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>

1 files changed, 32 insertions, 27 deletions

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 1b96c8d18435..516e0c25ea16 100644
--- 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) {