools/perf/util/debugfs.c
index 06b73ee02c49ced2696d4ead2fcd31480d76193d..1f805fde5fd4b6f0fc32e9776409463730996573 100644 (file)
--- a/tools/perf/util/debugfs.c
+++ b/tools/perf/util/debugfs.c
@@ -106,16 +106,14 @@ int debugfs_valid_entry(const char *path)
        return 0;
 }
 
-/* mount the debugfs somewhere */
+/* mount the debugfs somewhere if it's not mounted */
 
-int debugfs_mount(const char *mountpoint)
+char *debugfs_mount(const char *mountpoint)
 {
-       char mountcmd[128];
-
        /* see if it's already mounted */
        if (debugfs_find_mountpoint()) {
                debugfs_premounted = 1;
-               return 0;
+               return debugfs_mountpoint;
        }
 
        /* if not mounted and no argument */
@@ -127,13 +125,13 @@ int debugfs_mount(const char *mountpoint)
                        mountpoint = "/sys/kernel/debug";
        }
 
+       if (mount(NULL, mountpoint, "debugfs", 0, NULL) < 0)
+               return NULL;
+
        /* save the mountpoint */
        strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint));
 
-       /* mount it */
-       snprintf(mountcmd, sizeof(mountcmd),
-                "/bin/mount -t debugfs debugfs %s", mountpoint);
-       return system(mountcmd);
+       return debugfs_mountpoint;
 }
 
 /* umount the debugfs */

diff --git a/tools/perf/util/debugfs.h b/tools/perf/util/debugfs.h
index 3cd14f9ae784533de54c314d015ea73a48bff769..83a02879745f5392bd065db31c522a98cf2a7165 100644 (file)
--- a/tools/perf/util/debugfs.h
+++ b/tools/perf/util/debugfs.h
@@ -15,7 +15,7 @@
 extern const char *debugfs_find_mountpoint(void);
 extern int debugfs_valid_mountpoint(const char *debugfs);
 extern int debugfs_valid_entry(const char *path);
-extern int debugfs_mount(const char *mountpoint);
+extern char *debugfs_mount(const char *mountpoint);
 extern int debugfs_umount(void);
 extern int debugfs_write(const char *entry, const char *value);
 extern int debugfs_read(const char *entry, char *buffer, size_t size);