perf unwind: Add initialized arg into unwind__prepare_access

Adding initialized arg into unwind__prepare_access to get feedback about
the initialization state.

It's not possible to get it from error code, because we return 0 even in
case we don't recognize dso, which is valid.

The 'initialized' value is used in following patch to speedup
unwind__prepare_access calls logic in fork path.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1467634583-29147-4-git-send-email-jolsa@kernel.org
[ Remove ; after static inline function signatures, fixes build break ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 16 insertions, 6 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index f30f9566fddc..2439b122a4e4 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -202,7 +202,7 @@ int thread__insert_map(struct thread *thread, struct map *map)
 {
         int ret;
 
-        ret = unwind__prepare_access(thread, map);
+        ret = unwind__prepare_access(thread, map, NULL);
         if (ret)
                 return ret;
 
diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
index 854711966cad..6d542a4e0648 100644
--- a/tools/perf/util/unwind-libunwind.c
+++ b/tools/perf/util/unwind-libunwind.c
@@ -14,15 +14,19 @@ static void unwind__register_ops(struct thread *thread,
         thread->unwind_libunwind_ops = ops;
 }
 
-int unwind__prepare_access(struct thread *thread, struct map *map)
+int unwind__prepare_access(struct thread *thread, struct map *map,
+                           bool *initialized)
 {
         const char *arch;
         enum dso_type dso_type;
         struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
+        int err;
 
         if (thread->addr_space) {
                 pr_debug("unwind: thread map already set, dso=%s\n",
                          map->dso->name);
+                if (initialized)
+                        *initialized = true;
                 return 0;
         }
 
@@ -51,7 +55,10 @@ int unwind__prepare_access(struct thread *thread, struct map *map)
 out_register:
         unwind__register_ops(thread, ops);
 
-        return thread->unwind_libunwind_ops->prepare_access(thread);
+        err = thread->unwind_libunwind_ops->prepare_access(thread);
+        if (initialized)
+                *initialized = err ? false : true;
+        return err;
 }
 
 void unwind__flush_access(struct thread *thread)
diff --git a/tools/perf/util/unwind.h b/tools/perf/util/unwind.h
index 84c6d44d52f9..61fb1e90ff51 100644
--- a/tools/perf/util/unwind.h
+++ b/tools/perf/util/unwind.h
@@ -42,12 +42,14 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
 #endif
 
 int LIBUNWIND__ARCH_REG_ID(int regnum);
-int unwind__prepare_access(struct thread *thread, struct map *map);
+int unwind__prepare_access(struct thread *thread, struct map *map,
+                           bool *initialized);
 void unwind__flush_access(struct thread *thread);
 void unwind__finish_access(struct thread *thread);
 #else
 static inline int unwind__prepare_access(struct thread *thread __maybe_unused,
-                                         struct map *map __maybe_unused)
+                                         struct map *map __maybe_unused,
+                                         bool *initialized __maybe_unused)
 {
         return 0;
 }
@@ -67,7 +69,8 @@ unwind__get_entries(unwind_entry_cb_t cb __maybe_unused,
 }
 
 static inline int unwind__prepare_access(struct thread *thread __maybe_unused,
-                                         struct map *map __maybe_unused)
+                                         struct map *map __maybe_unused,
+                                         bool *initialized __maybe_unused)
 {
         return 0;
 }