perf tools: Make perf aware of tracefs

As tracefs may be mounted instead of debugfs to get to the event
directories, have perf know about tracefs, and use that file system over
debugfs if it is present.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150202193553.340946602@goodmis.org
[ Fixed up error messages about tracefs pointed out by Namhyung ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/tests/open-syscall-all-cpus.c b/tools/perf/tests/open-syscall-all-cpus.c
index 8fa82d1700c725f13519ef24ca4a8fbe8b235ea3..3ec885c48f8fbcc77bdeaf0891fa54a2aa3935bc 100644 (file)
--- a/tools/perf/tests/open-syscall-all-cpus.c
+++ b/tools/perf/tests/open-syscall-all-cpus.c
@@ -29,7 +29,12 @@ int test__open_syscall_event_on_all_cpus(void)
 
        evsel = perf_evsel__newtp("syscalls", "sys_enter_open");
        if (evsel == NULL) {
-               pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
+               if (tracefs_configured())
+                       pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
+               else if (debugfs_configured())
+                       pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
+               else
+                       pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
                goto out_thread_map_delete;
        }
 

diff --git a/tools/perf/tests/open-syscall.c b/tools/perf/tests/open-syscall.c
index a33b2daae40f5239daa299a9a5335de26b39b420..07aa319bf334f37cc63d5c17efacce2faca54676 100644 (file)
--- a/tools/perf/tests/open-syscall.c
+++ b/tools/perf/tests/open-syscall.c
@@ -18,7 +18,12 @@ int test__open_syscall_event(void)
 
        evsel = perf_evsel__newtp("syscalls", "sys_enter_open");
        if (evsel == NULL) {
-               pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
+               if (tracefs_configured())
+                       pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
+               else if (debugfs_configured())
+                       pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
+               else
+                       pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
                goto out_thread_map_delete;
        }
 

diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 1cdab0ce00e2e4b291750a4dbaeef0229a599733..ac243ebcb20a224992a1ebb73ebd91afecddaf67 100644 (file)
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -3,6 +3,7 @@
 #include "evsel.h"
 #include "evlist.h"
 #include <api/fs/fs.h>
+#include <api/fs/tracefs.h>
 #include <api/fs/debugfs.h>
 #include "tests.h"
 #include "debug.h"
@@ -1192,11 +1193,19 @@ static int count_tracepoints(void)
 {
        char events_path[PATH_MAX];
        struct dirent *events_ent;
+       const char *mountpoint;
        DIR *events_dir;
        int cnt = 0;
 
-       scnprintf(events_path, PATH_MAX, "%s/tracing/events",
-                 debugfs_find_mountpoint());
+       mountpoint = tracefs_find_mountpoint();
+       if (mountpoint) {
+               scnprintf(events_path, PATH_MAX, "%s/events",
+                         mountpoint);
+       } else {
+               mountpoint = debugfs_find_mountpoint();
+               scnprintf(events_path, PATH_MAX, "%s/tracing/events",
+                         mountpoint);
+       }
 
        events_dir = opendir(events_path);
 

diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index d04d770d90f6e29bc17d4d5d1299e76278b5ee1c..fbcca21d66ab9b6887f084b19bdff98109201612 100644 (file)
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -17,6 +17,7 @@
 #define EXEC_PATH_ENVIRONMENT "PERF_EXEC_PATH"
 #define DEFAULT_PERF_DIR_ENVIRONMENT ".perf"
 #define PERF_DEBUGFS_ENVIRONMENT "PERF_DEBUGFS_DIR"
+#define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR"
 
 typedef int (*config_fn_t)(const char *, const char *, void *);
 extern int perf_default_config(const char *, const char *, void *);

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index c602ebb5b9914bec29272fd84cece63ad3b69a32..a8b2c5726abacbf3dfbf8592cdbb2a92da98774c 100644 (file)
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -7,7 +7,6 @@
  * Released under the GPL v2. (and only v2, not any later version)
  */
 #include "util.h"
-#include <api/fs/debugfs.h>
 #include <api/fs/fs.h>
 #include <poll.h>
 #include "cpumap.h"

diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index ff6e1fa4111ec7dca08c4e90da7ef14984e602cb..39c3b57965d185e8c17faee087e8620d723a5513 100644 (file)
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -122,6 +122,6 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob,
 int print_hwcache_events(const char *event_glob, bool name_only);
 extern int is_valid_tracepoint(const char *event_string);
 
-extern int valid_debugfs_mount(const char *debugfs);
+int valid_event_mount(const char *eventfs);
 
 #endif /* __PERF_PARSE_EVENTS_H */

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 919937eb0be2b643e93bfe7fc983e7131074deeb..9dfbed96bf397c81268f32c88b52e6d19c6253fb 100644 (file)
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -41,6 +41,7 @@
 #include "symbol.h"
 #include "thread.h"
 #include <api/fs/debugfs.h>
+#include <api/fs/tracefs.h>
 #include "trace-event.h"       /* For __maybe_unused */
 #include "probe-event.h"
 #include "probe-finder.h"
@@ -1805,7 +1806,7 @@ static void print_open_warning(int err, bool is_kprobe)
                           " - please rebuild kernel with %s.\n",
                           is_kprobe ? 'k' : 'u', config);
        } else if (err == -ENOTSUP)
-               pr_warning("Debugfs is not mounted.\n");
+               pr_warning("Tracefs or debugfs is not mounted.\n");
        else
                pr_warning("Failed to open %cprobe_events: %s\n",
                           is_kprobe ? 'k' : 'u',
@@ -1816,7 +1817,7 @@ static void print_both_open_warning(int kerr, int uerr)
 {
        /* Both kprobes and uprobes are disabled, warn it. */
        if (kerr == -ENOTSUP && uerr == -ENOTSUP)
-               pr_warning("Debugfs is not mounted.\n");
+               pr_warning("Tracefs or debugfs is not mounted.\n");
        else if (kerr == -ENOENT && uerr == -ENOENT)
                pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
                           "or/and CONFIG_UPROBE_EVENTS.\n");
@@ -1833,13 +1834,20 @@ static int open_probe_events(const char *trace_file, bool readwrite)
 {
        char buf[PATH_MAX];
        const char *__debugfs;
+       const char *tracing_dir = "";
        int ret;
 
