perf tools: Record whether a dso has data

Add 'data.status' to record whether a dso has data (i.e. an object
file).  This is used to avoid repeatedly creating the file name and
attempting to open a file that is not present.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1406035081-14301-10-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 22 insertions, 8 deletions

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 28cf7476b68c..8827db3d2cba 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -331,26 +331,32 @@ int dso__data_fd(struct dso *dso, struct machine *machine)
         };
         int i = 0;
 
+        if (dso->data.status == DSO_DATA_STATUS_ERROR)
+                return -1;
+
         if (dso->data.fd >= 0)
-                return dso->data.fd;
+                goto out;
 
         if (dso->binary_type != DSO_BINARY_TYPE__NOT_FOUND) {
                 dso->data.fd = open_dso(dso, machine);
-                return dso->data.fd;
+                goto out;
         }
 
         do {
-                int fd;
-
                 dso->binary_type = binary_type_data[i++];
 
-                fd = open_dso(dso, machine);
-                if (fd >= 0)
-                        return dso->data.fd = fd;
+                dso->data.fd = open_dso(dso, machine);
+                if (dso->data.fd >= 0)
+                        goto out;
 
         } while (dso->binary_type != DSO_BINARY_TYPE__NOT_FOUND);
+out:
+        if (dso->data.fd >= 0)
+                dso->data.status = DSO_DATA_STATUS_OK;
+        else
+                dso->data.status = DSO_DATA_STATUS_ERROR;
 
-        return -EINVAL;
+        return dso->data.fd;
 }
 
 static void
@@ -701,6 +707,7 @@ struct dso *dso__new(const char *name)
                         dso->symbols[i] = dso->symbol_names[i] = RB_ROOT;
                 dso->data.cache = RB_ROOT;
                 dso->data.fd = -1;
+                dso->data.status = DSO_DATA_STATUS_UNKNOWN;
                 dso->symtab_type = DSO_BINARY_TYPE__NOT_FOUND;
                 dso->binary_type = DSO_BINARY_TYPE__NOT_FOUND;
                 dso->is_64_bit = (sizeof(void *) == 8);
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index c239e86541a3..aeb7bcbf0239 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -40,6 +40,12 @@ enum dso_swap_type {
         DSO_SWAP__YES,
 };
 
+enum dso_data_status {
+        DSO_DATA_STATUS_ERROR   = -1,
+        DSO_DATA_STATUS_UNKNOWN = 0,
+        DSO_DATA_STATUS_OK      = 1,
+};
+
 #define DSO__SWAP(dso, type, val)                       \
 ({                                                      \
         type ____r = val;                               \
@@ -104,6 +110,7 @@ struct dso {
         struct {
                 struct rb_root   cache;
                 int              fd;
+                int              status;
                 size_t           file_size;
                 struct list_head open_entry;
         } data;