perf tools: Improve message about missing symtabs for deleted DSOs

Instead of:

  no symbols found in /usr/lib/gstreamer-0.10/libgsttypefindfunctions.so (deleted), maybe install a debug package?
  no symbols found in /usr/lib/gstreamer-0.10/libgstaudioconvert.so (deleted), maybe install a debug package?

We now emit:

  /usr/lib/gstreamer-0.10/libgsttypefindfunctions.so was updated, restart the long running apps that use it!
  /usr/lib/gstreamer-0.10/libgstaudioconvert.so was updated, restart the long running apps that use it!

Which is far less misleading about what the cause of the
symbol mismatch is.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1256927305-4628-3-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/map.c

@@ -75,6 +75,8 @@ struct map *map__new(struct mmap_event *event, char *cwd, int cwdlen)
 	return NULL;
 }
 
+#define DSO__DELETED "(deleted)"
+
 struct symbol *
 map__find_symbol(struct map *self, u64 ip, symbol_filter_t filter)
 {
@@ -86,8 +88,18 @@ map__find_symbol(struct map *self, u64 ip, symbol_filter_t filter)
 				   self->dso->long_name);
 			return NULL;
 		} else if (nr == 0) {
-			pr_warning("No symbols found in %s, maybe install a debug package?\n",
-				   self->dso->long_name);
+			const char *name = self->dso->long_name;
+			const size_t len = strlen(name);
+			const size_t real_len = len - sizeof(DSO__DELETED);
+
+			if (len > sizeof(DSO__DELETED) &&
+			    strcmp(name + real_len + 1, DSO__DELETED) == 0)
+				pr_warning("%.*s was updated, restart the "
+					   "long running apps that use it!\n",
+					   real_len, name);
+			else
+				pr_warning("no symbols found in %s, maybe "
+					   "install a debug package?\n", name);
 			return NULL;
 		}
 	}