-       __debugfs = debugfs_find_mountpoint();
-       if (__debugfs == NULL)
-               return -ENOTSUP;
+       __debugfs = tracefs_find_mountpoint();
+       if (__debugfs == NULL) {
+               tracing_dir = "tracing/";
 
-       ret = e_snprintf(buf, PATH_MAX, "%s/%s", __debugfs, trace_file);
+               __debugfs = debugfs_find_mountpoint();
+               if (__debugfs == NULL)
+                       return -ENOTSUP;
+       }
+
+       ret = e_snprintf(buf, PATH_MAX, "%s/%s%s",
+                        __debugfs, tracing_dir, trace_file);
        if (ret >= 0) {
                pr_debug("Opening %s write=%d\n", buf, readwrite);
                if (readwrite && !probe_event_dry_run)
@@ -1855,12 +1863,12 @@ static int open_probe_events(const char *trace_file, bool readwrite)
 
 static int open_kprobe_events(bool readwrite)
 {
-       return open_probe_events("tracing/kprobe_events", readwrite);
+       return open_probe_events("kprobe_events", readwrite);
 }
 
 static int open_uprobe_events(bool readwrite)
 {
-       return open_probe_events("tracing/uprobe_events", readwrite);
+       return open_probe_events("uprobe_events", readwrite);
 }
 
 /* Get raw string list of current kprobe_events  or uprobe_events */

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index b86744f29eeffce074d2c11fd11c5330ac72bfaa..92db3f156b63d493e798620c8dbe309f0b8d3350 100644 (file)
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -303,13 +303,26 @@ void set_term_quiet_input(struct termios *old)
        tcsetattr(0, TCSANOW, &tc);
 }
 
-static void set_tracing_events_path(const char *mountpoint)
+static void set_tracing_events_path(const char *tracing, const char *mountpoint)
 {
-       snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s",
-                mountpoint, "tracing/events");
+       snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
+                mountpoint, tracing, "events");
 }
 
-const char *perf_debugfs_mount(const char *mountpoint)
+static const char *__perf_tracefs_mount(const char *mountpoint)
+{
+       const char *mnt;
+
+       mnt = tracefs_mount(mountpoint);
+       if (!mnt)
+               return NULL;
+
+       set_tracing_events_path("", mnt);
+
+       return mnt;
+}
+
+static const char *__perf_debugfs_mount(const char *mountpoint)
 {
        const char *mnt;
 
@@ -317,7 +330,20 @@ const char *perf_debugfs_mount(const char *mountpoint)
        if (!mnt)
                return NULL;
 
-       set_tracing_events_path(mnt);
+       set_tracing_events_path("tracing/", mnt);
+
+       return mnt;
+}
+
+const char *perf_debugfs_mount(const char *mountpoint)
+{
+       const char *mnt;
+
+       mnt = __perf_tracefs_mount(mountpoint);
+       if (mnt)
+               return mnt;
+
+       mnt = __perf_debugfs_mount(mountpoint);
 
        return mnt;
 }
@@ -325,12 +351,19 @@ const char *perf_debugfs_mount(const char *mountpoint)
 void perf_debugfs_set_path(const char *mntpt)
 {
        snprintf(debugfs_mountpoint, strlen(debugfs_mountpoint), "%s", mntpt);
-       set_tracing_events_path(mntpt);
+       set_tracing_events_path("tracing/", mntpt);
+}
+
+static const char *find_tracefs(void)
+{
+       const char *path = __perf_tracefs_mount(NULL);
+
+       return path;
 }
 
 static const char *find_debugfs(void)
 {
-       const char *path = perf_debugfs_mount(NULL);
+       const char *path = __perf_debugfs_mount(NULL);
 
        if (!path)
                fprintf(stderr, "Your kernel does not support the debugfs filesystem");
@@ -344,6 +377,7 @@ static const char *find_debugfs(void)
  */
 const char *find_tracing_dir(void)
 {
+       const char *tracing_dir = "";
        static char *tracing;
        static int tracing_found;
        const char *debugfs;
@@ -351,11 +385,15 @@ const char *find_tracing_dir(void)
        if (tracing_found)
                return tracing;
 
-       debugfs = find_debugfs();
-       if (!debugfs)
-               return NULL;
+       debugfs = find_tracefs();
+       if (!debugfs) {
+               tracing_dir = "/tracing";
+               debugfs = find_debugfs();
+               if (!debugfs)
+                       return NULL;
+       }
 
-       if (asprintf(&tracing, "%s/tracing", debugfs) < 0)
+       if (asprintf(&tracing, "%s%s", debugfs, tracing_dir) < 0)
                return NULL;
 
        tracing_found = 1;

diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 027a5153495c8c9a087b7f624ba00d6e7f309a6f..73c2f8e557abf1becc2a8dc51336647e678114c7 100644 (file)
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -75,6 +75,7 @@
 #include <linux/types.h>
 #include <sys/ttydefaults.h>
 #include <api/fs/debugfs.h>
+#include <api/fs/tracefs.h>
 #include <termios.h>
 #include <linux/bitops.h>
 #include <termios.h>