perf tools: Fix dso__data_read_offset() file opening

When dso__data_read_offset/addr() is called without prior dso__data_fd()
(or other functions which call it internally), it failed to open dso in
data_file_size() since its binary type was not identified.

However calling dso__data_fd() in dso__data_read_offset() will hurt
performance as it grabs a global lock everytime.  So factor out the loop
on the binary type in dso__data_fd(), and call it from both.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1432137821-10853-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 1b96c8d..516e0c2 100644 (file)
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -440,15 +440,7 @@ void dso__data_close(struct dso *dso)
        pthread_mutex_unlock(&dso__data_open_lock);
 }
 
-/**
- * dso__data_fd - Get dso's data file descriptor
- * @dso: dso object
- * @machine: machine object
- *
- * External interface to find dso's file, open it and
- * returns file descriptor.
- */
-int dso__data_fd(struct dso *dso, struct machine *machine)
+static void try_to_open_dso(struct dso *dso, struct machine *machine)
 {
        enum dso_binary_type binary_type_data[] = {
                DSO_BINARY_TYPE__BUILD_ID_CACHE,
@@ -457,13 +449,8 @@ int dso__data_fd(struct dso *dso, struct machine *machine)
        };
        int i = 0;
 
-       if (dso->data.status == DSO_DATA_STATUS_ERROR)
-               return -1;
-
-       pthread_mutex_lock(&dso__data_open_lock);
-
        if (dso->data.fd >= 0)
-               goto out;
+               return;
 
        if (dso->binary_type != DSO_BINARY_TYPE__NOT_FOUND) {
                dso->data.fd = open_dso(dso, machine);
@@ -483,8 +470,25 @@ out:
                dso->data.status = DSO_DATA_STATUS_OK;
        else
                dso->data.status = DSO_DATA_STATUS_ERROR;
+}
+
+/**
+ * dso__data_fd - Get dso's data file descriptor
+ * @dso: dso object
+ * @machine: machine object
+ *
+ * External interface to find dso's file, open it and
+ * returns file descriptor.
+ */
+int dso__data_fd(struct dso *dso, struct machine *machine)
+{
+       if (dso->data.status == DSO_DATA_STATUS_ERROR)
+               return -1;
 
+       pthread_mutex_lock(&dso__data_open_lock);
+       try_to_open_dso(dso, machine);
        pthread_mutex_unlock(&dso__data_open_lock);
+
        return dso->data.fd;
 }
 
@@ -609,13 +613,12 @@ dso_cache__read(struct dso *dso, struct machine *machine,
                 * dso->data.fd might be closed if other thread opened another
                 * file (dso) due to open file limit (RLIMIT_NOFILE).
                 */
+               try_to_open_dso(dso, machine);
+
                if (dso->data.fd < 0) {
-                       dso->data.fd = open_dso(dso, machine);
-                       if (dso->data.fd < 0) {
-                               ret = -errno;
-                               dso->data.status = DSO_DATA_STATUS_ERROR;
-                               break;
-                       }
+                       ret = -errno;
+                       dso->data.status = DSO_DATA_STATUS_ERROR;
+                       break;
                }
 
                cache_offset = offset & DSO__DATA_CACHE_MASK;
@@ -702,19 +705,21 @@ static int data_file_size(struct dso *dso, struct machine *machine)
        if (dso->data.file_size)
                return 0;
 
+       if (dso->data.status == DSO_DATA_STATUS_ERROR)
+               return -1;
+
        pthread_mutex_lock(&dso__data_open_lock);
 
        /*
         * dso->data.fd might be closed if other thread opened another
         * file (dso) due to open file limit (RLIMIT_NOFILE).
         */
+       try_to_open_dso(dso, machine);
+
        if (dso->data.fd < 0) {
-               dso->data.fd = open_dso(dso, machine);
-               if (dso->data.fd < 0) {
-                       ret = -errno;
-                       dso->data.status = DSO_DATA_STATUS_ERROR;
-                       goto out;
-               }
+               ret = -errno;
+               dso->data.status = DSO_DATA_STATUS_ERROR;
+               goto out;
        }
 
        if (fstat(dso->data.fd, &st) < 0) {